GIFT OF 
 Mrs. S. 3. Llontague 
 
From the collection of the 
 
 n 
 
 
 
 Prelinger 
 v Uibrary 
 t P 
 
 San Francisco, California 
 2006 
 

 Oje tfoorfoag on tfje sotttfj sitie of @reat i&ctusfjam Cjjurdj is 
 of a "Date consfOcrablg anterior to tfye first ^otoarti'0 reign : it 
 affortis a rjooti example of tlje rutie $tormau architecture so pre= 
 balent in tfje Suffolk cjurcfjes. 
 
w< 
 
 RUDIMENTARY 
 
 DICTIONARY OF TERMS 
 
 USED IN 
 
 ARCHITECTURE, CIVIL, 
 
 ARCHITECTURE, NAVAL, 
 
 BUILDING AND CONSTRUCTION, 
 
 EARLY AND ECCLESIASTICAL ART, 
 
 ENGINEERING, CIVIL, 
 ENGINEERING, MECHANICAL, 
 
 FINE ART, 
 MINING, SURVEYING, ETC. 
 
 TO WHICH AEE ADDED 
 
 EXPLANATORY OBSERVATIONS 
 
 ON 
 NUMEROUS SUBJECTS CONNECTED WITH PRACTICAL ART AND SCIENCE. 
 
 SECOND EDITION, CORRECTED AND IMPROVED. 
 
 ' Or 
 
 EDITED AND PUBLISHED BY 
 
 JOHN WEALE, 59, HIGH HOLBORN. 
 1860. 
 
PRINTED BT 
 JOHN EDWARD TAYLOR, LITTLE QUEEN STREET, 
 
 LINCOLN'S INN FIELDS. 
 
 MRS. S. S. MONTAGUE 
 
PREFACE. 
 
 IT was intended that the contents of this \vork should be 
 comprised within the space of about one hundred and fifty 
 pages, and thus form a single volume of the series of * Rudi- 
 mentary Treatises ; ' but in the course of its compilation it 
 soon became apparent that such confined limits were wholly 
 inadequate to the admission of explanations of terms which, 
 although not immediately connected with the subjects men- 
 tioned in the title-page, were yet deemed essential to their 
 further amplification : its utility as a book of reference will 
 therefore, it is hoped, be found commensurate with its neces- 
 sarily increased extent. 
 
 Since the publication, in 1819, of Mr. Peter Nicholson's 
 elaborate 'Architectural Dictionary,' in two quarto volumes, 
 changes of vast import have occurred : the field of practical 
 science has been widely extended, and proportionately occu- 
 pied by a new generation of professional men and students ; 
 important advances have been made in the arts of design 
 and construction ; and the extended application of steam as 
 a motive power has not only produced an extraordinary de- 
 velopment of the means of internal communication, but 
 surmounted those impediments which considerations of space 
 and time formerly presented to the pursuits of men in quest 
 of business or pleasure, thus influencing, to a great extent, 
 
vi PREFACE. 
 
 the various operations by which the wants and luxuries of 
 civilized life are supplied. 
 
 In a ratio proportionate to the rapid extension of what 
 may be strictly termed practical knowledge has the study of 
 the more pleasurable sciences also progressed : archaeology, 
 architecture, civil and mechanical engineering, geology, etc., 
 have exercised a powerful and captivating influence, which has 
 gradually led to the incorporation of societies or associations 
 devoted to the cultivation and advancement of the several 
 branches of human knowledge; and hence has arisen an 
 extensive class of non-professional men, who, however duly 
 acquainted with scientific principles, may yet be anxious to 
 possess any easily available means of becoming familiar with 
 the nomenclature and the technical language necessarily 
 employed in a series of rudimentary treatises on the practical 
 arts and sciences. 
 
 Within the period already adverted to, much professional 
 taste and skill have been displayed in the erection of public 
 buildings, in the construction of engineering works of vast 
 magnitude and importance (both at home and abroad), and 
 in the invention of the improved machinery employed in the 
 arts and manufactures of the country. These and similar 
 causes have combined greatly to augment the ranks of a 
 meritorious and useful class of men, among whom, more 
 especially, new wants may be said to have been created, a 
 class which comprises no inconsiderable number of ingenious 
 operative engineers, artisans, etc. ; and to such this work 
 may become interesting and useful, however insufficient it may 
 prove to those already advanced in their professional pursuits. 
 
 Should, however, the paucity of information contained in 
 the following pages induce others more competent to the 
 task, and who have sufficient leisure for the purpose, to 
 devote their talents and time to the production of a more 
 
PREFACE. Vll 
 
 comprehensive and more valuable compilation, some share of 
 useful information will at least have been contributed to the 
 means of supplying the wants of an improving age. 
 
 The slender efforts here placed before the reader were ac- 
 complished, by the aid of the lamp, after the hours usually 
 devoted to the labours of business, and they are now, with 
 the most humble pretensions, submitted to public approval. 
 It has been well observed, that "the language of truth is 
 simple :" no attempt has here been made to trace the deriva- 
 tions of the scientific or technical terms which have been 
 adopted ; they are given and explained as generally written, 
 spoken, and understood at the present period, and care has been 
 taken to avoid surreptitious or unauthorized versions, with 
 the view of correctly guiding the student and the operative 
 workman in the onward path of knowledge. 
 
 Some analogous explanations and references may probably 
 appear, at a first glance, as superfluous, and to detract from 
 the merits of the work; but when it is considered how 
 numerous and varied, in the present age, are the ramifications 
 into which the employment of those engaged in the building 
 and constructive arts has been extended, and how earnestly 
 the searchers after technical terms and meanings must desire 
 the acquisition of a knowledge of what may not inaptly be 
 designated as a correct disposition of fine art, any unfavour- 
 able impression of this nature, hastily formed, will probably 
 be removed upon mature reflection, 
 
 In referring to the series of ' Rudimentary Scientific Works* 
 to which this ' Dictionary of Terms' will, it is presumed, be 
 deemed an appropriate Companion, it is proper to mention 
 that the first suggestion as to their publication emanated from 
 the late Major- General Sir William Reid, of the Corps of 
 Royal Engineers, and myself. Sir William kindly contributed, 
 as a commencement, Professor Fownes's ' Rudimentary Che- 
 
Vlll PREFACE. 
 
 mistry.' This elementary treatise, the first of the series, and 
 to which the recommendation of Sir William Reid was limited, 
 had been printed originally at his own expense, for the lau- 
 dable and special purpose of adding to the numerous educa- 
 tional and scientific works which he had already distributed 
 among different classes in the West India colonies. 
 
 To Major-General Portlock, R.E., E. B. Denison, Esq., Q.C., 
 and to Alan Stevenson, Esq., of Edinburgh, James Peake, Esq., 
 of Keyham (H.M.) Dockyard, Sir R. Macdonald Stephenson, 
 Charles Wye Williams, Esq., of Liverpool, William Bland, Esq., 
 of Hartlip, Kent, Hyde Clarke, Esq., David Gibbons, Esq., 
 Joseph Gwilt, Esq., and to others who have so liberally con- 
 tributed their aid in the production of the extensive treatises, 
 I have to acknowledge my obligations. 
 
 Of the First Edition 10,000 copies have been sold. The 
 present Edition, the second, has been revised with care, and, 
 it is hoped, will be found to be considerably improved. 
 
 JOHN WEALE. 
 
 59, High Holborn, 
 May, 1860. 
 
LIST OF THE WORKS WHICH HAVE BEEN CONSULTED IN 
 THE COMPILATION OF THIS DICTIONARY. 
 
 Adcock's Rules and Data for the Steam Engine, etc. 12mo. 1839. 
 
 Aide-Memoire to the Military Sciences. 3 vols. 8vo. 
 
 Architectural Papers. 4 vols. 4to. 
 
 Bartol's American Marine Boilers. 8vo. 1851. 
 
 Blashfield's Terra Cotta Vases, etc. 4to. 1857. 
 
 Britton's Architectural Dictionary. 4to. 1838. 
 
 Buchanan's Technological Dictionary. 12mo. 1849. 
 
 Practical Essays on Mill-work and on Machinery and Tools. 
 
 2 vols. 8vo. Edited by George Rennie, 1841. 
 Builder's (The) Dictionary. 2 vols. 4to. 1788. 
 Bury's Styles of Architecture. 12mo. 1855. 
 Calmet's Dictionary of the Bihle. 8vo. 1848. 
 Campbell's Text-Book of Inorganic Chemistry. 12mo. 1849. 
 Castell's Villas of the Ancients, fol. 1728. 
 Clegg's Essay on the Architecture of Machinery. 4to. 1842. 
 
 Manufacture and Distribution of Coal Gas. 4to. 1848. 
 
 Dana's Seaman's Vade Mecum. 12mo. 1856. 
 
 Dempsey's Practical Railway Engineer. 4to. 1855. 
 
 Dictionary of Painters, Sculptors, and Engravers. 8vo. 1810. 
 
 Divers Works of Early Masters. 2 vols. imp. folio. 1847. 
 
 Dobson's Student's Guide, by Garbett. 8vo. 1858-9. 
 
 Dodd's (Ralph) Observations on Water. 18mo. 1805. 
 
 Ensamples of Railway Making. 8vo. 1843. 
 
 Engineer and Contractor's Pocket-Book for 1859. 
 
 Engineering Papers. 6 vols. 4to. 
 
 Ewbank's Hydraulics and Machinery. 8vo. New York, 1849. 
 
 Fairbairn on Cast and Wrought Iron for Building Purposes. 8vo. 1858. 
 
 Fergusson's Rock-Cut Temples of India : plates folio, text 8vo. 1845. 
 
 Field's Chromatography. 8vo. 1841. 
 
LIST OF WORKS CONSULTED. 
 
 ^ Garbett (E. L.) on the Principles of Design in Architecture. 2 vols. 1852. 
 1 Glossary of Architecture. 3 vols. Oxford, Parker. 1845. 
 
 Greir's Mechanical Dictionary. 12mo. 1850. 
 
 Gregory's Mathematics for Practical Men : large 8vo. 1848. 
 
 Gwilt's (Joseph) Encyclopaedia of Architecture. 8vo. 1857. 
 
 -edition of Sir William Chambers's Civil Architecture. 
 
 2 vols. imperial 8vo. 1824. 
 
 Notitia Architectonica Italiana. 8vo. 1818. 
 
 Hamilton on Terms used in the Arts and Sciences. 12mo. 1825. 
 Hann's Theoretical and Practical Mechanics. 8vo. 1849. 
 Hann's etc. Theory and Practice of Bridges. 4 vols. in 3 : large 8vo. 1858. 
 Holzapffel's Turnery and Mechanical Manipulation. 3 vols. 8vo. 1848. 
 Homersham on Water Supply to Manchester and the adjacent Towns. 
 
 8vo. 1849. 
 
 Hunt's Tudor Architecture. 4to. 1830. 
 
 Button's Mathematical and Philosophical Dictionary. 2 vols. 4to. 1815. 
 Jamieson's (Dr.) Dictionary of Mechanical Science. 4to. 1827. 
 
 Mechanics for Practical Men. 8vo. 1830. 
 
 Leeds's Rudimentary Treatise on the Orders of Architecture. 12mo. 1855. 
 /Meason's Architecture of the Great Painters of Italy. 4to. 1828. 
 Meteorological Society's Transactions, vol. i. large 8vo. 1839. 
 National Encyclopaedia, by Mr. Charles Knight. 
 I/ Nicholson's Architectural Dictionary. 2 vols. 4to. 1819. 
 
 . Mechanical Exercises. 8vo. 1819. 
 
 Normand's Parallel of the Orders of Architecture, by Pugin : folio. 1829. 
 ^ Palladio's Architecture, with Notes by Inigo Jones. 2 vols. folio. 1742. 
 Pambour's Practical Treatise on Locomotive Engines. 8vo. 1840. 
 Papers connected with the Duties of the Corps of Royal Engineers. 10 vols. 
 
 4to. 1835-1849. 
 Papers and Practical Illustrations of Public Works, both British and 
 
 American, royal 8vo. 
 
 Pole on the Cornish Pumping Engine. 1 vol. 4to. folio plates. 1844. 
 Pryce's Treatise on Mines and Minerals : folio. 1773. 
 * Pugin's True Principles of Pointed or Christian Architecture. 4to. 1841. 
 r Apology for the Revival of Christian Architecture in England. 
 
 4to. 1843. 
 Reid (Major-General Sir Wm.) on the Law of Storms : large 8vo. 1850. 
 
 Variable Winds : crown 8vo. 1857. 
 
 Rennie's (Sir John) Harbours, Docks, and Coast Engineering. 2 vols. imp. 
 
 folio. 1855. 
 
 Repton's Theory and Practice of Landscape Architecture : large 4to. 1805. 
 Rich's Companion to the Greek Lexicon and Latin Dictionary. 8vo. 1849. 
 Smeaton's Reports. 4to. 1837. 
 
LIST OF WORKS CONSULTED. XI 
 
 Smith's Classical Dictionary: large 8vo. 1849. 
 
 Stephenson's (Robert) Report on the Atmospheric Railway System. 4 to. 
 1844. 
 
 Stuart's Antiquities of Athens. 4 vols. folio. 
 
 Taubert's Use of Field Artillery in Service, translated by Lieut. II. II. 
 Maxwell. 1856. 
 
 Templeton's Workshop Companion, 1858. 
 
 Thorman's Taunus Railway. 4to. 1846. 
 
 Tomlinson's Rudimentary Natural Philosophy. 12mo. 1856. 
 
 Transactions of the Institution of Civil Engineers. 3 vols. 4to. 1835-40. 
 
 Tredgoldon the Steam Engine. 2 vols. 4to. 1838-1849. 
 Strength of Cast Iron. 8vo. 1842. 
 
 Tredgold's Elementary Principles of Carpentry. 4to. 1856. 
 
 Vitruvius's Civil Architecture, by Wilkins : imperial 4to. 1812. 
 
 Watson's Account of Mines. 8vo. 1843. 
 
 Wicksteed's Experimental Inquiry into Cornish Engines. 4to. 1845. 
 
 Work on Cornish and Boulton and Watt Engines. 1846. 
 
 Wightwick's Hints to Young Architects. 8vo. 1846. 
 
 Williams (Chas. Wye) on Combustion. 2 vols. 12mo. 
 
 Willis's (Professor) Architectural Nomenclature. 4to. Cambridge. 
 
 System of Apparatus for the use of Lectures. 4to. 1841. 
 
 And lastly, The Dictionary of Architecture, by the Architectural Publication 
 Society, of which several Parts in folio have already appeared. To 
 this really learned and valuable work I am indebted, and acknow- 
 ledge with much pleasure and thankfulness the several extracts 
 made from it, and testify to its great utility to the profession at 
 large. 
 
ABB 
 
 ABERRATION. 
 
 ABS 
 
 modation of a fraternity under 
 ecclesiastical government. 
 
 Abbey gate-house, & lodge forwarders 
 or porters at the entrance of an 
 abbey edifice. 
 
 Abbot, the superior of a monastery of 
 monks erected into an abbey or 
 priory : there are various classes of 
 abbots, as mitred, crosiered, car- 
 dinal, regular, and commendatory 
 abbots. 
 
 Abbot's lodgings, in the early times of 
 English ecclesiastical architecture, 
 a complete house, with hall, chapel, 
 and every convenience for the resi- 
 dence of a spiritual baron. 
 
 Abbreviate, to contract a word in 
 writing or printing. 
 
 Abbreviations, characters or marks 
 over letters to signify either a word 
 or syllable. 
 
 Abel (John), an English architect of 
 considerable notoriety, died in 
 1674, aged 97 : built, during the 
 periods of James I. and Charles I., 
 the market-houses of Brecon, Here- 
 ford, Weobly, with its school- 
 house, Kingston, and Leominster, 
 and the timberwork of the church 
 at Abbeydore ; and being in Here- 
 ford when the Scots besieged it 
 in 1645, he constructed mills to 
 grind corn, which were of great use 
 to the besieged, and for which 
 Charles I. afterwards made him 
 one of his carpenters. 
 
 Abele-tree, a species of white poplar. 
 
 Aber, or Abber, the fall or emptying 
 a lesser water into a greater, as of 
 a brook into a river : hence several 
 towns situated on or near the 
 mouth of rivers generally derive 
 the first parts of their names. 
 
 Aberration, in astronomy, an appa- 
 rent motion of the celestial bodies 
 occasioned by the progressive mo- 
 tion of light and the earth's annual 
 motion in its orbit. 
 
 Aberration, in optics, the deviation 
 or dispersion of the rays of light 
 when reflected by a lens, by which 
 they are prevented from meeting 
 or uniting in the same point, called 
 the geometrical focus ; but spread 
 
 over a small span, they produce a 
 confusion of images. 
 
 Ablactation, in gardening, the method 
 of grafting. 
 
 Ablaqueation, the opening of the 
 ground around the roots of trees, 
 for the admission of the air. 
 
 Aboard, a nautical term, the inside of 
 a ship, or to go on board. 
 
 Abobe, unbaked bricks in Spain, used 
 for the erection of cottages in Cas- 
 tile and Leon. 
 
 About-ship, the situation of a ship 
 after she has tacked. 
 
 About-sledge, the largest hammer em- 
 ployed by smiths ; it is slung round 
 near the extremity of the handle, 
 and generally used by under work- 
 men, called hammer-men. 
 
 Abrasion, the effect produced by at- 
 trition or rubbing. 
 
 Abraum, a red clay, used in England 
 to give a red colour to new maho- 
 gany. 
 
 Abreast, as when two ships have their 
 sides parallel. 
 
 Abreuvoir, a watering-place. 
 
 Abreuvoir, in masonry, the interstice 
 or joint between two stones to be 
 filled up with mortar or cement. 
 
 Abscissa, a geometrical term for a 
 segment cut off from the straight 
 line by an ordinate to a curve. 
 
 Absis, or Apsis, the bowed or arched 
 roof of an oven, room, or house. 
 
 Absis, or Apsis, the ring or compass 
 of a wheel. 
 
 Absorbents, in chemistry, those earthy 
 substances capable of uniting, by 
 capillary attraction, a large pro- 
 portion of water : such are mag- 
 nesia, lime, and clay, when dry 
 and porous. 
 
 Absorbing-well, a shaft or boring for 
 removing either the excess of drain- 
 age-waters, or the foul waters pro- 
 duced by manufacturing purposes. 
 
 Absorption is the successive and inti- 
 mate penetration of a gas, or a 
 liquid, into any substance ; but fa- 
 miliarly, the taking up moisture, 
 in any material, by capillary at- 
 traction. 
 
 Abs thanes, a lower kind of nobility 
 
ABS 
 
 ABUSES. 
 
 ABU 
 
 formerly in Scotland, but now ex- 
 tinct. 
 
 Abstract (To), a term used by arti- 
 ficers and surveyors in arranging 
 and apportioning theh work, to 
 explain and price it. 
 
 Abstract mathematics, otherwise de- 
 nominated pure mathematics, that 
 branch of the science which treats 
 of simple properties, magnitude, 
 figure, or quantity, absolutely and 
 generally considered. 
 
 Abstraction and absorption of heat is 
 that process under which caloric, 
 or heat, passes from any body to 
 whatever surrounds it, or to any 
 conducting substance with which 
 it is in contact. 
 
 Absurd, a term used in demonstrating 
 converse propositions. 
 
 Abundant number, a number whose 
 aliquot parts, added together, make 
 a sum which is greater than the 
 number itself. 
 
 Abuses: "Architecture," says Palladio, 
 " being an imitatrix of Nature, de- 
 lights in that which is most conso- 
 nant with her prototype." Ancient 
 edifices were built with wood, trees 
 forming the columns ; and when 
 architects began to build with 
 stone, they made the columns to 
 imitate the trunks of trees, taper- 
 ing from their bases. Being thus 
 originally of wood, and therefore 
 liable to split when much loaded, 
 they bound them with rings at top 
 and bottom. Thus the bases and 
 capitals in the different orders 
 seem originally derived from these 
 bandages, though they are now 
 become essential ornaments. Thus 
 also in entablatures, the triglyphs, 
 modillions, and dentils represent 
 the ends of those beams and tim- 
 bers which are employed for the 
 support of the floors and roofs. If 
 therefore all these conditions be 
 duly considered, those practices in 
 building are highly to be repro- 
 bated which are in opposition to 
 that analogy which should exist 
 between the original and its imi- 
 tation, or which depart from Na- 
 
 ture and the simplicity observable 
 in all her works. 
 
 Consoles or cartouches, which 
 are of a scroll-like form, should 
 never be employed for the appa- 
 rent support of great weights, in 
 place of columns or pilasters ; nor 
 should they ever project from, or 
 spring out of cornices. 
 
 Pediments and frontispieces over 
 doors and windows, or elsewhere, 
 should on no account be broken or 
 disconnected in the middle ; for 
 the intention of these is to shelter 
 the parts below from the rain, and 
 this result is completely obviated 
 by such a practice. 
 
 The projecture of cornices, 
 though for the purpose of shelter- 
 ing buildings, should not be more 
 than in due proportion to their 
 height,whether or not accompanied 
 by columns ; for if too heavy, they 
 seem to threaten with danger those 
 who are under them ; and if too 
 small in projection, they do not 
 properly perform their office. 
 
 Again, those columns which are 
 feigned to be composed of several 
 pieces, by being jointed together 
 with rings, should be carefully 
 avoided, because the more solid 
 and strong the columns appear, the 
 better they seem to answer the pur- 
 pose for which they were erected, 
 which is securely to receive the 
 superincumbent loading. 
 
 There are many other abuses 
 which the authority of great mas- 
 ters may sanction, but not justify ; 
 and such will readily occur to the 
 student, and themselves point out 
 that they ought to be avoided. 
 'Abutment, the solid part of a pier 
 
 from which the arch springs. 
 Abutments, the extremities of a 
 bridge, by which it joins upon the 
 banks or sides of a river, etc. ; in 
 carpentry and joinery, the junc- 
 tions or meetings of two pieces of 
 timber, of which the fibres of the 
 one run perpendicular to the joint, 
 and those of the other parallel to 
 it. 
 
 B 2 
 
ABU 
 
 ACCESSES. 
 
 ACE 
 
 A'tuttah, the buttings or boundaries 
 of land. 
 
 Acacio, a heavy, durable wood, of the 
 red mahogany character, but darker 
 and plainer : it is highly esteemed 
 in ship-building. 
 
 Academia, in antiquity, a villa or plea- 
 sure-house in one of the suburbs 
 of Athens, where Plato and other 
 philosophers assembled. 
 
 Academician, a member of a society 
 or academy instituted for the cul- 
 tivation of the arts and sciences. 
 
 Academy-figure is a drawing or de- 
 sign, done after a model, with 
 
 j, crayon or pencil. 
 
 ^Acanthus, the plant Branca ursina, in 
 English bear 's-breech, the leaves of 
 which are imitated in decorating 
 the Corinthian and Composite ca- 
 pitals of columns. 
 
 Accelerated motion, a force acting in- 
 cessantly upon a body; called also a 
 constant or uniformly accelerating 
 force when the velocity increases 
 equally in equal times : the force of 
 gravity near the earth's surface is 
 of this kind ; it generates a velo- 
 city of 32 feet in each second of 
 time ; that is, a body, after falling 
 one second, acquires a velocity of 
 32 feet ; after falling two seconds, 
 it will acquire a velocity of 2 x 32 
 feet ; after three seconds, a velocity 
 of 3 x 32 feet, and so on. 
 
 Accelerating force, in physics, the 
 force which accelerates the motion 
 or velocity of bodies ; it is equal 
 to, or expressed by, the quotient 
 arising from the motion or absolute 
 force, divided by the mass or the 
 weight of the body moved. 
 
 Accelerative or retardative force, is 
 commonly understood to be that 
 which affects the velocity only, or 
 that by which the velocity is ac- 
 celerated or retarded; it is equal 
 or proportional to the motive force 
 directly, and to the mass or body 
 moved inversely. 
 
 Accesses, approaches or passages of 
 communication between the va- 
 rious apartments of a building, as 
 corridors. 
 
 Accessible, in surveying, a place -winch 
 admits of having a distance or 
 length of ground measured from 
 it ; or such a height or depth as 
 can be measured by the application 
 of a proper instrument. 
 
 Accessories, or accompaniments, in 
 painting, secondary objects to the 
 principal one in a picture, intro- 
 duced as explanatory and illus- 
 trative of the scene : sometimes 
 they are considered as solely con- 
 tributing to the general effect and 
 harmony of the piece. 
 
 Accidental point, in perspective, the 
 point in which a right line drawn 
 from the eye, parallel to another 
 right line, cuts the picture or per 
 spective plane. 
 
 Acclivity, the slope or steepness of a 
 line or plane inclined to the hori- 
 zon, taken upwards; in contra- 
 distinction to declivity, which is 
 taken downwards. 
 
 Accouplement, in carpentry, a tie or 
 brace, or the entire work when 
 framed. 
 
 Accretion, in physics, the growth or 
 increase of an organized body. 
 
 Accubitus, a room annexed to large 
 churches, in which the clergy oc- 
 casionally reposed. 
 
 Aceric acid, in chemistry, an acid 
 formed from the juice of the maple- 
 tree. 
 
 Acerra, in antiquity, an altar erected, 
 among the Romans, near the bed 
 of a person deceased, on which his 
 friends daily offered incense until 
 his burial. 
 
 Aces (a sea term), hooks for the 
 chains. 
 
 Acestides, the chimneys of furnaces 
 where brass was made ; they were 
 contrived to be narrow at top, on 
 purpose to receive and collect the 
 fumes of the melting metal, in or- 
 der that cadmia might be produced 
 in greater quantities. 
 
 Acetate of lead, sugar of lead, a 
 compound of acetic acid and 
 lead. 
 
 Acetate of potash, a compound of 
 acetic acid and potash, produced 
 
ACH 
 
 ACROTERIA. 
 
 ACT 
 
 by dissolving carbonate of potash 
 in distilled vinegar. 
 
 Achievement, the ensigns armorial of 
 a family. 
 
 Achleitner (Simon) was master of 
 the works at St. Stephen's, in 
 Vienna, 1481. 
 
 Achromatic, a term expressing ab- 
 sence of colour ; in optics, applied 
 to telescopes invented to remedy 
 aberrations and colours. 
 
 Achromatic, without colour, is ap- 
 plied in decorations to total absence 
 of colour : mere white and black, 
 or white and gold, may be consi- 
 dered in this sense achromatic. 
 
 Acids, in chemistry, are sour to the 
 taste, and convert vegetable blues 
 to a red colour ; they combine with 
 alkalies, earths, and metallic oxides, 
 and form, with them, the well- 
 known compounds named salts. 
 
 Acinose, a term applied to iron ore 
 found in masses, and of several 
 colours. 
 
 Acisculis, a small pick used by ma- 
 sons, having one end like that of 
 a hammer and the other pointed. 
 
 A-cock-bill, in navigation, the situ- 
 ation of the yards when they are 
 topped up at an angle with the 
 deck ; the situation of an anchor 
 when it hangs to the cat-head by 
 the ring only. 
 
 Acolyte, in the ancient church, a 
 person who trimmed the lamps, 
 prepared for the sacrament, etc. 
 
 Acorn, the seed of oak : imitations 
 of it are much used in architec- 
 ture, and it is sometimes intro- 
 duced instead of the egg in the 
 Roman ovolo. 
 
 Acoumeter, an instrument invented 
 by Itard for estimating the extent 
 of the sense of hearing. 
 
 Acoustics, the doctrine or theory of 
 sounds, consisting of diacoustics, 
 or direct sounds, and catacoustics, 
 or reflecting sounds. 
 
 Acre, a measure of land, containing, 
 by the ordinance for measuring 
 land in the time of Edward I., 160 
 perches or square poles of land ; 
 and as the statute length of a pole 
 
 is 5 yards, or 16 feet, the acre 
 contains 4840 square yards, or 
 43,560 square feet. The chain 
 with which land is now commonly 
 measured, invented by Gunter, is 
 4 poles, or 22 yards, in length; and 
 the acre is therefore just 10 square 
 chains ; and as a mile contains 
 1760 yards, or 80 chains, in length, 
 the square mile is equal to 640 
 acres. The acre, in surveying, is 
 divided into 4 roods, and the rood 
 into 4 perches. 
 
 Acrolithes, in sculpture, statues, the 
 extremities of which are formed of 
 stone. 
 
 Acropolis, a building strictly appli- 
 cable to a Greek city, and usually 
 erected upon a hill, rock, or some 
 natural elevation, and devoted to a 
 magnificent temple ; also a tower, 
 castle, or citadel. 
 
 Acrostolion, in ancient naval archi- 
 tecture, an ornament of the prow 
 or forecastle of a ship, chiefly of 
 war, most frequently circular or 
 spiral. 
 
 Acroteria, small pedestals at the 
 angles and vertex of a pediment : 
 the gate of the Agora at Athens is 
 the only instance in which they 
 appear in Grecian buildings. 
 
 Actinometer : Sir John Herschel, at 
 the third meeting of the British 
 Association, submitted an instru- 
 ment for measuring at any instant 
 the direct heating power of the 
 solar ray : it affords a dynamical 
 measure of the solar radiation, by 
 receiving a quantity of heat per 
 second, or any short space of time, 
 on a surface exposed to the sun. 
 In making observations with this 
 instrument, it should be freely ex- 
 posed in the shade for one minute, 
 and the variation read ; afterwards 
 expose it for the same time to the 
 solar action, and again note it ; and 
 lastly, repeat the experiment in the 
 shade : the mean of the two varia- 
 tions in the shade being subducted 
 from the variation in the sun, the 
 excess gives the dilatation per mi- 
 nute due to the sun's ravs the 
 
ACT 
 
 ADMEASUREMENT. 
 
 quantity subducted being the elfe*ct 
 of the other causes at the time. 
 
 Action, in painting or sculpture, the 
 posture, attitude, expressive of the 
 passion the painter or carver would 
 convey to the mind of a spectator. 
 
 Actus, a Roman measure of length, 
 equal to 120 Roman feet. 
 
 Acute angle, in geometry, less than a 
 right angle, and measured by less 
 than 90 or a quadrant of a circle. 
 
 Acute-angled cone, that in which the 
 opposite sides make an acute at the 
 vertex, or whose axis, in a right 
 cone, makes less than half a right 
 angle with the side. 
 
 Acute-angled section of a cone, an el- 
 lipsis made by a plane cutting both 
 sides of an acute-angled cone. 
 
 Acute-angled triangle, that in which 
 the three angles are all acute. 
 
 Adam (Wm.), an architect of Scot- 
 land, died about 1760, designed 
 and built several edifices. 
 
 Adam (John), of Edinburgh, son of 
 the above, executed several designs 
 in Scotland. 
 
 Adam (Robert), second son of Wil- 
 liam : he and his brother James 
 executed very many veiy splendid 
 buildings in England and Scotland, 
 more particularly in London, the 
 Adelphi, Portland-place, Lans- 
 downe-house, and other noble- 
 men's houses. 
 
 Mr. Weale purchased several 
 unpublished (and posthumous) 
 plates at the sale of the effects in 
 Albemarle-street in 1822, which 
 he published as a third or supple- 
 mentary volume to the two vo- 
 lumes sometime previously pub- 
 lished. 
 
 Adam (James), architect, also a son 
 of William Adam, died in Albe- 
 marle-street in 1794, was with his 
 brother Robert the intimate friend 
 of Clerisseau, Zucchi, and patrons 
 of other celebrated French and Ita- 
 lian artists. 
 
 Adam (William), architect, another 
 son of the same William, built 
 several houses in Whitehall, died 
 in 1822, aged 84. 
 
 Adamant, a very hard stone, used by 
 the ancients for cutting and polish- 
 ing other hard stones and glass. 
 
 Adeling, a title of honour given to 
 the children of princes among the 
 Anglo-Saxons. 
 
 Adhesion, the force with which differ- 
 ent bodies remain attached to each 
 other when brought into contact. 
 
 Adit, the passage or approach to a 
 house; applied also to the hori- 
 zontal shaft of a mine, driven for 
 the purposes of ventilating, water- 
 ing, or draining. 
 
 Adit-level, in mining, a horizontal 
 excavation through which the wa- 
 ter is drawn by the engine. 
 
 Adjacent angle, in geometry, an angle 
 immediately contiguous to another, 
 so that one side is common to both. 
 
 Adjutage (Ajutage}, or jet-d'eau, a 
 tube fitted to the aperture of a ves- 
 sel through which water is to be 
 played. 
 
 Admeasurement, the measuring or 
 finding the dimensions and quan- 
 tity of a thing by the application 
 of a standard or rule. 
 
 Admeasurement, a process in the art 
 of mensuration for measuring and 
 determining dimensions of work. 
 
 Adonia, a festival celebrated in ho- 
 nour of Aphrodite and Adonis in 
 most of the Grecian cities. 
 
 Adrift, the condition of a vessel 
 broken from her moorings. 
 
 Adytum, the most sacred place in the 
 heathen temples ; the Holy of Ho- 
 lies ; in Christian architecture, the 
 chancel or altar-end of a church. 
 
 Adze, an edged tool used to chip sur- 
 faces in a horizontal direction ; the 
 axe being employed to chop mate- 
 rials in vertical positions. 
 
 sEbrechts (H.) was with Louis Ger- 
 brandt and Klas Huygens, in 1499, 
 to build the town-hall at Gonda, 
 in Holland. 
 
 JEcclesiolo, in Domesday Book, a 
 chapel subordinate to the mother 
 church. 
 
 JEdes, an inferior kind of temple ; in 
 Christian architecture, a chapel ; 
 also sometimes applied to a house. 
 
MDl 
 
 .EGINA MARBLES. 
 
 jEdicula, a small chapel, house, or 
 building of any kind; not unfre- 
 quently applied to the niches of 
 tabernacles in a wall which held 
 statues of the lares or penates. 
 
 JEgina marbles: C. R. Cockerell, Esq., 
 visited Athens with Mr. Foster in 
 1811. In examining the temples 
 of Athens, with their lamented 
 friend and companion, the Baron 
 Haller, some details, of singular 
 interest and novelty, induced them 
 to form the project of excavating 
 the Temple of Jupiter at ^Egina, 
 for the purpose of ascertaining how 
 far these might be found common 
 to other remains of Grecian archi- 
 tecture, as well as for the general 
 object of advancing their stu- 
 dies. 
 
 The jEginetan statues furnish 
 the only illustrations of the heroic 
 costume and armour, as described 
 by Homer, ^Eschylus, and the ear- 
 liest Grecian writers ; and the great 
 nicety of execution in the smallest 
 details corresponds perfectly with 
 the exactness which the poets have 
 observed in their description : a 
 minute and scrupulous attention 
 is paid to each tie and fastening ; 
 and as if the whole had been of- 
 fered to the severest scrutiny, the 
 parts never seen were equally fur- 
 nished with exact resemblance of 
 each particular detail in the most 
 ancient coins of Corinth, Sybaris, 
 Posidonia, and the earliest Greek 
 cities of Italy, as well as of Ionia, 
 which were much earlier proficients 
 in arts than those of Greece Pro- 
 per ; and in the vases of the most 
 archaic style (commonly in black 
 on a red ground) we trace the cha- 
 racter which is developed and ex- 
 plained in these statues. 
 
 The magnificent statue of Mi- 
 nerva, who, by her action, seems 
 from Olympus to have just alighted 
 to animate the combat by her pre- 
 sence, we have the most antique 
 costume hitherto known to us. 
 The form of the ^Egis is singular, 
 nor have we seen it before in 
 
 sculpture, surrounded with the 
 tassels, the noise of which was 
 said to have dismayed her oppo- 
 nents : we know such a sort of 
 appendage to have been in much 
 earlier use than the more usual 
 one of the serpents. These were 
 undoubtedly of brass, or some me- 
 tal, which has disappeared; they 
 were fastened by rivets of lead, 
 most of which still remained. The 
 holes by which the Gorgon's head 
 was attached to her breast were 
 evident, and the whole of the ./Egis 
 was painted with scales in en- 
 caustic; they could not however 
 be discovered. 
 
 The lion's head attached to the 
 extreme tile of this temple was 
 found perfect, and in the blocking, 
 which carries the Chimaera, was a 
 sinking, corresponding with the 
 thickness of the plinth, to which 
 the legs were attached. 
 
 The whole of the ornaments in- 
 dicated on the several members of 
 the cornice were painted on the 
 marble in encaustic; as are the 
 extreme tiles, forming the upper 
 moulding of the pediment ; and on 
 the stone of which the whole tem- 
 ple was constructed, is a thin coat 
 or varnish of very fine and hard 
 plaster. 
 
 jfigricanes, a name given to rams' 
 heads when sculptured on friezes, 
 altars, etc. 
 
 jfigyptilla, a species of Egyptian or- 
 nament. 
 
 JEmasia, a fence, or fence-wall. 
 
 JEolipile, in hydraulics, an instrument 
 consisting of a hollow metallic ball 
 with a slender neck or pipe pro- 
 ceeding from it, which, being filled 
 with water, produces a violent blast 
 of wind. 
 
 JEolus, a small portable machine for 
 refreshing and changing the air of 
 apartments. 
 
 JEolus (in mythology, the god of 
 winds), the name of a ventilator, 
 or a machine used to extract foul 
 air out of rooms. 
 
 , a treasury among the Ro- 
 
AER 
 
 ESTHETICS. 
 
 AGN 
 
 mans ; the place where public ^mo- 
 ney was deposited. 
 
 Serial perspective, the relative appa- 
 rent recession of objects from the 
 foreground, owing to the quantity 
 of air interposed between them and 
 the spectator. 
 
 ;Ero, according to Vitruvius, a bas- 
 ket to carry earth in, used by the 
 Romans. 
 
 Aero-dynamics, the science relating 
 to the active powers or forces of 
 gaseous fluids. 
 
 Aerology, the doctrine or science of 
 the air. 
 
 Aerometer, an instrument contrived 
 to ascertain the mean bulk of 
 gases. 
 
 Aerometry, the science of measuring 
 the air, its powers and proper- 
 ties. 
 
 Aeronautics, the art of sailing or 
 floating in the air. 
 
 Aerostatics, the doctrine of the 
 weight, pressure, and balance of 
 the air and atmosphere. 
 
 JErugo, rust, more especially that of 
 copper, verdigris. 
 
 ^Esthetics, the power of perception by 
 means of the senses : the word im- 
 plies the perception and the study 
 of those qualities which constitute 
 the beautiful and artistic, and form 
 the finer essence of all productions 
 of fine art ; it carries with it, there- 
 fore, a more exact and philosophic 
 meaning than the word ' taste :' in 
 its adjective form, in which it more 
 frequently occurs, it is particularly 
 useful, as no adequate epithet can 
 be substituted for it. Thus we speak 
 of the 'aesthetic sense,' of 'aesthetic 
 feeling/ or ' study,' or ' principles,' 
 etc. ; but we cannot correctly say, 
 the 'tasteful sense/ or 'tasteful 
 study.' 
 
 Mstuarium, a description of the an- 
 cient baths, to the flue from hypo- 
 caustum or stove to chambers. 
 
 JEsymnium, a building in Megara ; 
 so called from ^Esymnius, its 
 founder, who erected that edifice, 
 which consisted of a council-hall 
 round t?ie tomb of his countrymen 
 
 who died in battle against the Per- 
 sians. 
 
 JEthousa, the portico on the sunny 
 side of the court of a Greek dwell- 
 ing. 
 
 Aetoma, a pediment, or the tympanum 
 of a pediment. 
 
 Affection, in painting, the represen- 
 tation of any passions, whereby they 
 appear to be animated, and swell 
 to the sight. 
 
 Affections in general: 1, character, 
 qualities, disposition, nature, spirit, 
 temper, temperament, idiosyncrasy, 
 cast, or frame of mind or soul ; 2, 
 personal affections ; 3, prospective 
 affections ; 4, contemplative affec- 
 tions ; 5, extrinsic affections, so- 
 cial affections, diffusive sympathe- 
 tic affections, special sympathetic 
 affections, retrospective sympathe- 
 tic affections, moral obligations, 
 moral sentiments, moral practice, 
 institutions, religious affections, 
 doctrines, sentiments, acts of reli- 
 gion, religious institutions. 
 
 Affinity, in chemistry, the power by 
 which the ultimate particles of 
 matter are made to unite, and kept 
 united. 
 
 Afflux, a flow of electric matter to a 
 globe and conductor, in opposition 
 to efflux, from them. 
 
 After, in ship-building, implies a con- 
 nection, as belonging to the after- 
 body, after-timber, etc. 
 ^ Ay alma, a sculptural ornament or 
 image. 
 
 Ager, a Roman acre of land. 
 
 Agger, a heap or mound of any kind, 
 formed of stone, wood, or earth. 
 
 Agglutination, the cohesion of bodies. 
 
 Aggregation, in chemistry, the col- 
 lection of bodies, solid, fluid, or 
 gaseous. 
 
 Agiasterium, the sanctuary, which is 
 the basilicae of the Latin Church. 
 
 Agnolo (B. I)'), born in 1459, ex- 
 celled in inlaid works, and exe- 
 cuted at Florence, besides some 
 coffers in walnut-wood, a large 
 figure-frame, described by Vasari : 
 he was also the most celebrated 
 carver of his time. 
 
 8 
 
AGN 
 
 AIR-PUMP. 
 
 AIR 
 
 Agnolo (D. D'), a son of the pre- 
 ceding, Baccio : was also a wood- 
 carver as well as an architect. 
 
 Agnolo (G. D') another son of Baccio : 
 besides wood-carving, he gave more 
 attention to architecture. 
 
 Ayora, a place of public assembly, in 
 a Greek city, for the transaction 
 of all public business; a market- 
 place. 
 
 -'Agrafe, a French term used by buil- 
 ders for small cramps employed in 
 fixing chimney-pieces, etc. 
 
 Ayrippa (Camillus), a distinguished 
 Milanese architect of the sixteenth 
 century. 
 
 * Aguilla, an obelisk, or the spire of a 
 church-tower. 
 
 A-hull, the condition of a vessel when 
 she has all her sails furled, and her 
 helm lashed a-lee. 
 
 Aile, the wing, the inward portico, 
 on each side of a church or other 
 large building, supported by pil- 
 lars within. 
 
 Air-brick, an iron box used in walls, 
 and usually made to the size of a 
 brick, but with one of its faces 
 formed into a grating. 
 
 Air-casing, the sheet-iron casing 
 which surrounds the base of the 
 chimney of a steam-vessel, to pre- 
 vent too great a transmission of 
 heat to the deck. 
 
 Air-drains, cavities between the ex- 
 ternal walls of a building, protected 
 by a wall towards the earth, which 
 is thus prevented from causing 
 dampness. 
 
 Air-escape, a contrivance for letting 
 off the air from water-pipes. 
 
 Air-holes, those made for admitting 
 air to ventilate apartments. 
 
 Air-machine, in raining, the apparatus 
 used for forcing purer air into or 
 withdrawing foul air from parts 
 badly ventilated. 
 
 Air-pipes, in mining, tubes or pipes 
 of iron or wood, for ventilating 
 under ground, or for the convey- 
 ance of fresh air into levels having 
 but one communication with the 
 atmosphere, and no current of air : 
 also used for clearing foul air from 
 
 the holds of ships or other close 
 places. 
 
 Air-pump, a pneumatic instrument, 
 by means of which the air is ex- 
 hausted out of the proper vessels : 
 its effects are produced by the elas- 
 ticity of the air; and as at each 
 stroke of the pump only a part of 
 the remaining air is withdrawn, an 
 absolute vacuum cannot be ob- 
 tained, although so near an ap- 
 proximation to it may be had as 
 to remove the general effects of 
 the atmosphere. In steam-engines, 
 the proportion of the air-pump, as 
 given by Watt, is usually about 
 two-thirds of the diameter of the 
 cylinder, when the length of the 
 stroke of the air-bucket is half the 
 length of the stroke of the steam- 
 piston. The area of the passages 
 between the condenser and the 
 air-pump should never be less than 
 one-fourth of the area of the air- 
 pump. The apertures through the 
 air-bucket should have the same 
 proportion ; and, if convenient, the 
 discharging flap or valve should be 
 made larger. The capacity of the 
 condenser should at least be equal 
 to that of the air-pump ; but, when 
 convenience will admit of it, the 
 larger it is the better. 
 
 Air-pump bucket, an open piston, 
 with valves on the upper surface, 
 opening upwards, so as to admit 
 the air and water in the down- 
 stroke, and lift it with the up- 
 stroke of the pump. 
 
 Air-pump rod, the rod for connecting 
 the bucket to the beam. 
 
 Air-shaft, in mining, a passage made 
 for the air by digging. 
 
 Air-tint, in painting, the tint by 
 which the distant parts of a land- 
 scape are rendered more distinct, 
 or sometimes giving a misty appear- 
 ance to the whole : it is generally 
 compounded of a blue-grey, occa- 
 sionally approaching to purple. 
 
 Air-trap, a trap immersed in water, 
 to prevent foul air arising from 
 sewers or drains. 
 
 Air-valve, applied to steam boilers 
 
 B 3 
 
AIR 
 
 AIR-VESSEL. 
 
 ALG 
 
 for the purpose of preventing the 
 formation of a vacuum when the 
 steam is condensing in the boiler. 
 
 Air-vessel, the closed cylinder con- 
 nected to the discharge-pipe of a 
 force-pump, and by the action of 
 which the water ejected by the pis- 
 ton or plunger of the pump enters 
 the cylinder and compresses the air 
 within ; it acts as a spring during 
 the return stroke, and thus renders 
 the stream constant ; also a cham- 
 ber containing air, attached to 
 pumps and other water-engines, for 
 the purpose of making the dis- 
 charge constant when the supply 
 is intermittent. 
 
 Aisle, the side-passage or division of 
 a church, partially separated from 
 the nave and choir by columns or 
 piers. 
 
 Aitre, a hearth or chimney. 
 
 Ajambe, the French term for a win- 
 dow : it differs from the usual 
 French window in having four or 
 more casements, with separate 
 hinges and fastenings complete, 
 instead of two upright ones, which 
 they generally have. 
 
 Alabaster, a species of gypsum, a mi- 
 neral substance, chemically termed 
 sulphate of lime; also a box or 
 vase for holding perfumes and oint- 
 ments, so called because originally 
 made of alabaster, and for which 
 the variety called onyx-alabaster 
 was usually employed. 
 
 Alba, a beacon or lighthouse. 
 
 Albarium, white-wash ; according to 
 Pliny and Vitruvius, a white stucco 
 or plaster, made of a pure kind of 
 lime burned from marble, and used 
 to spread over the roofs of houses. 
 
 Albarium opus, according to Vitru- 
 vius, a species of stuccowork. 
 
 Alberti (Leone Battista), the son of 
 a noble Florentine, born at Genoa 
 in 1406 : an architect of some ce- 
 lebrity, and an author on the sub- 
 jects of architecture and paint- 
 ing. 
 
 Albertolli (G.), the son of an archi- 
 tect, born at Bedana in 1742 : was 
 an architect of repute, and pub- 
 
 blished some works on ornament 
 of refined taste. 
 
 Alcha, a cellar, pantry, or an apart- 
 ment for the reception of drinking 
 vessels. 
 
 Alchemist, one skilled in the art of 
 alchemy or chemistry. 
 
 Alchemy, that branch of chemistry 
 which presumes the transmutation 
 of metals : Lord Bacon calls it the 
 art of distilling or drawing quint- 
 essences out of metals by fire. 
 
 Alcohol, in chemistry, a pure spirit. 
 
 Alcoholometer, an instrument for as- 
 certaining the strength of spirits. 
 
 Alcorans, in oriental architecture, 
 high slender towers attached to 
 mosques, in which the Koran is 
 read. 
 
 Alcove, a recess in a chamber, or a 
 recess separated from other parts 
 of the room by columns, antae, and 
 balusters. 
 
 Alder, a wood formerly much used. 
 The common alder seldom exceeds 
 40 feet in height, is very durable 
 under water, and was used for the 
 piles of the Rialto at Venice, the 
 buildings at Ravenna, etc. : it was 
 formerly much used for pipes, 
 pumps, and sluices. 
 
 Aldrich (Henry), dean of Christ 
 Church, Oxford, born in 1647 : he 
 was distinguished for his architec- 
 tural attainments, and published a 
 work on its elements. 
 
 Aleaceria, a palace, castle, or other 
 large edifice. 
 
 Aleatorium, an apartment in a Roman 
 house appropriated to the use of 
 persons playing with dice. 
 
 A-lee, a term used to denote the posi- 
 tion of the helm when it is put in 
 the opposite direction from that in 
 which the wind blows. 
 
 Alembic, in chemistry, a vessel used 
 in distillation. 
 
 Aleois, loopholes in the walls of a cas- 
 tle or fortification, through which 
 arrows may be discharged. 
 
 Algebra, literal arithmetic, or the 
 science by which quantity, and the 
 operations of quantity, are ex- 
 pressed by conventional symbols. 
 
 10 
 
ALH 
 
 ALTAR. 
 
 ALT 
 
 Alhambra, in Saracenic architecture, 
 the royal palace of the kings of 
 Granada. 
 
 Alien priories, cells or small religious 
 houses erected in different coun- 
 tries, and distinguished as alien 
 from their dependence on large 
 foreign monasteries. 
 
 Alipterion, in ancient Rome, a room 
 wherein bathers anointed them- 
 selves. 
 
 Aliquot part, such part of a number 
 as will exactly divide it without a 
 remainder ; a part as, being taken 
 or repeated a certain number of 
 times, exactly makes up or is equal 
 to the whole : thus 1 is an aliquot 
 part of 6, or any other whole num- 
 ber. 
 
 Alkalimeter, an instrument for mea- 
 suring and determining the quan- 
 tity and strength of alkalies. 
 
 Allette, used to express a small wing 
 of a building; also applied to a 
 pilaster or buttress. 
 
 Alley, a passage from one part of a 
 building to another ; a passage or 
 court with houses. 
 
 Alligation, one of the rules of arith- 
 metic, by which are resolved ques- 
 tions which relate to the com- 
 pounding or mixing together of 
 divers simples or ingredients. 
 
 Allorium, a piazza, corridor, or co- 
 vered way in the flank of a building. 
 
 Alloy, baser metal, commonly mixed 
 with the precious metals. 
 
 Alluminate (To), in painting, to wash 
 prints with alum-water, to keep 
 the colours from sinking or run- 
 ning. 
 
 Alluminate (To), to enlighten; to 
 give grace, light, and ornament. 
 
 Alluvium, the debris occasioned by 
 causes still in operation, as deposits 
 left by the action of rivers, floods, 
 and torrents. 
 
 Almacantar, lines parallel to the ho- 
 rizon, and conceived to pass through 
 every degree of the meridian. 
 
 Almasia, in old records, the archives 
 of a church ; a library. 
 
 Almehrab, a niche in the mosques of 
 the Arabs, for praying. 
 
 11 
 
 Almond-furnace, a furnace used by 
 refiners, and called a sweep, for 
 separating all sorts of metals from 
 cinders, etc. 
 
 Almond-tree, a hard, heavy, oily, or 
 resinous kind of wood, somewhat 
 pliable. 
 
 Almonry, a room or place where alms 
 were formerly distributed to the 
 poor. 
 
 Almshouse, a house for the reception 
 and support of the poor. 
 
 Aloof, in navigation, to keep the ship 
 near the wind when sailing upon a 
 quarter wind. 
 
 Alquifore, lead ore found in Cornwall, 
 and used by potters to green-var- 
 nish their wares. 
 
 Alrunae, small images carved out of 
 roots of trees, and anciently held in 
 much veneration by the northern 
 nations. 
 
 Altar, an elevated table of either 
 stone, marble, or wood, dedicated 
 to the ceremonies of religious wor- 
 ship. " And Noah builded an altar 
 unto the Lord ; and took of every 
 clean beast, and of every clean 
 fowl, and offered burnt-offerings 
 on the altar." 
 
 Altar-piece, the ornamental sculpture 
 or painting behind the altar in a 
 Christian church. 
 
 Altar-screen, the back of an altar, or 
 the partition by which the choir is 
 separated from the presbytery and 
 lady-chapel. 
 
 Altars, among the Greeks, according 
 to Wilkins's ' Vitruvius,' faced the 
 east, and were placed lower than 
 the statues arranged about the cella, 
 in order that those who offered up 
 prayers and sacrifices might know, 
 from their different heights, to 
 what particular deities the several 
 altars were consecrated. 
 
 Altare chori, a reading-desk in a 
 church. 
 
 Altare farum, the lustre, chandelier, 
 or cresset, suspended over an al- 
 tar. 
 
 Altimetry, the art of taking or mea- 
 suring altitudes or heights. 
 
 Altitude, of a figure, the length of a 
 
A.ND 
 
 ANNULAR ENGINE. 
 
 ANN 
 
 Andron, an apartment, cloister, jor 
 gallery, assigned to the male part 
 of a monastic establishment ; ap- 
 plied also to the space in a church 
 by which the men were separated 
 from the women. 
 Anemography, a description of the 
 
 winds. 
 
 Anemometer, an instrument for mea- 
 suring the force of the wind. 
 Anemoscope, a machine to denote 
 the changes of the wind or wea- 
 ther. 
 
 Angiportum, among the ancients, a 
 narrow lane between two rows of 
 houses. 
 
 Angle, in geometry, the mutual in- 
 clination of two lines meeting in a 
 point. 
 
 Angle-bar, in joinery, the upright bar 
 at the angle of a polygonal win- 
 dow. 
 
 Angle-bead, a vertical bead, com- 
 monly of wood, fixed to an exte- 
 rior angle, and flush with the sur- 
 face of the plaster, etc. of rooms, 
 arches, etc. 
 
 Angle-brace, in carpentry, timber 
 fixed to the two extremities of a 
 piece of quadrangular framing, 
 making it to partake of the form 
 of an octagon. 
 
 Angle-bracket, a bracket placed in 
 the vertex of an angle, and not at 
 right angles with the sides. 
 Angle-capital, used in Ionic capitals 
 to the flank columns which have 
 their volutes placed at an angle of 
 45 with the planes of the front 
 and returning friezes. 
 Angle-float, in plastering, a float made 
 to any internal angle to the planes 
 of both sides of a room. 
 Angle-modillion, a modillion placed in 
 a direction parallel to a diagonal 
 drawn through a cornice at its 
 mitring. 
 
 Angle-staff', vertical head, generally 
 of wood, fixed to exterior angles 
 of a building flush with the service 
 of the plaster. 
 
 Angle of application, the angle which 
 the line of direction of a power 
 gives the lever it acts upon. 
 
 Angle of inclination, the angle an in- 
 clined plane makes with the horizon. 
 
 Angle of traction, the angle which 
 the direction of a power makes 
 with the inclined plane. 
 
 Angular modillions, those which are 
 placed at the return of a cornice 
 in the diagonal vertical plane, pass- 
 ing through the angle or mitre of 
 the cornice. 
 
 Angular perspective, a term applied 
 to the horizontal lines, both of the 
 front and end of a building, con- 
 verging to vanishing points, and 
 terminating in the horizon ; it is 
 sometimes called oblique perspec- 
 tive. 
 
 Anlace, a falchion or sword, shaped 
 like a scythe. 
 
 Annealing, the process of softening 
 and restoring the malleability of 
 metals, by heating and allowing 
 them to cool very slowly ; and by 
 which means glass, cast-iron, and 
 steel, may be united to other sub- 
 stances. 
 
 Annatto, in chemistry, a reddish-yel- 
 low vegetable dye, obtained from 
 the seeds of the Bixa Orellana, and 
 used for colouring cheese. 
 Annicut, the Hindostanee term for a 
 weir or dam : it is a stoppage built 
 out in a river from a bank, as a 
 pier or breakwater, and made use 
 of in the Indian rivers to intercept 
 the current of the stream, and di- 
 vert a portion of its waters into 
 channels or reservoirs for agricul- 
 tural purposes. 
 
 Annular engine, a direct-action ma- 
 rine engine, having two concentric 
 cylinders ; the annular space is 
 fitted with a piston which is at- 
 tached to a T-shaped cross-head by 
 two piston-rods : the cross-head is 
 formed by two plates with a space 
 between for the connecting-rod to 
 vibrate, and the lower end slides 
 within the inner cylinder, and is 
 connected to the crank. This ar- 
 rangement has been patented by 
 Messrs. Maudslay. 
 
 Annular vault, a vaulted roof sup- 
 ported on circular walls. 
 
 14 
 
ANN 
 
 ANTEFIX^E. 
 
 ANT 
 
 ^Annulated columns, those clustered 
 together or joined by rings or 
 bands. 
 
 Annulet, in architecture, a small 
 square member in the Doric capi- 
 tal ; also the name of a small flat 
 moulding. 
 
 Anston, a parish in Yorkshire from 
 whence the stone used for the 
 Houses of Parliament have been 
 brought. 
 
 Antarala, the inner vestibule of a 
 Hindoo temple. 
 
 Antee, square pilasters terminating 
 the walls of a temple : when a 
 temple had no portico in front, two 
 columns were made to intervene 
 between the anta?, and the aspect 
 of the temple was said to be in 
 antis. 
 
 Antechamber, a room or passage to 
 an inner chamber, for the accom- 
 modation of servants and persons 
 in waiting. 
 
 Ante-capitulum, part of a cloister be- 
 fore the door of a chapter-house. 
 vAntefixce. (by some called Greek tiles), 
 upright ornamental blocks placed 
 at intervals on the cornice along 
 the side of a roof, to conceal or 
 rather terminate the ridges formed 
 by the overlapping of the roof-tiles ; 
 also heads of lions, etc., for water- 
 spouts below the eaves of temples. 
 
 Antemural, a term applied to the 
 outward wall of a castle ; or that 
 which separates a presbytery from 
 a choir ; also to a barbican en- 
 trance before a castle. 
 
 Antepagmenta, or Antepagmenlum, 
 the jamb of a door-case. 
 
 Ante-parallels, in geometry, lines 
 which make equal angles with two 
 other lines, but in a contrary direc- 
 tion. 
 
 Ante-portico, a term sometimes used 
 to denote an outer porch or vesti- 
 bule ; the propylaeum in classic 
 architecture. 
 
 Anterides, buttresses for strengthen- 
 ing walls. 
 
 Ante- solarium, a balcony facing the 
 sun. 
 
 Ante-venna, an awning or projecting 
 
 roof of woodwork ; a wooden or 
 pent-house before a shop. 
 
 Anthepsa, a Grecian vessel used for 
 boiling water or keeping it hot ; a 
 cooking utensil. 
 
 Anthracite, a coal not bituminous, 
 found principally in South Wales 
 and in the United States. 
 
 dntics, in architecture, figures of men, 
 beasts, etc., placed as ornaments to 
 buildings. 
 
 Anticum, a porch before a door. 
 
 Antilia, an ancient machine similar 
 to the modern pump. 
 
 Antimensium, a portable altar or con- 
 secrated table, used as a substitute 
 for a proper altar. 
 
 Antimeter, an optical instrument for 
 measuring angles. 
 
 Antimony, a metal usually found in a 
 crude state combined with sulphur, 
 of a bluish-white colour, crystal- 
 line texture, brittle, and easily pul- 
 verized : it does not oxidate at 
 ordinary temperatures in the air, 
 but, when heated, it burns with a 
 light flame, producing the oxide ; 
 it fuses at 800, and volatilizes at 
 a white heat. 
 
 Antimony yellow, a preparation of 
 antimony, of a deeper colour than 
 Naples yellow, and similar in its 
 properties : it is principally used 
 in enamel and porcelain painting, 
 and is very various in tint ; that 
 of a bright colour is not affected 
 by foul air, although blackened by 
 sugar of lead. 
 
 * Antipagments, ornaments in carved 
 work on the architrave, jambs, 
 posts, or puncheons of doors. 
 
 Antiquarium, a repository for antique 
 monuments. 
 
 Antoine (J. D.), born in Paris in 
 1733: became in after-years an 
 architect of a high position ; built 
 several noble edifices, in Paris 
 principally; died in 1807. 
 
 Antrellum, a small grave or grotto ; 
 also a small temple. 
 
 Antrum, an early temple for Christian 
 worship. 
 
 Antrum tumbale, a sepulchral cave or 
 grotto. 
 
 15 
 
ANT 
 
 APPIAN WAY. 
 
 APP 
 
 Antwerp blue, Hght- coloured, and 
 somewhat brighter than Prussian 
 blue, or ferro-prussiate of alumine, 
 having more of the terrene basis, 
 but all the other qualities of that 
 pigment, except its extreme depth. 
 Haarlem blue is a similar pigment. 
 
 Antwerp brown, a preparation of as- 
 phaltum, ground in strong drying 
 oil, by which it becomes less liable 
 to crack. 
 
 Anvil, a large block of iron with a 
 very hard, smooth, horizontal sur- 
 face on the top, in which there is 
 a hole at one end, for the purpose 
 of inserting various tools, and a 
 strong steel chisel, on which a piece 
 of iron may be laid, and cut through 
 by a blow with a hammer. 
 
 A-pecJc, a nautical term implying that 
 the cable is hove taut, so as to bring 
 the vessel nearly over her anchor : 
 the yards are a-peek when they are 
 topped up by contrary lifts. 
 * Aperture, an opening in a wall, door- 
 way, or window. 
 
 Apex, the top or highest point of a 
 cone, mountain, pyramid, spire, 
 roof, etc. 
 
 Apiary, a place where bees are kept. 
 
 Aplome, a mineral of a deep orange- 
 colour. 
 
 Aplustre, in early naval architecture, 
 a carved tablet fixed on the extre- 
 mity of a ship's head, or ensign. 
 
 Apodyterium, a dressing-room or 
 anteroom to a bath in Roman vil- 
 las, contiguous to the laconicum. 
 
 Apophyge, in architecture, that part 
 of a column between the upper 
 fillet of the base and the cylindrical 
 shaft, which is usually curved into 
 it by a concave sweep or inverted 
 cavetto. 
 
 Apostles (the) of Jesus Christ were his 
 chief disciples, whom he invested 
 with his authority, filled with his 
 spirit, and instructed particularly 
 in his doctrines and services : they 
 were chosen to raise the edifice of 
 his Church, and, after his resurrec- 
 tion, sent into all the world, com- 
 missioned to preach, to baptize, and 
 to work miracles. The names of 
 
 16 
 
 the twelve were: 1, Peter; 2, An- 
 drew; 3, John; 4, Philip; 5, James, 
 major; 6, Bartholomew; 7, Thomas; 
 8, Matthew; 9, Simon; 10, Jude; 
 11, James, minor ; 12, Judas Isca- 
 riot. The last betrayed his mas- 
 ter, and having hanged himself, 
 Matthias was chosen in his place. 
 
 Apostles (the), in the tables of sym- 
 bols of the early ages, were repre- 
 sented by twelve sheep or lambs 
 issuing from Bethlehem and Jeru- 
 salem, cities of Christ's birth and 
 death. 
 
 Apotheca, a place in the upper part 
 of the house, in which the Romans 
 frequently placed their wines in 
 earthen amphorae ; also an apothe- 
 cary's shop, a cabinet, storehouse, 
 etc. 
 
 Apothesis, a recess on the south side 
 of the chancel of a church, fitted 
 up with shelves for books, vest- 
 ments, etc. 
 
 Apparatus, a term denoting a com- 
 plete set of instruments belonging 
 to an artist or a mechanist. 
 
 Appian way, a celebrated road lead- 
 ing from Rome to Brundusium : so 
 named from Appius Claudius. 
 
 Appii forum, the forum built by Ap- 
 pius, the Roman consul, about fifty 
 miles distant from Rome, near the 
 modern town of Piperno, on the 
 way to Naples. The uses to which 
 the Romans applied the forum were 
 so various, that it is not easy to as- 
 certain the nature of the building. 
 It might have been a place for the 
 distribution of justice, or for hold- 
 ing a market. The Three Ta- 
 verns' were nearer to Rome than 
 the Appii Forum, as Cicero inti- 
 mates, who, in going from Rome, 
 a little before he came to the fo- 
 rum of Appius, arrived at the Three 
 Taverns ; so that probably the chief 
 number of Christians waited for the 
 Apostle Paul at a place of refresh- 
 ment, while some of their number 
 went forward to meet him, and 
 respecfully to acquaint him with 
 their expectation of seeing him 
 among them. 
 
APP 
 
 ARCADE. 
 
 ARC 
 
 Apple-tree, a wood generally hard and 
 close, and of reddish-brown tints, 
 used commonly in Tunbridge tur- 
 nery, etc. 
 
 Apricot-tree, a native wood of Arme- 
 nia, used by the French in turnery. 
 v Apron, the sill or lower part of a win- 
 dow; a platform or flooring of plank 
 raised at the entrance of a dock : in 
 naval architecture, a piece of curved 
 timber fixed behind the lower part 
 of the stern of a ship. 
 
 Apsis, the east end of a church or 
 chancel ; sometimes applied to a 
 canopy over an altar; also to a 
 circle about a star or planet. 
 
 Apsis gradata, a bishop's throne in 
 cathedral churches. 
 
 Aquafortis, in chemistry, nitric acid 
 diluted : the more concentrated is 
 named spirit of nitre. 
 
 Aquamale, a holy-water basin. 
 
 Aqua regia, nitro-muriatic acid; a 
 compound of two parts nitric acid 
 and one part muriatic acid. 
 
 Aquatinta, in the arts, engraving 
 which resembles drawings in In- 
 dian ink. 
 
 Aqueduct, a conduit for water: a con- 
 struction of stone or timber, built 
 on uneven ground, to preserve the 
 level of water, and convey it by a 
 canal from one place to another. 
 
 Aquemola, a water-mill. 
 
 Aquila, a reading-desk, so called from 
 its shape being that of an eagle 
 with extended wings, supported by 
 a pedestal. 
 
 '''Arabesque, generally applied to a style 
 of ornament for pilasters, friezes, 
 etc., as those painted by Raffaelle 
 in the Vatican. 
 
 *" Arabo-tedesco, a term applied to the 
 Moorish style of buildings in Spain, 
 etc. 
 
 Ara diynitatis, an altar at which none 
 but the highest ecclesiastics per- 
 form divine rites. 
 
 Araeostyle, in architecture, the great- 
 est interval or distance which can 
 be made between columns, that is, 
 eight modules or four diameters ; 
 also a species of temple which has 
 its columns placed widely asunder. 
 
 Arbor, a spindle or axis upon which a 
 ring or wheel is turned in a lathe. 
 
 Arbor Dianas, in chemistry, crystals 
 formed by the combination of sil- 
 ver and mercury. 
 
 Arbores, brass branches for lights sus- 
 pended from ceilings. 
 
 Arboretum, a grove of trees in a park, 
 pleasure-ground, or garden. 
 
 Arbor vitce, a tree which attains to a 
 height of from 40 to 50 feet ; its 
 wood is of a reddish colour, very 
 light, soft, and fine-grained, and is 
 much used in house carpentry. 
 Arc, in geometry, part of the circum- 
 ference of a circle, or any curve 
 lying between two points ; a bow, 
 vault, or arch. 
 
 Area, a place in a vaulted chamber 
 for sepulchral purposes ; an exca- 
 vation before the basement story 
 of a house ; an enclosed space ; a 
 chest in which the Romans depo- 
 sited their money: the word is also 
 used to signify a beam of wood 
 which has a groove or channel hol- 
 lowed in it from one end to the 
 other. 
 
 ^Arcade, a series of recesses with 
 arched ceilings or soffits ; a covered 
 passage : in modern appliances, a 
 vaulted avenue, now much in vogue, 
 more particularly in Paris. Ar- 
 cades, though less magnificent than 
 colonnades, are of extraordinary 
 beauty when well contrived, afford- 
 ing shade from the sun and shelter 
 from the rain. Though not so mag- 
 nificent as colonnades, they are 
 stronger, more solid, and less ex- 
 pensive. They are proper for tri- 
 umphal entrances, gates of cities, of 
 palaces, of gardens, and of parks ; 
 for public squares, markets, or large 
 courts in general, and for all aper- 
 tures that require an extraordinary 
 width. 
 
 THEIR ORNAMENTS. The piers 
 of arcades may be decorated with 
 columns, pilasters, niches, and aper- 
 tures of different forms. The arch 
 itself may be turned either with 
 rockworked or plain rustic arch- 
 stones or voussoirs, or with an 
 
 17 
 
ARC 
 
 ARCH. 
 
 ARC 
 
 archivolt properly moulded. The 
 keystone is generally carved in the 
 form of a console, or sculptured 
 with some head, or the like. The 
 archivolt springs from an impost or 
 plat-band, or sometimes from co- 
 lumns ; but this is not to be prac- 
 tised except in cases of the most 
 urgent nature, for its makes neither 
 substantial nor beautiful work. 
 
 In arches that are of large dimen- 
 sions, the keystone should never be 
 omitted ; its carving, however, may 
 be dispensed with, if expense be an 
 object. When the piers are deco- 
 rated with disengaged columns, the 
 entablature must break round over 
 the columns; and the columns, 
 whether engaged or not, should 
 stand either on a pedestal or high 
 plinth, by which means they will 
 not only be kept dry, but their 
 bases will likewise be protected 
 from accidental damage. Arches 
 must always rise from an impost or 
 a plat-band; and if there be no 
 keystone to the archivolt, its sum- 
 mit should be kept down from the 
 under side of the architrave of the 
 accompanying order, at least half 
 the distance that it would be, were 
 a keystone employed, in order that 
 the disagreeable appearance of the 
 acute angle which it would other- 
 wise form with the architrave may 
 be avoided. 
 
 THEIR PROPORTIONS. The 
 height of arches to the under side 
 of their crowns should not exceed 
 twice their clear width, nor should 
 it be much less; the piers not less 
 than one-third the breadth of the 
 arch, nor more than two-thirds ; 
 but the piers at the angles should 
 be wider than the other piers by 
 one-half, or one-fourth at least. 
 
 Area, in Roman architecture, the 
 gutters of the cavedium. 
 
 Arc-boutant, a kind of arched but- 
 tress formed of a flat arch, or part 
 of an arch, and abutting against the 
 feet or sides of another arch or 
 vault, to support them, and prevent 
 them from bursting or giving way. 
 
 Arcella, in mediaeval architecture, a 
 cheese-room. 
 
 *Arch, the curved part of a building, 
 supported at its extremities only, 
 and concave towards the earth ; a 
 vaulted roof, or dome, constructed 
 either with bricks, stone, or other 
 materials : the arch of a bridge is 
 formed of segments of a circle, 
 elliptical or catenarian ; in Christian 
 architecture, arches display twenty- 
 two varieties of form. Arches 
 are used in large intercolumni- 
 ations of spacious buildings; in 
 porticoes, both within and without 
 temples ; in public halls, as ceil- 
 ings, the courts of palaces, cloisters, 
 theatres, and amphitheatres : they 
 are also used to cover the cellars in 
 the foundations of houses and pow- 
 der-magazines ; also as buttresses 
 and counterforts, to support large 
 walls laid deep in the earth ; 
 for triumphal arches, gates, win- 
 dows, etc. ; and, above all, for the 
 foundations of bridges and aque- 
 ducts: they are supported by piers, 
 abutments, imposts, etc. Arches 
 are of several kinds, circular, ellip- 
 tical, cycloidal, catenarian, etc., ac- 
 cording as their curve is in the form 
 of a circle, ellipse, cycloid, cate- 
 nary, etc. Arches are to be found 
 in the Greek theatres, stadia, and 
 gymnasia, some of them erected 
 probably 400 years before Christ. 
 The most ancient arches of which 
 we have correct data are those of 
 the cloacae at Rome. The Emperor 
 Hadrian threw a bridge over the 
 Cephisus, between the territories of 
 Attica and Eleusis, on the most 
 frequented road of Greece. 
 
 1 Arch (theory of the). This important 
 subject has exercised the talents 
 and ingenuity of some of the great- 
 est mathematicians in modern 
 times, and many different solutions 
 have been given to the various pro- 
 blems connected with it ; but, as 
 the greater part of them are founded 
 on suppositions that have no exist- 
 ence whatever either in nature or 
 practice, they have had a tendency 
 
 18 
 
ARC 
 
 ARCH. 
 
 ARC 
 
 rather to mislead than direct those 
 who are engaged in the operations 
 of bridge-building. Dr. Olinthus 
 Gregory, in the preface to his ex- 
 cellent work on 'Mechanics,' states, 
 that "theoretical and practical men 
 will most effectually promote their 
 mutual interests, not by aifecting 
 to despise each other, but by blend- 
 ing their efforts ; and further, that 
 an essential service will be done to 
 mechanical science, by endeavour- 
 ing to make all the scattered rays 
 of light they have separately thrown 
 upon this region of human know- 
 ledge converge to one point. 
 Gauthey, speaking of the theory of 
 La Hire, observes that such analy- 
 tical researches are founded on hy- 
 potheses which every day's experi- 
 ence contradicts. The following are 
 the principal writers on the equili- 
 brium of the arch. In 1691, the ce- 
 lebrated mathematicians, Leibnitz, 
 Huygens, James and John Ber- 
 nouilli, solved the problem of the 
 catenary curve : it was soon per- 
 ceived that this was precisely the 
 curve that should be given to an 
 arch of which the materials were in- 
 finitely small and of equal weight, 
 in order that all its parts may be 
 in equilibrium. In the ' Philoso- 
 phical Transactions' for the year 
 1697, it is stated that David Gre- 
 gory first noticed this identity ; but 
 his mode of argument, though suf- 
 ficiently rigorous, appears not to be 
 so perspicuous as could be desired. 
 In one of the posthumous works of 
 James Bernouilli, two direct solu- 
 tions of this problem are given, 
 founded on the different modes of 
 viewing the action of the voussoirs : 
 the first is clear, simple, and precise, 
 and easily leads to the equation of 
 the curve, which he shows to be 
 the catenary inyerted ; the second 
 requires a little correction, which 
 Cramer, the editor of his works, 
 has pointed out. In 1695, La 
 Hire, in his ' Treatise on Mecha- 
 nics,' laid down, from the theory of 
 the wedge, the proportion accord- 
 
 19 
 
 ing to which the absolute weight 
 of the materials of masonry ought 
 to be increased from the keystone 
 to the springing in a semicircular 
 arch. The historian of the ' Acade- 
 my of Sciences' relates, in the vo- 
 lume for the year 1704, that Parent 
 determined on the same principle, 
 but only by points, the figure of the 
 extrados of an arch, the intrados 
 being a semicircle, and found the 
 force or thrust of a similar arch 
 against the piers. In the ' Memoirs 
 of the Academy of Sciences' for the 
 year 1712, La Hire gave an inves- 
 tigation of the thrusts in arches 
 under a point of view suggested by 
 his own experiments : he supposed 
 that arches, the piers of which had 
 not solidity enough to resist the 
 thrust, split towards the haunches 
 at an elevation of about 45 degrees 
 above the springings or impost ; he 
 consequently regarded the upper 
 part of the arch as a wedge that 
 tends to separate or overturn the 
 abutments, and determined, on the 
 theory of the wedge and the lever, 
 the dimensions which they ought 
 to have to resist this single effort. 
 Couplet, in a memoir composed of 
 two parts, the first of which was 
 printed in the volume of the Aca- 
 demy for 1 729, treats of the thrusts 
 of arches and the thickness of the 
 voussoirs, by considering the mate- 
 rials infinitely small, and capable of 
 sliding over each other without any 
 pressure or friction. But, as this 
 hypothesis is not exactly conform- 
 able to experiment, the second part 
 of the memoir, printed in the vo- 
 lume for 1730, resumes the ques- 
 tion by supposing that the mate- 
 rials have not the power of sliding 
 over each other, but that they can 
 raise themselves and separate by 
 minute rotatory motions. It can- 
 not however be said that Couplet 
 has added materially to the theo- 
 ries of La Hire and Parent, and 
 none of them treated the subject, 
 either in theory and practice, in 
 such a satisfactory manner as was 
 
ARC 
 
 ARCH. 
 
 ARC 
 
 afterwards done by Coulomb. ^Sub- 
 sequently a memoir was published 
 by Bouguer on the curve lines that 
 are most proper for the formation 
 of the arches of domes. He con- 
 siders that there may be an infinite 
 number of curve lines employed 
 for this purpose, and points out 
 the mode of selecting them. He 
 lays it down uniformly that the 
 voussoirs have their surfaces infi- 
 nitely smooth, and establishes, ou 
 this hypothesis, the conditions of 
 equilibrium in each horizontal 
 course of the dome, but has not 
 given any method of investigating 
 the thrusts of arches of this kind, 
 nor of the forces that act upon the 
 masonry when the generating curve 
 is subjected to given conditions. In 
 1770, Bossut gave investigations of 
 arches of the different kinds, in 
 two memoirs, which were printed 
 among those of the Academy of 
 Sciences for the years 1 774 and 
 1776 : he appears to have been 
 engaged in this in consequence 
 of some disputes concerning the 
 dome of the French Pantheon, 
 begun by the celebrated architect 
 Soufflot, and finished from his de- 
 signs. In 1772, Dr. Hutton pub- 
 lished his principles of bridges, in 
 which he investigated the form of 
 curves for the intrados of an arch, 
 the extrados being given, and vice 
 versa. He set out by developing 
 the properties of the equilibrated 
 polygon, which is extremely useful 
 in the equilibrium of structures. 
 Mr. Attwood has written a disserta- 
 tion on the construction of arches 
 on the same principles as La Hire. 
 
 'Arch, in architecture, a concave struc- 
 ture raised or turned upon a mould, 
 called the centering, in form of the 
 arc of a curve, and serving as the 
 inward support of some superstruc- 
 ture. Sir Henry Wotton says, "An 
 arch is nothing but a narrow or 
 contracted vault ; and a vault is a 
 dilated arch." 
 
 Arch, in geometry, a part of any 
 curved line, as of a circle or ellipsis. 
 
 ' Arch, in masonry, a part of a building 
 suspended over a hollow, and con- 
 cave towards the area of the hol- 
 low : the top of the wall or walls 
 which receives the first archstones 
 is technically called the abutment 
 or springing. 
 
 Arch, in mining, a piece of ground left 
 unworked. 
 
 Arch-band, applied by workmen to 
 that portion of an arch or rib 
 which is seen below the general 
 surface of vaulting. 
 
 Arch-brick, a wedge-shaped brick 
 employed in the construction of 
 arches. 
 
 Arch-buttress, a piece of insulated 
 masonry usually named a flying- 
 buttress, extending from the clere- 
 story of a church and over the roof 
 of its aisle, where it rests on the 
 buttress of the outer wall. 
 
 Arch of equilibration, that which is in 
 equilibrium in all its parts, having 
 no tendency to break in one part 
 more than in another. 
 
 Arch, triumphal, a building of which 
 an arch is the principal feature, 
 usually raised to commemorate 
 some great achievement. 
 
 Archaeology, the study of ancient art, 
 but more particularly that of the 
 middle ages. 
 
 Arched, in mining: the roads in a 
 mine, when built with stones or 
 bricks, are generally arched level 
 drifts. 
 
 Archeion, a recess in a Grecian tem- 
 ple, for the reception of the trea- 
 sures of the deity to whom the 
 temple was dedicated. 
 
 Archeion, in Athens, the office in 
 which the decrees of the people 
 and other state documents were 
 preserved. 
 
 Arches, Norman, semicircular, which 
 form continued to the latest date 
 of this style, and is frequently in- 
 termixed with pointed arches, even 
 when other parts had advanced 
 into the next style, of which the 
 Temple Church is an instance. 
 
 There are some Norman arches 
 more than a semicircle, the horse- 
 
 20 
 
ARC 
 
 ARCHITECTURE. 
 
 ARC 
 
 shoe,' and a few instances of a 
 double arch. 
 
 Archetus, a saw for cutting stones : 
 Muratori used the terra for a crane 
 or pulley for raising stones to the 
 upper part of a building. 
 
 Archimedes screw-propeller, in 1836, 
 was launched by T. P. Smith, pa- 
 tentee. The vessel 232 tons, 125 
 feet long, 21 feet 10 inches beam, 
 80-horse power. 
 
 Archimedean screw, a machine in- 
 vented by Archimedes for raising 
 water ; also now applied to propel 
 vessels through water. 
 
 Archiepiscopal palace, the dwelling 
 of an archbishop. 
 
 Architect, a person skilled in the art 
 of building ; one who forms plans 
 and designs for edifices, conducts 
 the work, and directs the secondary 
 artificers employed ; and whose 
 emoluments are generally 5 per 
 cent, on the amount of money ex- 
 pended. 
 
 Architecture, a science applicable to 
 the art of constructing domestic, 
 ecclesiastical, municipal, palatial, 
 or other buildings, and the adorn- 
 ment of the same according to the 
 rules of the several orders, Doric, 
 Ionic, and Corinthian, also the Tus- 
 can and Composite, from Roman 
 models, or other styles, each for its 
 purpose, such as is usually called 
 Gothic architecture, and modes 
 subservient to climate and fashion, 
 or caprice. " Architecture," says 
 Palladio, " being grounded upon 
 rules taken from the imitation of 
 Nature, admits of nothing that is 
 contrary or foreign to that order 
 which Nature has prescribed to all 
 things. An architect is not re- 
 strained from departing sometimes 
 from common methods or usage, 
 provided such variation be agree- 
 able and natural." 
 
 The public at large has a claim 
 over the architecture of a country. 
 It is common property, inasmuch 
 as it involves the national taste and 
 character ; and no man has a right 
 to pass off his own barbarous in- 
 
 ventions as the national taste, and 
 to hand down to posterity his own 
 ignorance and disgrace to become 
 a satire and a libel on the know- 
 ledge and taste of his age. 
 Architecture, the Orders of. Among 
 the ancients, the use of the orders 
 was very frequent ; many parts of 
 their cities were provided with spa- 
 cious porticoes, their temples were 
 surrounded with colonnades, and 
 their theatres, baths, basilicae, tri- 
 umphal arches, mausolea, bridges, 
 and other public buildings were 
 profusely enriched with columns ; 
 as were likewise the courts, vesti- 
 bules, and halls of their private 
 villas and houses. 
 
 In pure architecture, says A. W. 
 Pugin, the smallest detail should 
 have a meaning or serve a purpose ; 
 and even the construction itself 
 should vary with the material em- 
 ployed, and the designs should be 
 adapted to the material in which 
 they are executed. 
 
 Strange as it may appear at first 
 sight, it is in pointed architecture 
 alone that these great principles 
 have been carried out : we may be 
 enabled to illustrate them from the 
 vast cathedral to the simplest erec- 
 tion. Moreover, the architects of 
 the middle ages were the first who 
 turned the natural properties of 
 the various materials to their full 
 account, and made their mechanism 
 a vehicle for their art. The won- 
 derful strength and solidity of their 
 buildings are the result, not of 
 quantity or size of the stones em- 
 ployed, but of the art of their dis- 
 position. 
 
 The two following pages contain 
 a synopsis of the proportions of 
 the Orders, and of various exam- 
 ples of each, compiled by Mr. 
 W. H. Leeds for Pugin's edition 
 of Normand's ' Parallel of the Or- 
 ders.' 
 
 21 
 
ARC ARCHITECTURE. 
 
 Names of the Orders. 
 
 Base. 
 
 Column. 
 
 Capital. 
 
 Archi- 
 trave. 
 
 Frieze. 
 
 TUSCAN. 
 Palladio . . 
 
 3 -a 
 
 3 1 tL 
 
 1 
 1 
 1 
 1 
 
 i i * 
 
 3 a o. 
 
 700 
 7 1 
 600 
 700 
 
 5 1 
 5 1 
 4 15 
 5 25 
 6 20 
 8 10 
 5 1 
 600 
 7 1 18 
 7 1 
 800 
 800 
 8 1 
 800 
 800 
 
 41 1 1 
 1 
 1 
 1 
 1 
 
 28 
 1 
 1 23 
 284 
 )6 
 25$ 
 23 
 23 
 1 2| 
 1 
 1 
 1 
 1 
 1 
 1 
 
 B -a 
 
 1 I i. 
 
 1 5 
 
 o i 24 
 
 1 
 25 
 
 1 144 
 20 
 
 ;; 4 
 
 9 
 16 
 
 i-g . 
 
 3 S 
 
 26 
 9 
 
 5 
 
 o 194 
 
 25 ( 
 
 o 24 
 
 7 
 14 
 
 
 Serlio 
 
 Vignola 
 
 DORIC. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 2 
 
 5 
 
 
 
 16 
 15 
 15 
 15 
 15 
 15 
 15 
 15 
 
 o 19 
 
 18J 
 
 Doric Order at Albano .... 
 
 . . . 
 
 Palladio 
 
 1 
 1 
 1 
 1 
 1 
 
 1 
 25 
 
 o o 234 
 
 1 0| 
 1 
 1 
 22 
 22 
 20 
 
 o o 204 
 o o 224 
 
 1 84 
 21 
 25 
 23 
 20 
 
 o o 224 
 
 24 
 234 
 
 
 
 Viola 
 
 IONIC. 
 
 Temple on the Ilissus .... 
 Temple of Minerva Polias, Athens 
 Temple of Erechtheus, Athens . 
 Temple of Fortuna Virilis . . 
 Theatre of Marcellus .... 
 Baths of Diocletian . . 
 
 800 
 9 1 
 900 
 8 1 24 
 900 
 8 1 
 9 
 8 1 15 
 900 
 7 1 
 800 
 
 10 
 9 1 15 
 9 15 
 9 1 
 10 6| 
 10 15 
 9 1 164 
 9 1 44 
 
 1 94 
 
 o i 134 
 
 1 10 
 29 
 
 o i 14 
 
 o i 14 
 
 1 U 
 
 o o 264 
 o i 04 
 
 1 
 
 o i 14 
 
 24 
 
 o 27 
 
 11 
 15 
 6| 
 10 
 
 o 71 
 
 o 124 
 
 18 
 83 
 16 
 63 
 94 
 94 
 
 
 
 
 
 
 
 144 
 
 o 54 
 
 11 
 
 
 
 
 o o 27 
 
 25 
 
 214 
 
 84 
 13 
 4 
 6 
 15 
 
 o 74 
 
 
 
 
 21 
 11| 
 
 o 164 
 o 124 
 o 134 
 
 12fc 
 
 o 1-23 
 
 12 
 14 
 13fc 
 14* 
 15 
 
 91 
 134 
 
 
 8 
 12 
 15 
 
 
 
 16 
 15 
 
 144 
 10 
 9 
 15 
 
 1 254 
 
 285 
 $ 
 28 
 27 
 28 
 15 
 
 o 224 
 
 
 
 QJ 
 27i 
 
 12; 
 
 10 
 133 
 13 
 9i 
 12 
 15 
 105 
 14; 
 10 
 
 10 
 9: 
 23, 
 2 
 15 
 7 
 
 
 14 
 25 
 14 
 
 1; 
 15 
 
 Palladio 
 
 
 Vignola 
 
 
 Alberti 
 
 CORINTHIAN. 
 Lantern of Demosthenes, Athens 
 Temple of Jupiter Olympius, do. 
 Incantada at Salonica .... 
 Arch of Theseus, Athens . . . 
 Temple of Jupiter Stator, Rome 
 Temple of Jupiter Tonans 
 Portico of the Pantheon . . . 
 Interior of the Pantheon . . . 
 
 Temple of Antoninus and Faustina 
 
 24 
 
 o o 204 
 
 24 
 
 9 1 6 
 10 
 9 1 7 
 
 Arch of Constantine .... 
 Temple of Mars the Avenger. . 
 Basilica of Antoninus .... 
 Temple of the Sibyl, Tivoli . . 
 Palladio . ...... 
 
 23 
 164 
 1 
 1 
 1 
 1 
 1 
 
 23 
 20 
 22 
 
 o i 14 
 
 1 
 1 
 
 10 113 
 9 25 
 9 1 
 10 
 10 
 900 
 900 
 
 10 6 
 9 1 10 
 
 10 o 293 
 
 10 
 9 1 15 
 10 
 
 500 
 
 
 Vignola 
 Serlio 
 
 Alberti . . ... 
 
 COMPOSITE. 
 Arch of Titus 
 
 Arch of Septimius Severus . . 
 
 Palladio 
 
 
 
 Caryatides of the Temple of 1 
 Pandrosus / 
 
 22 
 
ARCHITECTURE. 
 
 ARC 
 
 lice. 
 
 Entabla- 
 ture. 
 
 Interco- 
 umniation 
 
 Diameter of 
 column. 
 
 Architecture, qualities of. There 
 is perhaps no subject on which 
 
 
 
 . 
 
 
 persons are more apt to differ in 
 
 0. 
 
 Hi 
 
 Hi 
 
 feet, inches. 
 
 their opinions than on the beauty 
 of a building. In architecture the 
 
 j j 
 
 i 1 224 
 
 
 
 creative power of Nature herself is 
 
 
 
 1 1 
 
 
 
 the model imitated. It is an art 
 
 10 
 
 1 110 
 
 
 
 wliicli ciDDCfils dircctlv to the un- 
 
 
 
 
 
 
 
 
 
 
 derstanding, and has not the means 
 
 26 
 
 200 
 
 2 20 
 21 ft 
 
 6 1 j^ 
 
 of flattering the senses in the same 
 
 28* 
 
 2 Oil 
 
 1 1 12 
 
 1 
 2 10 
 
 6 l/Q- 
 7 0'03 
 
 way as the sister arts: hence its 
 
 74 
 
 2 44 
 
 2 25 
 
 
 productions are not universally ap- 
 
 25 
 
 1 1 18 
 
 3 1 5 
 
 2' s'- 10 
 
 preciated. The beautiful models 
 
 
 
 2 15 
 
 . 
 
 of Nature, however, are the index 
 
 " 
 
 
 
 4 4*05 
 
 and guide of the painter and sculp- 
 
 63 
 
 1 1 23J 
 
 
 
 tor * a successful imitation of these 
 
 5 
 
 1 1 20 
 
 
 
 
 16 
 
 203 
 
 
 
 models, even without an advance 
 
 8 
 
 1 23 
 
 2 1 15 
 
 . . . 
 
 on the part of the artist towards 
 
 17 
 
 207 
 
 4 11 
 
 
 those higher intellectual beauties 
 
 15 
 10 
 
 200 
 1 1 25 
 
 . . . 
 
 . . . 
 
 which distinguish the historical 
 
 10 
 
 1 1 25 
 
 
 
 painter, is capable of affecting us 
 
 
 
 
 
 with very agreeable sensations. 
 
 2 
 
 2 16 
 
 2 15 
 
 1 9'4 
 
 The object of an artist's inquiry is 
 
 74 
 
 2 174 
 
 300 
 
 2 9'4 
 2 3'8 
 
 not so much to investigate meta- 
 
 104 
 
 2 174 
 
 1 1 20 
 215 
 
 3 2 
 
 physically the cause of beauty in 
 
 6 
 
 16 
 
 2 25f 
 1 18 
 
 
 
 the productions of his art, as to 
 
 16 
 
 12 
 
 1 19 
 1 25 
 
 2 74 
 
 . . . 
 
 study the effects that flow from 
 those which by the common con- 
 
 
 15 
 
 
 
 
 sent of ages are esteemed beautiful, 
 
 2 
 10 
 
 o 244 
 
 1 10 
 
 . . . 
 
 . . . 
 
 and thus shorten his road by an a 
 
 
 
 
 
 priori method. It is in this way 
 
 20 
 
 2 204 
 
 206 
 
 1 2 
 
 that he will more readily obtain 
 
 18 
 
 1 1 27 
 
 300 
 
 2 11-3 
 
 infonnation on those qualities 
 
 13* 
 
 2 7 
 
 3 24 
 
 2 5' 9" 
 
 which act on the understanding 
 
 164 
 
 95 
 
 2 014 
 2 1 6* 
 
 2 11| 
 
 1 1 5 
 1 1 34 
 
 4 10& 
 4 8i% 
 
 and excite our affections by means 
 of the beautiful result they exhibit. 
 
 24 " 
 
 2 l6| 
 
 2 15 
 
 4 11 
 
 These qualities may be classed as 
 
 21* 
 
 2 15^ 
 
 2 24 
 
 3 8 T V 
 
 follows : 
 
 254 
 
 2 284 
 
 . . . 
 
 3 6 
 
 MAGNITUDE AND SOLIDITY, as 
 
 224 
 
 2 164 
 2 26| 
 
 1 1 14 
 1 1 
 
 4 1 ^ 
 
 qualities which affect the eye. 
 
 284 
 
 2 234 
 
 
 2 UTO 
 
 ORDER AND HARMONY, as quali- 
 
 
 . . . 
 
 1 284 
 
 5 ITO 
 
 ties which affect the understanding. 
 
 3 
 
 1 112^ 
 
 1 1 10^ 
 2 14 
 
 A l 
 
 RICHNESS AND SIMPLICITY, as 
 
 174 
 
 1 1 24 
 
 2 
 
 2 4? 
 
 qualities which excite the affec- 
 
 19 
 
 203 
 
 200 
 
 
 tions,-^-in which taste is the prin- 
 
 
 
 210 
 1 1 16 
 
 2 20 
 
 
 cipal guide. These qualities an- 
 
 10 
 
 1 1 10 
 
 
 
 swer to the three divisions which 
 
 
 
 
 
 those who have written on archi- 
 
 2 
 
 2 1 2 
 
 . . . 
 
 2 10 : % 
 
 tecture have usually adopted, 
 
 84 
 21 
 
 2 19 
 2 194 
 
 , . 
 
 2 Ofk 
 
 namely 
 
 20 
 
 200 
 
 
 
 CONSTRUCTION, in which the 
 
 16J 
 
 1 1 27 
 
 
 
 chief requisites are solidity and 
 
 
 
 2 1 
 
 
 
 strength. 
 
 ) 
 
 1 1 254 
 
 . . . 
 
 . . . 
 
 DESIGN OR DISPOSITION, in 
 
ARC 
 
 ARCHITECTURE. 
 
 ARC 
 
 which the principal requisites are 
 order and harmony. 
 
 DECORATION, whose requisites 
 are richness or simplicity, accord- 
 ing to the nature of the composi- 
 tion. 
 
 That there are, however, many 
 other circumstances which tend to 
 the production of an agreeable and 
 beautiful result, is sufficiently ob- 
 vious : one of them should be more 
 particularly noticed, because there 
 can be no doubt of its influence in 
 the excitement of our admiration 
 of the splendid monuments of Gre- 
 cian art ; it is an association with 
 the times and countries which are 
 most hallowed in our imagination. 
 It is difficult for us to see them, 
 even in their modern copies, with- 
 out feeling them operate upon our 
 minds, as relics of those polished 
 nations where they first arose, and 
 of that great people by whom they 
 were afterwards borrowed. 
 
 The business of an architect re- 
 quires him rather to be a learned 
 judge than a skilful operator ; and 
 when he knows how to direct and 
 instruct others with precision, to 
 examine, judge, and value their 
 performances with masterly accu- 
 racy, he may truly be said to have 
 acquired all that most men can ac- 
 quire : there are but few instances 
 of such prodigies as Michael An- 
 gelo Buonarroti, who was at once 
 the first architect, painter, geome- 
 trician, anatomist, and sculptor of 
 his time. 
 
 Vitruvius furthermore observes, 
 that an art enriched with such 
 variety of knowledge is only to be 
 learned by long and constant appli- 
 cation ; and advises his contempo- 
 raries never to assume the title of 
 architects till they are perfect mas- 
 ters of their own profession, and of 
 the arts and sciences with which it 
 is connected ; a caution that even 
 in the present times may perhaps 
 not be unnecessary. 
 Architecture, Naval, the art of con- 
 structing ships and vessels to float 
 
 on the waters. Naval architecture 
 has suffered more than most other 
 sciences by the arbitrary systems 
 of those interested in its improve- 
 ment. Disregarding the fundamen- 
 tal principles of all floating bodies, 
 and too hastily giving up as hope- 
 less the attainment of a theory 
 combining experiment with esta- 
 blished scientific principles, they 
 have contented themselves with 
 ingeniously inventing mechanical 
 methods of forming the designs of 
 ships' bodies, which they did not 
 even pretend to prove had any 
 connection with the properties of 
 the machine necessary to insure 
 the qualities conducive to its in- 
 tended use. For instance, some 
 invented methods of forming ships' 
 bodies of arcs of circles ; others, of 
 arcs of ellipses, parabolas, or of 
 whatever curve they might arbi 
 trarily assume. They did not at- 
 tempt to show that these curves 
 possessed any property which would 
 render a ship a faster sailer, a more 
 weatherly or safer ship, than any 
 other curves which might have 
 been adopted in the construction 
 of the ship's body. 
 
 Architholw, a round chamber, the 
 sudatorium of a Roman bath. 
 
 Architrave, the lower of the three 
 principal members of the entabla- 
 ture of an order, being the chief 
 beam resting immediately on the 
 column. 
 
 Architrave cornice, an entablature 
 consisting of an architrave and cor- 
 nice only, without the interposition 
 of a frieze. 
 
 Architrave doors, those which have 
 an architrave on the jambs and 
 over the door. 
 
 Architrave windows, of timber, arc 
 usually an ogee raised out of th( 
 solid timber, with a roll over it. 
 
 Archivolt, a collection of member: 
 in the face of an arch, coucentrii 
 with the intrados, and supporte( 
 by imposts. 
 
 Archivolt of the arch of a bridge, 
 the curve line formed by the uppe 
 
 24 
 
\RC 
 
 AKK. 
 
 ARK 
 
 sides of the arch-stones in the face 
 of the work ; it is sometimes un- 
 derstood to be the whole set of 
 arch-stones which appear in the 
 face of the work. 
 
 Archivoltum, a cesspool or common 
 sewer. 
 
 Archway, an aperture in a building 
 covered with a vault. 
 
 Arcs doubleaux, a French term for 
 arch-hand, and employed by Eng- 
 lish writers from the time of De 
 i'Orme, etc. 
 
 Arcunio (M.), born in Rome, was 
 both an architect and painter, 
 died about 1640. 
 
 Arcnla, a small coffer or box. 
 
 Arcus, an area in the form of an 
 ancient basilica. 
 
 At-cus, an arch : a true arch is formed 
 of a series of wedge-like stones or 
 of bricks supporting each other, 
 and all bound together by their 
 mutual pressure. 
 
 Arcus-toralis, in medieval architec- 
 ture, the lattice separating the 
 choir from the nave in a basilica. 
 
 Arcutio, a machine consisting of 
 hoops. 
 
 Ardeme (John) was clerk of the 
 work at the building of the monu- 
 ment in Westminster Abbey Church 
 to King Henry V., who died in 
 1422. 
 
 Ardesia, a slate used in Italy for 
 covering roofs. 
 
 Area, in geometry, the superficial 
 content of any figure. 
 
 Areas, in computing the superficial 
 content of land, are generally ex- 
 pressed in statute acres, roods, and 
 perches. The acre is equal to 10 
 square chains of 66 feet, or 22 
 yards in length. 
 
 Area drain, a narrow area drain not 
 covered, on the basement floor of 
 a building, to remedy or prevent 
 dampness in the connecting walls. 
 
 Area wall, the wall which forms the 
 sides of an area. 
 
 Arena, the area or floor of an amphi- 
 theatre. 
 
 Arenarium, an amphitheatre, ceme- 
 tery, crypt, or sepulchre. 
 
 Areometer, an instrument for measu- 
 ring the density or gravity of fluids. 
 
 Areopagus, the court in which the 
 Areopagites, or supreme judges of 
 Athens, assembled. 
 
 Areostylos, intercolumniations, when 
 their distance from each other is 
 four diameters. 
 
 Arerde, reared, built, or raised up. 
 
 Argand lamp, a lamp with a circular 
 wick, through which a current of 
 air passes. 
 
 Arayrocopeion, the mint at Athens. 
 
 Aristotele (G.F.), architect and sculp- 
 tor, commenced, from the designs 
 of Raffaelle, the Palazzo Pandol- 
 fini at Florence; he died in 1530. 
 
 Ark, a shelter, a place of protection 
 from floods : in the time of Moses, 
 a coffer or sort of bark, in shape 
 and appearance like a chest or 
 trunk ; also described by Moses as 
 a little wicker basket, in which he 
 was exposed on the Nile. The 
 ancients inform us that the Egyp- 
 tians used on the Nile barks made 
 of bulrushes. 
 
 Ark, a chest used in farm-houses for 
 keeping meal or flour. 
 
 Ark (Noah's) : " And this is the fash- 
 ion which thou shalt make it of: the 
 length of the ark shall be three 
 hundred cubits, the breadth of it 
 fifty cubits, and the height of it 
 thirty cubits." It is supposed by 
 some authors to have been a mere 
 variationfromtheordinaryconstruc- 
 tion of houses for residence, chang- 
 ingits character from that of a house 
 for standing to that of a house for 
 floating. Niebuhr compares it with 
 ordinary houses of the East, the 
 sides of which are constructed of 
 upright supports of timber, plas- 
 tered over with clay. The appli- 
 cation of canes, split and laid across 
 these quarterings, is very like the 
 usage of laths, which are common 
 everywhere. The same may be 
 said of a coating of bitumen, a 
 substance employed on account of 
 its property of resisting water; and 
 the mode of its application might 
 be similar to our plastering. It is 
 
 25 
 
ARC 
 
 ARCHITECTURE. 
 
 ARC 
 
 which the principal requisites are 
 order and harmony. 
 
 DECORATION, whose requisites 
 are richness or simplicity, accord- 
 ing to the nature of the composi- 
 tion. 
 
 That there are, however, many 
 other circumstances which tend to 
 the production of an agreeable and 
 beautiful result, is sufficiently ob- 
 vious : one of them should be more 
 particularly noticed, because there 
 can be no doubt of its influence in 
 the excitement of our admiration 
 of the splendid monuments of Gre- 
 cian art ; it is an association with 
 the times and countries which are 
 most hallowed in our imagination. 
 It is difficult for us to see them, 
 even in their modern copies, with- 
 out feeling them operate upon our 
 minds, as relics of those polished 
 nations where they first arose, and 
 of that great people by whom they 
 were afterwards borrowed. 
 
 The business of an architect re- 
 quires him rather to be a learned 
 judge than a skilful operator ; and 
 when he knows how to direct and 
 instruct others with precision, to 
 examine, judge, and value their 
 performances with masterly accu- 
 racy, he may truly be said to have 
 acquired all that most men can ac- 
 quire : there are but few instances 
 of such prodigies as Michael An- 
 gelo Buonarroti, who was at once 
 the first architect, painter, geome- 
 trician, anatomist, and sculptor of 
 his time. 
 
 Vitruvius furthermore observes, 
 that an art enriched with such 
 variety of knowledge is only to be 
 learned by long and constant appli- 
 cation ; and advises his contempo- 
 raries never to assume the title of 
 architects till they are perfect mas- 
 ters of their own profession, and of 
 the arts and sciences with which it 
 is connected ; a caution that even 
 in the present times may perhaps 
 not be unnecessary. 
 Architecture, Naval, the art of con- 
 structing ships and vessels to float 
 
 on the waters. Naval architecture 
 has suffered more than most other 
 sciences by the arbitrary systems 
 of those interested in its improve- 
 ment. Disregarding the fundamen- 
 tal principles of all floating bodies, 
 and too hastily giving up as hope- 
 less the attainment of a theory 
 combining experiment with esta- 
 blished scientific principles, they 
 have contented themselves with 
 ingeniously inventing mechanical 
 methods of forming the designs of 
 ships' bodies, which they did not 
 even pretend to prove had any 
 connection with the properties of 
 the machine necessary to insure 
 the qualities conducive to its in- 
 tended use. For instance, some 
 invented methods of forming ships' 
 bodies of arcs of circles ; others, of 
 arcs of ellipses, parabolas, or of 
 whatever curve they might arbi- 
 trarily assume. They did not at- 
 tempt to show that these curves 
 possessed any property which would 
 render a ship a faster sailer, a more 
 weatherly or safer ship, than any 
 other curves which might have 
 been adopted in the construction 
 of the ship's body. 
 
 Architholus, a round chamber, the 
 sudatorium of a Roman bath. 
 
 Architrave, the lower of the three 
 principal members of the entabla- 
 ture of an order, being the chief 
 beam resting immediately on the 
 column. 
 
 Architrave cornice, an entablature 
 consisting of an architrave and cor- 
 nice only, without the interposition 
 of a frieze. 
 
 Architrave doors, those which have 
 an architrave on the jambs and 
 over the door. 
 
 Architrave windows, of timber, are 
 usually an ogee raised out of the 
 solid timber, with a roll over it. 
 
 Archivolt, a collection of members 
 in the face of an arch, concentric 
 with the intrados, and supported 
 by imposts. 
 
 Archivolt of the arch of a bridge, 
 the curve line formed by the uppei 
 
 24 
 
ARK. 
 
 ARK 
 
 sides of the arch-stones in the face 
 of the work ; it is sometimes un- 
 derstood to be the whole set of 
 arch-stones which appear in the 
 face of the work. 
 ! Archivoltum, a cesspool or common 
 
 sewer. 
 
 ! Archway, an aperture in a building 
 covered with a vault. 
 
 Arcs doublcaux, a French term for 
 arch-band, and employed by Eng- 
 lish writers from the time of De 
 I'Orme, etc. 
 
 Arconio (M.), born in Rome, was 
 both an architect and painter, 
 died about 1640. 
 
 Arcula, a small coffer or box. 
 
 Arcus, an area in the form of an 
 ancient basilica. 
 
 Arcus, an arch : a true arch is formed 
 of a series of wedge-like stones or 
 of bricks supporting each other, 
 and all bound together by their 
 mutual pressure. 
 
 Arcus-toralis, in medieval architec- 
 ture, the lattice separating the 
 choir from the nave in a basilica. 
 
 Arcutio, a machine consisting of 
 
 hoops. 
 
 j Ardeme (John) was clerk of the 
 work at the building of the monu- 
 ment in Westminster Abbey Church 
 to King Henry V., who died in 
 1422. 
 
 Ardesia, a slate used in Italy for 
 covering roofs. 
 
 Area, in geometry, the superficial 
 content of any figure. 
 
 Areas, in computing the superficial 
 content of land, are generally ex- 
 pressed in statute acres, roods, and 
 perches. The acre is equal to 10 
 square chains of 66 feet, or 22 
 yards in length. 
 
 Area drain, a narrow area drain not 
 covered, on the basement floor of 
 a building, to remedy or prevent 
 dampness in the connecting walls. 
 
 Area wall, the wall which forms the 
 sides of an area. 
 
 Arena, the area or floor of an amphi- 
 theatre. 
 
 Arenarium, an amphitheatre, ceme- 
 tery, crypt, or sepulchre. 
 
 Areometer, an instrument for measu- 
 ring the density or gravity of fluids. 
 
 Areopagus, the court in which the 
 Areopagites, or supreme judges of 
 Athens, assembled. 
 
 Areostylos, intercolumniations, when 
 their distance from each other is 
 four diameters. 
 
 Arerde, reared, built, or raised up. 
 
 Argand lamp, a lamp with a circular 
 wick, through which a current of 
 air passes. * 
 
 Argyrocopeion, the mint at Athens. 
 
 Aristotele (G.F.), architect and sculp- 
 tor, commenced, from the designs 
 of Raffaelle, the Palazzo Pandol- 
 fini at Florence; he died in 1530. 
 
 Ark, a shelter, a place of protection 
 from floods : in the time of Moses, 
 a coffer or sort of bark, in shape 
 and appearance like a chest or 
 trunk ; also described by Moses as 
 a little wicker basket, in which he 
 was exposed on the Nile. The 
 ancients inform us that the Egyp- 
 tians used on the Nile barks made 
 of bulrushes. 
 
 Ark, a chest used in farm-houses for 
 keeping meal or flour. 
 
 Ark (Noah's} : " And this is the fash- 
 ion which thou shalt make it of : the 
 length of the ark shall be three 
 hundred cubits, the breadth of it 
 fifty cubits, and the height of it 
 thirty cubits." It is supposed by 
 some authors to have been a mere 
 variation from the ordinary construc- 
 tion of houses for residence, chang- 
 ingits character from that of a house 
 for standing to that of a house for 
 floating. Niebuhr compares it with 
 ordinary houses of the East, the 
 sides of which are constructed of 
 upright supports of timber, plas- 
 tered over with clay. The appli- 
 cation of canes, split and laid across 
 these quarterings, is very like the 
 usage of laths, which are common 
 everywhere. The same may be 
 said of a coating of bitumen, a 
 substance employed on account of 
 its property of resisting water; and 
 the mode of its application might 
 be similar to our plastering. It is 
 
ARM 
 
 ASPHALTUM. 
 
 ART 
 
 probable however that Noak's a^k 
 resembled the Egyptian boats in 
 form; and if we reckon the Hebrew- 
 cubit at 21 inches, the ark of Noah 
 was 512 feet long, 87 wide, and 
 52 high ; and the internal capacity 
 of it was 357,600 cubical cubits. 
 If we suppose the cubit to be only 
 18 inches, its length was 450 feet, 
 its width 75, and its height 45. 
 Its figure was an oblong square, 
 and the covering had a declivity to 
 carry off water. Its length ex- 
 ceeded that of most churches in 
 Europe. The wood used for the 
 ark was called gopher-wood, square 
 pieces of cedar or box, or woods 
 that do not quickly perish : by some 
 it has been supposed to have been 
 constructed of cypress-wood. 
 
 Armarium, a niche or cupboard near 
 
 the side of an altar. 
 i Armenian architecture, the edifices 
 in Armenia, erected previously to 
 the cultivation of a Graeco-Roman 
 architecture, supposed A. D. 260- 
 314. 
 
 Armilla, an ornament worn by Greek 
 men and women as a bracelet or an 
 armlet. 
 
 ! Armour, a defensive clothing of me- 
 tal. 
 
 Armoury, a storehouse or room in 
 which armour is preserved. 
 
 Arnotto (colour), the name of a ve- 
 getable substance from the West 
 Indies, of an orange-red colour, 
 soluble in water and spirit of wine, 
 but very fugitive and changeable, 
 and not adapted for painting. It is 
 principally used by the dyer, and 
 in colouring cheese. It is also an 
 ingredient in lacquering. 
 
 Aronade, embattled, a junction of 
 several lines forming indentations. 
 
 Arragonite, a remarkable form of 
 carbonate of lime, found in differ- 
 ent shapes, from hexagonal prisma- 
 tic crystals of coralloid masses. 
 
 Arris, in joinery and masonry, the 
 line of concourse, edge, or meeting 
 of two surfaces. 
 
 Arris fillet, a slight piece of timber 
 of a triangular section, used in 
 
 raising the slates against chimney- 
 shafts, etc. 
 
 Arris gutter, a wooden gutter of the 
 V form, fixed to the eaves of a 
 building. 
 
 Arris-wise, in bricklaying, tiles laid 
 diagonally. 
 
 Arshin, a Russian measure of length, 
 equal to 2 feet English. 
 
 Arsenal, a building for naval or mili- 
 tary stores. 
 
 Arsenic, a metal of a crystalline 
 appearance, and very brittle. It 
 sublimes out of the air unchanged 
 at 360, but in air it is oxidated, 
 and becomes arsenious acid : it is 
 occasionally found alone, but is ge- 
 nerally combined with nickel, co- 
 balt, and other metals. 
 
 Artesian wells, so called from a mode 
 practised at Artois, in France, in 
 boring for water. 
 
 Arthur's oven : According to the tes- 
 timony of Boethius, we had a spe- 
 cimen of one of the Roman temples 
 in Britain, built in the time of Ves- 
 pasian, remaining in that singular 
 little structure called Arthur's oven, 
 not far from the Wall of Antoninus. 
 He says, according to tradition, 
 there was an inscription on a stone 
 declaring that the building was 
 erected by Vespasian, in honour of 
 the Emperor Claudius and the God- 
 dess Victory. It had a tessellated 
 pavement. It was 19 feet 6 inches 
 in diameter within, arched towards 
 the top, with around aperture (like 
 that of the Pantheon at Rome) in 
 the midst of the dome 11 feet 6 
 inches diameter, and the utmost 
 height to the periphery, or edge of 
 this aperture, from the floor, 22 feet 
 {query, within or without, i. e. the 
 lowest or highest periphery of the 
 aperture ?). 
 
 At a little distance from the top, 
 beneath the circular opening in 
 the midst of the dome, was a small 
 square window on one side, and 
 round the inside, resting on the 
 floor, were stone seats, and against 
 the wall on the south side an altar ; 
 the door of entrance, which had a 
 
ART 
 
 ARTIFICER. 
 
 ASS 
 
 regular Roman arch, being placed 
 under the square window. 
 
 Arthur's oven was pulled down 
 about 1743, by Sir Michael Bruce 
 of Stonehouse, near Falkirk, for 
 the sake of the stones ; but with 
 little profit to himself, for the stones 
 were used in constructing a mill- 
 dam, which was soon carried away 
 by a flood. See the ' Antiquarian 
 Repertory,' vol. iii. p. 73; also Pen- 
 nant's ' Tour in Scotland,' pt. i. 
 p. 242, and pt. ii. p. 228; and 
 General Roy's ' Military Antiqui- 
 ties,' pi. 36 ; and Gordon's ' Itin. 
 Septentr.,' p. 24, tab. 
 
 Few Roman arches existing in 
 Britain, few, it appears probable, 
 were ever erected in it by that 
 people, and those of no great mag- 
 nificence, the arch was probably 
 a recent invention when the Ro- 
 mans had possession of this island. 
 
 Artificer, one who possesses a supe- 
 rior knowledge as an artist or ma- 
 nufacturer. 
 
 Asarotum, a kind of chequered pave- 
 ment used by the Romans. 
 
 Ash, a superior wood, of British 
 growth, of a brownish white with 
 a shade of green : it is tough and 
 elastic, and superior to any other 
 wood exposed to sudden shocks 
 and strains ; used for frames of 
 machines, wheel carriages, inside 
 work of furniture, etc. 
 
 Asheley (Hector), a famous master 
 mason in the times of Henry VII. 
 and VIII. 
 
 Ashlar, a term applied to common or 
 freestones as they come out of the 
 quarry. By ashlar is also meant 
 the facing of squared stones on the 
 front of a building : if the work be 
 so smoothed as to take out the 
 marks of the tools by which the 
 stones were first cut, it is called 
 plane ashlar; if figured, tooled ash- 
 lar, or random tooled, or chiselled, 
 or bousted, or pointed: if the stones 
 project from the joints, it is said to 
 be rusticated. 
 
 Ashlar, or Aehelor, hewn stone, used 
 for the facings of walls. 
 
 Ashlering, in carpentry, the fixing ol 
 short upright quarterings between 
 the rafters and the floor. 
 
 Ash-pan, in locomotive engines, an 
 iron box, open to the front only, 
 attached to the fire-box to receive 
 the ashes from the fire. 
 
 Ashpitel (W. H.), architect and en- 
 gineer, born in 1776, was exten- 
 sively employed in some very im- 
 portant public works : his reputa- 
 tion was of a dignified character ; 
 he died 20th April, 1852. His 
 son, now in practice, is of equal 
 merit. 
 
 ' 'Aspect, in architecture, the front si- 
 tuation of a building, or direction 
 towards any point. 
 
 Asphalt, native bitumen used with 
 pitch as a substitute for pave- 
 ment. 
 
 Asphaltum, a bituminous substance, 
 used for pavements and as a build- 
 ing material. 
 
 Asphaltum, called also Bitumen, 
 Mineral Pitch, etc. ; it is a resinous 
 substance rendered brown by the 
 action of the fire, natural or artifi- 
 cial. The substances employed in 
 painting under this name are the 
 residua of the distillation of various 
 resinous and bituminous matters 
 in preparing their essential oils, 
 and are all black and glossy like 
 common pitch, which differs from 
 them only in having been less 
 acted upon by fire, and in their 
 being softer. Asphaltum is prin- 
 cipally used in oil-painting: for 
 which purpose it is first dissolved 
 in oil of turpentine, by which it is 
 fitted for glazing and shading. Its 
 fine brown colour and perfect 
 transparency are lures to its free 
 use with many artists, notwith- 
 standing the certain destruction 
 which awaits the work on which 
 it is much employed, owing to its 
 disposition to contract and crack 
 from changes of temperature and 
 the atmosphere. 
 
 Assay, to examine and prove metals. 
 
 Assay balance, a very accurate ba- 
 lance, used in determining the 
 
 27 
 
 c2 
 
ASS 
 
 ASSURANCE. 
 
 ASS 
 
 exact weights of very smftll 
 bodies. 
 
 Assaying, ascertaining the qualities 
 of gold and silver with respect to 
 .* their purity. 
 
 /Assemblage, in carpentry and joinery, 
 framing, dovetailing, etc. 
 
 Assemblage of the Orders, in archi- 
 tecture, the placing of columns 
 upon one another in the several 
 ranges. 
 
 Assembly room, the room or suite of 
 rooms appropriated to the recep- 
 tion of large parties, for balls, etc. 
 ; Asser, a term used by Vitruvius for a 
 rafter, carrying the tile of a roof. 
 
 Asserts, small rafters immediately 
 beneath the tiles of a roof. 
 
 Assize Court, an edifice erected for 
 the accommodation of the officials 
 and the public at the sessions of 
 the judges of the superior courts. 
 
 Assula or Astula, chippings of blocks 
 of stone, small marble slabs. 
 
 Assurance, or Insurance, a contract 
 to make good a loss. 
 
 Assurance Companies, or Societies, 
 afford protection to persons from 
 the chances or hazards to which 
 their property or interests may be 
 exposed. 
 
 Assurance on human life is a con- ! 
 tract by which a certain amount of j 
 capital is secured at the expiration ! 
 of a stipulated period, either by ' 
 the payment of a specified sum at 
 the time of effecting the assurance, 
 or by the annual payment of a 
 smaller amount, according to the 
 age of a person whose life is as- 
 sured. 
 
 A person, with the view of secu- 
 ring a certain sum of money to 
 his family after his death, desires to 
 effect an assurance, either for a 
 determinate period, as one, three, 
 five, seven, ten, or more years, or 
 for the whole term of his life. In 
 the first case, if the person whose 
 life is assured, die before the expi- 
 ration of the term specified in the 
 policy, his inheritors receive the 
 amount for which the assurance ! 
 has been effected ; but, if the as- | 
 
 sured live beyond that period, they 
 receive nothing, and the assurer 
 reaps the advantage of the contin- 
 gency. In the latter case, that 
 is, by assurance for the whole term 
 of life, the inheritors are entitled 
 to receive the amount named in 
 the policy, upon proof of the death 
 of the person whose life has been 
 assured. To prevent the forfei- 
 ture of the policy, it is in all cases 
 essentially important that the con- 
 ditions upon which it has been 
 granted be strictly complied with. 
 The calculation as to the amount 
 of premium should be made ac- 
 cording to mathematical expecta- 
 tion, that is, equitably as to both 
 parties, allowing a fair rate of pro- 
 fit to the party granting the assu- 
 rance. If the terms for assuring 
 100 be required, for one year, 
 the probability must depend on the 
 age of the person whose life is pro- 
 posed to be assured ; and in equity 
 the sum to be paid should be equal 
 to the value of the expectation, 
 multiplied by the probability of its 
 being obtained. Should the age of 
 the person be 40 years, the proba- 
 bility of death in the course of the 
 year will be, according to the ta- 
 bles of mortality generally adopted, 
 dHifTj an( l tn * s fr act i n > multi- 
 plied by 100, gives the price of the 
 assurance, namely, 174 nearly. 
 The result, according to the tables 
 of mortality used in France, is 
 1-89. This is the rate charged by 
 the General Assurance Company ' 
 established at Brussels; but the 
 ' Belgic and Strangers' Union So- 
 ciety' charges at the rate of T87. 
 Both societies adopt Dubillard's 
 table of mortality, which is depo- 
 sited in the Bureau of Longitude in 
 Paris. 
 
 The profit to the assurer thus ap- 
 pears to be reduced to the interest 
 on the sum paid by the assured ; 
 but persons in health being alone 
 accepted, the chance of profit 
 thereby becomes considerable. For 
 a longer term than one year, the 
 
ASS 
 
 ATTACAMITE. 
 
 ATM 
 
 calculations are made on an esti- 
 mate of the probable amount of 
 interest derivable from the pre- 
 mium paid by the assurer. 
 
 Assynt marble, a white and greyish- 
 white British marble, found in 
 Sutherlandshire. 
 
 Astel, in mining, a board or plank, 
 an arch or ceiling of boards, over 
 the men's heads in a mine, to pro- 
 tect them. 
 
 Astragal, a small moulding, whose 
 contour is circular, at the neck of 
 the shafts of columns, next the apo- 
 physes : it also occurs in the base 
 of Ionic columns, and below the 
 fasciae of the Corinthian epistylium. 
 
 Astralish (mining), is that ore of 
 gold which lies as yet in its first 
 state or condition. 
 
 Assyrian Architecture, of the period 
 of Nineveh and the lower dynas- 
 ties, see examples of style in the 
 British Museum. 
 
 Astronomy, a mixed mathematical 
 science, which treats of the hea- 
 venly bodies, their motions, pe- 
 riods, eclipses, magnitudes, etc., 
 and of the causes on which they 
 depend: the knowledge of astro- 
 nomy is essential in navigation 
 and in measuring the earth's sur- 
 face : the diameter of this, the 
 third planet in the system, is 7924 
 miles and 7 furlongs. 
 
 Astylar, a term which expresses the 
 absence of columns or pilasters, 
 where they might otherwise be 
 supposed to occur. 
 
 Astyllen, in mining, a small ward or 
 stoppage in an adit or mine, to pre- 
 vent the free and full passage of 
 water, by damming up. 
 
 Asylum, in the Greek States, the tem- 
 ples, altars, sacred groves, and 
 statues of the gods ; a place pro- 
 vided for the protection of debtors 
 and criminals who fled for refuge. 
 
 Atacamite, prismatoidal green mala- 
 chite, a native muriate of copper. 
 
 Athanor, an ancient term for a metal 
 furnace. 
 
 Athenaeum, a school founded by the 
 Emperor Hadrian, at Rome, for the 
 
 promotion of literary and scientific 
 studies. 
 
 Athwart -hawse, the situation of a 
 ship when driven by the wind or 
 tide across the fore-part of another. 
 
 ^Atlantes, in architecture, male figures; 
 used similarly to the female Carya- 
 tides, in place of columns. 
 
 Atmosphere, the invisible elastic fluid 
 which surrounds the earth to an 
 unknown (exact) height, and par- 
 takes of all its motions ; the con- 
 stituent parts are air, water, car- 
 bonic acid gas, and unknown 
 bodies. The atmosphere is mea- 
 sured by a column of mercury of 
 29-922 inches, which has been 
 adopted in France as the mean 
 height of the barometer at the 
 surface of the sea. 
 
 Atmospheric currents, in high lati- 
 tudes, when undisturbed, are west- 
 erly, particularly in the winter sea- 
 son. If storms and gales revolve 
 by a fixed law, and we are able, by 
 studying these disturbing causes of 
 the usual atmospheric currents, to 
 distinguish revolving gales, it is 
 likely that voyages may be short- 
 ened. The indications of a revolv- 
 ing gale are, a descending barome- 
 ter, and a regularly veering wind. 
 
 Atmospheric engine, an engine in 
 which the steam is admitted only 
 to the under side of the piston 
 for the up-stroke ; it is then con- 
 densed, and the top of the cylinder 
 being open, the down-stroke is 
 caused by the pressure of the at- 
 mosphere. Marine engines on this 
 principle have three cylinders con- 
 nected to one crank-shaft, to ob- 
 tain uniformity of motion. 
 
 Atmospheric raihvay. The conclu- 
 sions drawn by Mr. R. Stephenson 
 are as follows : 1st, That the atmo- 
 spheric system is not an economical 
 mode of transmitting power, and 
 inferior in this respect both to loco- 
 motive engines and stationary en- 
 gines with ropes. 2ndly, That it is 
 not calculated practically to ac- 
 quire and maintain higher veloci- 
 ties than are comprised in the pre- 
 
ATM 
 
 ATMOSPHERE. 
 
 ATT 
 
 sent working of locomotive en- 
 gines. 3rdly, That it would not, in 
 the majority of instances, produce 
 economy in the original construc- 
 tion of railways, and in many 
 would most materially augment 
 their cost. 4thly, That on some 
 short railways, where the traffic 
 is large, admitting of trains of mo- 
 derate weight, but requiring high 
 velocities and frequent departures, 
 and where the face of the country 
 is such as to preclude the use of 
 gradients suitable for locomotive 
 engines, the atmospheric system 
 would prove the most eligible. 
 5thly, That on short lines of rail- 
 way, say four or fivo miles in 
 length, in the vicinity of large 
 towns, where frequent and rapid 
 communication is required between 
 the termini alone, the atmospheric 
 system might be advantageously 
 applied. 6thly, That on short 
 lines, such as the Blackwall Rail- 
 way, where the traffic is chiefly 
 derived from intermediate points, 
 requiring frequent stoppages be- 
 tween the termini, the atmospheric 
 system is inapplicable, being much 
 inferior to the plan of disconnect- 
 ing the carriages from a rope, for 
 the accommodation of the inter- 
 mediate traffic. 7thly, That on 
 long lines of railway, the requisites 
 of a large traffic cannot be attained 
 by so inflexible a system as the 
 atmospheric, in which the efficient 
 operation of the whole depends so 
 completely upon the perfect per- 
 formance of each individual section 
 of the machinery. 
 
 Atmospheric vapour. Deluc proves 
 the amount of force and vapour in 
 a vacuum of any given dimensions 
 is equal to its force and quantity 
 in an equal volume of air at the 
 same temperature, or that the tem- 
 perature of the air will determine 
 the force and quantity of vapour 
 held in it. M. le Roi, however, 
 first observed the temperature at 
 which dew commences to be de- 
 posited, as a rule of ascertaining 
 
 the moisture of the atmosphere. 
 Dr. Dalton investigated the force 
 of vapour of every temperature, 
 from zero to the boiling-point of 
 water (Fahrenheit), and expressed 
 this force by the weight of the 
 mercurial column it could support 
 in the tube of the barometer. 
 Dalton and Le Roi find the clear 
 point by pouring cold water into a 
 glass, and marking the temperature 
 at which it just ceases to deposit 
 dew on the sides of the glass in 
 the open air. The temperature 
 here observed is the point at which 
 dew would begin to be formed. 
 From this Dalton infers not only 
 the force exerted by the vapour, 
 but also its amount in a perpen- 
 dicular column of the whole atmo- 
 sphere, and likewise the force of 
 evaporation at the time of obser- 
 vation. 
 
 Atomic weights, or atoms, are the 
 quantities in which the different 
 objects of chemistry, simple or 
 compound, combine with each 
 other, referred to a common body, 
 taken as unity. 
 
 Atr amentum, a dye made of soot 
 mixed with burnt resin or pitch, 
 used by the ancients, particularly 
 by painters ; used also as a varnish. 
 
 Atrium, a term applied by the Ro- 
 mans to a particular part of a pri- 
 vate house : the court or hall of a 
 Greek or Roman house entered 
 immediately from the fauces of the 
 vestibulum. 
 
 Altai, Attle, Adall, Addle, in mining, 
 corrupt, impure off-casts, found in 
 the working of mines. 
 
 Attic base, the base of a column of 
 upper and lower torus, a scotia, 
 and fillets between them. 
 
 Attic Order, a low order of architec- 
 ture, used over a principal order, 
 never with columns, but with antfe 
 or small pilasters. 
 
 Attics should not be less than one- 
 quarter nor more than one-third 
 of the order they surmount : they 
 are frequently decorated with small 
 short pilasters, whose breadth 
 
ATT 
 
 AVILOR. 
 
 AXI 
 
 ought to be equal to the upper 
 diameter of the column underneath 
 them, and their projection usually 
 not more than one-quarter of their 
 breadth. 
 
 Attic story, the upper story of a house 
 when the ceiling is square with 
 the sides, by which it is distin- 
 guished from a common garret. 
 
 Atticurgus, a term applied by Vitru- 
 vius to the base of a column, which 
 he describes as divided by a scotia 
 or trochilus, with a fillet above 
 and below, and beneath all a plinth. 
 
 Attle, in mining, rubbish, deads, re- 
 fuse, or stony matter. 
 
 Attributes, in architecture, symbols 
 given to figures, or disposed as 
 ornaments on a building, to indi- 
 cate a distinguished character. 
 
 Attrition, the rubbing of bodies one 
 against another, so as to destroy 
 their surfaces. 
 
 Auditorium, an apartment in monas- 
 teries for the reception of strangers ; 
 also, a place where the Roman ora- 
 tors and poets recited their com- 
 positions. 
 
 Auger, a tool for boring large holes ; 
 it consists of a wooden handle, ter- 
 minated at the bottom with steel. 
 
 Aula, an area or open place ; in ancient 
 Roman architecture, a court or hall. 
 
 Auleolum, a small church or chapel. 
 
 Aureola, a crown of glory, given by 
 statuaries, etc., to saints, etc., to 
 denote the victory they have ob- 
 tained. 
 
 Aurificina, a place for melting and 
 refining gold, etc. 
 
 Aurum, anciently, gold. 
 
 Automaton, an apparently self-acting 
 machine, constructed of weights, 
 levers, pulleys, and springs, by 
 means of which it continues in 
 motion for a definite period. 
 
 Autometer, an instrument to measure 
 the quantity of moisture. 
 
 Auxiliary, or cushion rafter, a term 
 applied to the raking-piece of the 
 truss in a green post. 
 
 Aidant mure, an outward wall. 
 
 Avenue, a passage from one part of 
 a building to another. 
 
 Aviary, an apartment or building for 
 the keeping of birds. 
 
 Avilor (A. C. d'), architect, born in 
 Paris in 1653. The companion 
 with Desgodotz as travelling pupil 
 to Rome in 1674 : both were cap- 
 tured by Tunisian corsairs ; at Tunis 
 Avilor designed and executed a 
 mosque; was ransomed in 1676: 
 published several works, principally 
 of the styles of Louis XIV. and 
 Louis XV. : died in 1700. 
 
 Avolta, a place vaulted or arched over. 
 
 A-weather, a term applied to the 
 helm of a ship when it is put in 
 the direction from which the wind 
 blows. 
 
 Awning, a covering of canvas over the 
 the deck of a vessel, or over a boat, 
 as shelter from the sun or rain. 
 
 Axal section, a section through the 
 axis of a body. 
 
 Axes, the timbers of a roof which 
 form two sides of a triangle, the 
 tignum being the base : more gene- 
 rally termed Principals. 
 
 Axe, or broad axe, a tool used in 
 hewing timber. 
 
 Axiom, a self-evident truth. 
 
 Axis, in architecture, an imaginary 
 line through the centre of a column, 
 etc., or its geometrical representa- 
 tion : where different members are 
 placed over each other, so that the 
 same vertical line, on the elevation, 
 divides them equally, they are said 
 to be on the same axis, although 
 they may be on different planes : 
 thus, triglyphs and modillions are 
 so arranged, that one coincides with 
 the axis or line of axis of each co- 
 lumn : in like manner, the windows 
 or other openings in the several 
 stories of a fafade must all be in 
 the same respective axis, whethei 
 they are all of the same breadth 
 or not. 
 
 Axis, in geometry, the straight line 
 in a plane figure, about which it 
 revolves to produce or generate a 
 solid. 
 
 Axis, in mechanics : the axis of a 
 balance is the line upon which it 
 moves Ot* turns. 
 
AXI 
 
 AXLE. 
 
 AZU 
 
 Axis, in turning, an imaginary lifle 
 passing longitudinally through the 
 middle of the body to be turned, 
 from one point to the other of the 
 two cones, by which the work is 
 suspended, or between the back 
 centre and the centre of the collar 
 of the puppet which supports the 
 end of the mandril at the chuck. 
 
 Axis of a circle or sphere, any line 
 drawn through the centre, and ter- 
 minated at the circumference on 
 both sides. 
 
 Axis of a cone, the line from the ver- 
 tex to the centre of the base. 
 
 Axis of a cylinder, the line from the 
 centre of the one end to that of 
 the other. 
 
 Axis in peritrochio, a wheel and axle, 
 one of the five mechanical powers, 
 or simple machines; contrived 
 chiefly for the raising of weights 
 to a considerable height, as water 
 from a well, etc. 
 
 Axis of rotation, of any solid, the 
 line about which the body really 
 revolves when it is put in motion. 
 
 Axle bearing, in locomotive engines, 
 the gun-metal, or other metal bear- 
 ing, under which the axle journal 
 revolves : it is nicely fitted to the 
 journal, and lubricated by a si- 
 phon, to reduce, as far as practi- 
 cable, the friction on the journal. 
 
 Axle, in locomotive engines, journal, 
 or neck, the part of the axle turned 
 and polished for revolving in the 
 axle-box bearing. 
 
 Axle, leading, in locomotive engines, 
 the front axle of the engine : eight- 
 wheeled engines have two axles in 
 front of the driving wheel axle, and 
 they are often called leading axles. 
 
 Axle, trailing, the last axle of the en- 
 gine, usually placed under the foot- 
 plate: in Stephenson's and Cramp- 
 ton's patent engines, the driving 
 wheel axle is the last axle. 
 
 Axles, in locomotive engines, the iron 
 shafts supporting the engine, and 
 on which the wheels are fixed. 
 
 Axles, driving wheel, in locomotive 
 engines, with inside cylinders, this 
 is a cranked axle; with outside 
 
 cylinders, it is a straight axle ; it 
 is called the driving axle because 
 the connecting-rods and eccentric- 
 rods connect this axle to the pis- 
 tons, slide-valves, and pumps, and 
 by converting the rectilinear mo- 
 tion of the piston into a rotatory 
 one, it propels or drives the engine 
 in the direction required. 
 
 Axle-box, in locomotive engines, the 
 box (usually cast iron) fitted up 
 with a metal bearing in it, which 
 rests upon the polished part of the 
 axle. 
 
 Axle-box cover, in locomotive en- 
 gines, the plate of iron (usually 
 lined with leather) fitted to the 
 top of the axle-box to keep the oil 
 clean, and also from shaking out 
 by the motion of the engine. 
 
 Axle-box siphon, in locomotive en- 
 gines, the small tubes fitted into 
 the top of the axle-box for feeding 
 oil on to the axle journal as it re- 
 volves : the oil is fed by a piece of 
 cotton or worsted, having one end 
 introduced into these pipes, and 
 the other end lying down amongst 
 the oil in the axle-box. 
 
 Axle-guards, or horn-plates, in loco- 
 motive engines, the parts of the 
 frame in which the axle-box slides 
 up and down, as acted upon by 
 the springs. 
 
 Axle-guard stays, in locomotive en- 
 gines, the iron rods bolted to the 
 frame and to all the ends of the 
 j axle-guards, to strengthen them. 
 
 Azimuth compass, an instrument used 
 at sea for finding the sun's magne- 
 tic azimuth. 
 
 Azimuth dial, a dial of which the 
 style or gnomon is perpendicular 
 to the plane of the horizon 
 
 Azote, called also Nitrogen, a gas 
 which forms an important consti- 
 tuent of atmospheric air, etc., but 
 which, when breathed alone, de- 
 stroys life. 
 
 Azure, blue colour ; in painting, a 
 bright and florid tint of blue, equal 
 in force to ultramarine with the 
 addition of a little white. 
 
BAB 
 
 BABEL. 
 
 BAG 
 
 BABEL, Tower of, built by the poste- 
 rity of Noah, after the Flood ; re- 
 markable for its great height, and 
 for the disappointment of the 
 builders by the confusion of their 
 language. It was erected in the plain 
 of Shinar, upon the banks of the 
 great river Euphrates, and near the 
 place where the famous city of Ba- 
 bylon subsequently stood. " Let us 
 build us a city and a tower whose 
 top may reach unto heaven." Gen. 
 xi. 4. " The name of it is called 
 Babel, because the Lord did there 
 confound the language of all the 
 earth, and from thence did the 
 Lord scatter them abroad upon the 
 face of all the earth." Ib. xi. 9. 
 
 Babylonian architecture takes its ap- 
 pellation from the magnificence and 
 extent of the public buildings of 
 Babylon. This city was founded 
 by Nimrod about 1665 years before 
 Christ: its walls were fifty cubits 
 thick and 200 in height, built of 
 bricks made from the earth dug 
 out of the ditch that surrounded 
 the city. In the walls were 100 
 gates made of brass ; the jambs 
 and lintels were made of the same 
 metal. 
 
 Babylonian engine. An engine, to 
 raise water from the Euphrates to 
 supply the hanging gardens of Ba- 
 bylon, was constructed and used in 
 this the most ancient and splendid 
 city of the early age, founded by 
 the builders of Babel and enlarged 
 by Nimrod, extended and beauti- 
 fied by Semiramis. This engine 
 greatly exceeded in the pei'pendi- 
 cular the height to which the 
 water was elevated by it. Extensive 
 terraces were formed one above 
 another to the top of the city 
 walls ; and to supply them with 
 the necessary moisture, the engine 
 was erected, of which no account 
 is known at the present time. 
 
 Bac, in navigation, a praam or ferry- 
 boat. 
 
 Bac, in brewing, a cooler. 
 
 Baccalaureus, an ecclesiastical appa- 
 ritor or verger, who carries a staff 
 of office. 
 
 Bacca, a light-house, watch-tower, or 
 beacon. 
 
 Baccharis, ploughman's spikenard. 
 
 Baccio della Porta, called Fra Barto- 
 lommeo, born 1469 ; of the Floren- 
 tine school ; he taught the use of 
 the lay figure. 
 
 Back, the back of a lode is the part 
 of it nearest the surface ; the back 
 of a level is that part of the lode 
 extending above it to within a 
 short distance of the level above. 
 
 Back-board, in turning, that part of 
 the lathe which is sustained by the 
 four legs, and which sustains the 
 pillars that support the puppet- 
 bar : the back-board is only used 
 in the best constructed lathes. 
 
 Back centre screw, the screw for set- 
 ting up the back centre of a lathe, 
 to the work to be turned, after the 
 puppet-head has been fixed. 
 
 Backed, a sea phrase, to back an an- 
 chor, to carry out a smaller one 
 ahead of the one by which the ves- 
 sel rides, to take off some of the 
 strain. 
 
 Background, in painting, is the space 
 of ground behind the principal ob- 
 jects of the picture. 
 
 Back joint, applied by masons to a 
 rebate such as that made on the 
 inner side of the jamb of a chimney- 
 piece to receive a slip. 
 
 Back-links, the links in a parallel mo- 
 tion which connect the air-pump 
 rod to the beam. 
 
 Back of a hip, in carpentry, is the 
 upper edge of a rafter between two 
 sides of a hipped roof, formed to an 
 angle, so as to range with the raft- 
 ers on each side of it. 
 
 Back of a ivindouf, the board or wain- 
 scoting between the sash-frames 
 and the floor, uniting with the two 
 elbows in the same plane with the 
 shutters : when framed it is com- 
 
BAG 
 
 BAKEHOUSE. 
 
 BAL 
 
 monly with single panels, wifti 
 mouldings on the framing corre- 
 sponding with the doors, shutters, 
 etc., in the apartment in which it 
 is fixed. 
 
 Back-painting, the art of painting 
 mezzotinto prints, on plate or 
 crown glass, with oil colours. 
 
 Backs, in carpentry, the principal 
 rafters of a roof. 
 
 Back-staff, an instrument nvented by 
 Capt. Davis for a sea quadrant, so 
 named because the back of the ob- 
 server is turned towards the sun 
 when using it. 
 
 Back-stays, long ropes from the top- 
 mast heads to both sides of the 
 ship, where they are extended to 
 the channels. 
 
 Back-stay stool, a short piece of plank 
 fitted for the security of the dead- 
 eyes and chains for the backstays, 
 though sometimes the channels are 
 left long enough at the after end 
 for the back-stays to be fitted 
 thereto. 
 
 Bac-maker, a cooper who makes 
 liquor-bacs, etc. 
 
 Baculometry, the art of measuring 
 either accessible or inaccessible 
 distances or lines, by the help of 
 baculi, staves, or rods. 
 
 Baculus, a branch of hazel, used for 
 the discovery of mines, springs, 
 etc. 
 
 Badigeon, in statuary, a mixture of 
 plaster and freestone sifted and 
 ground together, used by statuaries 
 to repair defects in their work. 
 
 Baguette, a small moulding, like the 
 astragal : when enriched with foli- 
 age, it is called a chaplet ; when 
 plain, a head. 
 
 Bagnio, a bath. 
 
 Bagpipe. To bagpipe the mizen is 
 to lay it aback by bringing the 
 sheet to the weather-mizen rig- 
 ging- 
 
 Bailey, an area of ground, a court, 
 within the walls of a fortress ; 
 in modern acceptation, frequently 
 applied to a prison. 
 
 Baird (Mr.), in 1816, constructed a 
 steamboat in St. Petersburg. 
 
 Bakehouse, an apartment with an 
 oven to bake bread. 
 
 Baker's central rule for the construc- 
 tion of equations, is a method of 
 constructing all equations not ex- 
 ceeding the fourth degree. 
 
 Bal, a term used in mining. 
 
 Balance, Hydrostatic, an instrument 
 which determines the specific gra- 
 vity of fluids and solids by weigh- 
 ing them in water. 
 
 Balance, or equilibrium, in a picture, 
 is when the forms of objects, the 
 lights, shades, colours, and expres- 
 sions, are happily adapted to each 
 other, and no one figure or colour 
 overpowers or obscures the rest. 
 When a building is seen in one 
 corner of a picture, it is frequently 
 balanced by something in the other; 
 even a large bird will produce the 
 effect. 
 
 Balance, one of the six simple powers 
 in mechanics, chiefly used in de- 
 termining the equality or differ- 
 ence in heavy bodies, and conse- 
 quently their masses or quantities 
 of matter. Balances of various 
 kinds are commonly used as the 
 common balance, the bent lever 
 balance, the Roman balance, and 
 the Swedish or Danish balance 
 for the adjustment of differences in 
 weights, etc. 
 
 Balance, in hydrostatics, an instru- 
 ment for determining the specific 
 gravity of bodies. 
 
 Balance (The) of a clock or watch, 
 the part which, by the regularity 
 of its motion, determines the beat 
 or strike. 
 
 Balance-gates, in hydraulic engineer- 
 ing, may be described by referring 
 to those made for the Compensation 
 Reservoir of the East London Wa- 
 ter-works. These gates were de- 
 signed for the purpose of discharg- 
 ing the body of water collected in 
 the reservoir during the rise of the 
 tide, in order to supply the mills 
 lower down the river Lea, which 
 might otherwise have been injured 
 by the amount withdrawn from the 
 river by the pumping-engines of 
 
BAL 
 
 BALL. 
 
 BAL 
 
 the Water Company. They differ 
 in construction from common 
 flood-gates, being made to work 
 upon a vertical shaft or spindle as 
 a centre, and having an equal sur- 
 face of gate on each side of that 
 centre ; so that whatever pressure 
 of water there may be on one side 
 of the gate tending to force it open, 
 there is as great a pressure on the 
 opposite leaf to keep it shut. 
 
 Balance-reef, a reef in a spanker or 
 fore-aft mainsail, which runs from 
 the outer head caving diagonally to 
 the tack ; it is the closest reef, and 
 makes the sail triangular. 
 
 Balastre, the finest gold-cloth, manu- 
 factured at Vienna. 
 ! Balcony, a projection in the front of a 
 house or other building, supported 
 by consoles or columns, sometimes 
 applied to the interiors of theatres, 
 and for public convenience in large 
 buildings. 
 
 Balcony, the projecting gallery in the 
 stern of large ships. 
 
 Baldachin, a canopy supported by 
 columns, and raised over altars, 
 tombs, etc. 
 
 Baldachino, in architecture, an open 
 building supported by columns and 
 covered with a canopy, frequently 
 placed over an altar. 
 
 Bale : to bale a boat is to throw water 
 out of her. 
 
 Batista, in practical geometry, the 
 same as the geometrical cross, 
 called the Jacob's staff. 
 
 Balistic pendulum, an instrument 
 used for measuring the velocity of 
 a cannon-ball, i.e. the force of gun- 
 powder. It consists, in its simplest 
 form, of a beam which can swing 
 on a fixed axis at one end, while 
 the ball strikes the other end ; and 
 the angle through which that end 
 moves being known, the velocity 
 of the cannon-ball may be com- 
 puted. 
 
 Balistics, the art of throwing missive 
 weapons by means of an engine. 
 
 Balistraria, a room in fortified build- 
 ings, in which the crossbows were 
 deposited. 
 
 35 
 
 Balk, a great beam. 
 
 Ball, any spherical body, either na- 
 tural or artificial. 
 
 Ballast, for ships, the materials for 
 which are gravel, iron, or stone, or 
 any heavy substance, to stow away 
 in the hold, to bring a ship to a 
 proper water-line when unladen, 
 to counterbalance the effect of the 
 wind on the masts, and to give sta- 
 bility. 
 
 Ball-cock, a hollow globe of metal at- 
 tached to the end of a lever, which 
 turns the stop-cock of a cistern- 
 pipe by floating on the surface of 
 the water, thereby regulating the 
 supply. 
 
 Ball-flower, an ornament like a ball, 
 placed in a circular flower, the pe- 
 tals of which form a cap round it ; 
 it belongs to the decorated style of 
 the fourteenth century. 
 
 Ball-lever, a lever of metal having a. 
 ball affixed at one end as a weight, 
 which assists in closing again the 
 plug or valve of a cistern after it 
 has been pulled up to obtain a sup- 
 ply of water. 
 
 Ball of a pendulum, the weight at tne 
 bottom of it ; sometimes called the 
 bob. 
 
 Balister or Baluster, the lateral part 
 of a scroll in the capital of the 
 Ionic column; a little pillar-rail, 
 such as are on the outside of 
 cloisters. 
 
 Ball and socket, an instrument made 
 of brass, with a perpetual screw, so 
 as to move horizontally, vertically, 
 or obliquely : used for the managing 
 of surveying and astronomical in- 
 struments. 
 
 Ballon, is a round globe on the top 
 of a pillar. 
 
 Balloon or Baston, a mould at the 
 base of a column called a Tore. 
 
 Balloon, a spheroidal hollow body, 
 capable of floating in the air by 
 means of its inflation with gas spe- 
 cifically lighter than the air. 
 
 Balloon, a globe placed on the top of 
 a pillar or pediment, as an acroter 
 or crowning. 
 
 Balls, in electricity, are two pieces of 
 
BAL 
 
 BALUSTRADES. 
 
 BAN 
 
 cork or pith of elder-tree, nicety 
 turned in a lathe to the size of a 
 small pea, and suspended by means 
 of delicate threads, 
 
 Balk-staff, a quarter-staff. 
 
 Ball-valves, the valves in the force- 
 pumps of a locomotive engine : the 
 balls are turned and ground truly 
 spherical, so as to fit watertight 
 into the valve-seats in every posi- 
 tion. 
 
 Balneac, in Greek, signifies a bath or 
 bathing-vessel. 
 
 Balteum, a band or girdle, according 
 to Vitruvius : this word is used to 
 denote the moulding on the bolsters 
 or sides of the Ionic capital. 
 
 Baltei, the bands in the flanks of 
 Ionic pulvinated capitals. Balteum 
 and balteus were generally used by 
 the Romans to signify the belt by 
 which the sword or quiver was 
 suspended. 
 
 Baluster, a small column or pillar 
 used in a balustrade. Balusters are 
 generally placed round the gallery 
 in the stern and the quarter gallery 
 of large ships. 
 
 Balustrade, a series or row of balus- 
 ters, joined by a rail, serving for a 
 rest to the arms, or as a fence or 
 enclosure to balconies, altars, stair- 
 cases, etc. 
 
 Balustrades, when intended for use, 
 as against windows, on flights of 
 steps, terraces, and the like, should 
 not be more than three feet six 
 inches, nor less than three feet in 
 height. When used for ornament, 
 as on the summit of a building, 
 their height may be from two- 
 thirds to four-fifths of the entabla- 
 ture whereon they are employed ; 
 and this proportion is to be taken 
 exclusive of their zoccolo or plinth, 
 so that from the proper point of 
 sight the whole balustrade may be 
 exposed to view. There are vari- 
 ous species of balusters ; if single- 
 bellied, the best way is to divide 
 the total height of the space al- 
 lotted for the balustrade into thir- 
 teen equal parts, the height of 
 the baluster to be eight, of the base 
 
 three, and of the cornice two of 
 those parts ; or divide the total 
 height into fourteen parts, making 
 the baluster eight, the base four, 
 and the cornice two. If double- 
 bellied, the height should be divi- 
 ded into fourteen parts, two of 
 which are to be given to the cor- 
 nice, three to the base, and the re- 
 mainder to the baluster. 
 
 The distance between two balus- 
 ters should not be more than half 
 the diameter of the baluster in its 
 thickest part, nor less than one- 
 third of it ; but on inclined planes 
 the intervals should not be quite so 
 wide. 
 
 Bancalia, cushions or coverings for 
 seats and benches. 
 
 Band, in architecture, denotes any flat 
 low member, or moulding, that is 
 broad and not very deep. 
 
 Banded column, a support which has 
 its body interrupted at intervals by 
 one or more broad projecting cinc- 
 tures, etc. 
 
 Bandle, an Irish measure of two fee 
 in length. 
 
 Bandlet, a small fillet, or flat mould- 
 ing. 
 
 Bandrol, a little flag or streamer 
 affixed to the top of masts. 
 
 Bank, a long piece of timber. 
 
 Bank, a carpenter's term for a piece 
 of fir-wood unslit, from 4 to 10 
 inches square, and of any length. 
 
 Bank : to double-bank an oar, is to 
 have it pulled by two men. 
 
 Banker (7%e),in bricklaying, a bench 
 from 6 to 12 feet in length, used 
 for preparing the bricks for gauged 
 work. 
 
 Banker, a cushion or covering for a 
 seat. 
 
 Banker browded, cushions embroid- 
 ered. 
 
 Banneret, anciently a knight made in 
 the field, with a ceremony of cut- 
 ting off the point of his standard 
 and making it as if it were a banner. 
 
 Banquet, the raised footway adjoin- 
 ing to the parapet on the sides of a 
 bridge. 
 Banqueting house or room, a house 
 
BAN 
 
 BAR IRON. 
 
 BAR 
 
 or room where public feasts are 
 given. 
 
 Bantam-work, painted or carved work, 
 resembling that of japan, only more 
 gaudy. 
 
 Baptaterium, a back-mill or fulling- 
 mill. 
 
 Baptistery, a place or edifice where 
 baptism is performed. A basin, 
 pool, or place for bathing. 
 
 Bar, a barrier, gatehouse : in law, a 
 place where counsellors plead. 
 
 Bar, a bank or shoal at the entrance 
 of a harbour. 
 
 Bar of ground, in mining, any course 
 of vein which runs across a lode, or 
 different from those in its vicinity. 
 
 Bar iron, long prismatic pieces of 
 iron, being rectangular parallelopi- 
 peds, prepared from pig iron, so as 
 to be malleable, for the use of black- 
 smiths for the method of joining 
 bars. 
 
 Barberry-wood is of small size, re- 
 sembling alder, and is straight and 
 tenacious. 
 
 Barbacan, or Barbican, in the middle 
 ages, a fort at the entrance of a 
 bridge, or the outlet of a city ; the 
 part of a fortress where watch and 
 ward was kept. 
 
 Barbacan, a long narrow canal or 
 passage for water in Wales, where 
 buildings are liable to be overflowed, 
 likewise to drain off water from a 
 terrace. 
 
 | Bar-master, among miners, the per- 
 son who keeps the gauge or dish for 
 measuring the ore. 
 
 J Bar of the port, a billet thrust through 
 the rings that serve to shut up the 
 portholes of a ship. 
 
 Barbarelli (Giorgio), of Castelfranco, 
 known by the name of Giorgione, 
 of the Venetian School of Painting. 
 He died in 1511, at the age of 34. 
 
 Barcella, a vessel containing incense. 
 
 Barcon, a luggage-vessel used in the 
 Mediterranean. 
 
 Bardiglione, a blue variety of anhy- 
 drite, cut and polished for orna- 
 mental purposes. 
 
 Bare poles, the condition of a ship 
 when she has no sail set. 
 
 37 
 
 Bari, the portion of a slate showing 
 the gauge, and on which the water 
 falls. 
 
 Barge, a large double-banked boat 
 used by the commander of a vessel 
 in the navy. 
 
 Barge-board, a front or facing to 
 conceal the barge couples, laths, 
 tiles, thatch, etc. Barge-boards 
 (or, more properly, verge-boards), 
 pendants, pinnacles, and brackets, 
 being the chief decorations of 
 houses in early domestic archi- 
 tecture, should always be made of 
 strong oak, and left to acquire by 
 age a grey hue ; and not of slight 
 deal, painted, as is now the too 
 frequent practice. 
 
 Barge-couple, in architecture, a beam 
 mortised into another, to strengthen 
 the building. 
 
 Barge-course, a part of the tiling or 
 thatching of a roof, projecting over 
 the gable, and filled up with boards, 
 mortar, etc. 
 
 Bargh-master, a surveyor of mines. 
 
 Bargmote, a court held concerning 
 the affairs of mines. 
 
 Barium, a metal that exists in the 
 sulphate and carbonate of barytes ; 
 found in nature in great abund- 
 ance. 
 
 Barker's mill, an hydraulic machine 
 much in use. 
 
 Barkery, a tan-house ; also a sheep- 
 cote. 
 
 Bark hert, a seat in large gardens, a 
 resting-place. 
 
 Barmkyn, the rampart or outer forti- 
 fication of a castle. 
 
 Barn, a covered farm-building for 
 laying up grain, hay, straw, etc. 
 
 Barnacle, a shellfish often found on 
 a vessel's bottom. 
 
 Barocci (Federigo), of the Roman 
 school, in the style of Correggio, a 
 style best calculated to reform an 
 age which had neglected the true 
 principles of art, particularly colour- 
 ing and chiaroscuro. 
 
 Barometer and Sympiesometer. The 
 barometer is a measure for the 
 weight of the atmosphere, or its 
 pressure on the surface of the globe. 
 
BAR 
 
 BAROMETER. 
 
 BAR 
 
 It is well known that it is owing 
 to the atmospheric pressure that 
 water rises in a common pump after 
 the air has been drawn from the 
 barrel, but that the height to which 
 it can be raised by this means is 
 limited, and does not much exceeds 
 30 feet. A little more than 30 feet 
 of water, therefore, balances the 
 atmosphere. Mercury being about 
 twelve times heavier than water, 
 about 30 inches of mercury will 
 also counterpoise the atmosphere. 
 The principle of the barometer is 
 simple. If a tube, about 3 feet 
 long, closed at one end and open at 
 the other, be filled with mercury, 
 and, with the open end stopped 
 by a finger, this tube be reversed, 
 and placed upright in a cup partly 
 filled with the same liquid, the 
 mercury in the tube, iu ordinary 
 states of the weather, will descend 
 to 30 inches, measured from the 
 surface of the fluid in the cup, and 
 not much lower. The mercury is 
 sustained in the tube by the pres- 
 sure of the atmosphere on the sur- 
 face of the fluid in the cup. Such 
 a tube and cup, so filled, would in 
 fact be a barometer ; and if a move- 
 able index were added to it, this 
 simple instrument would indicate 
 the changes which take place in the 
 atmospheric pressure. The Sympie- 
 someter is a more delicate instru- 
 ment for measuring the atmosphe- 
 ric pressure ; but it is also a more 
 complicated one than the mercurial 
 barometer, and it would be best un- 
 derstood by inspection. The upper 
 part of the tube contains hydrogen 
 gas, which is elastic ; and the lower 
 part, including the well, contains 
 oil. By this compound construc- 
 tion, whilst the length of the tube 
 is less than that of the mercurial 
 barometer, the index, or scale for 
 measuringthe pressure, is increased. 
 Hydrogen gas being very sensibly 
 affected by all changes of tempe- 
 rature, the index, by which the at- 
 mospheric pressure is read, requires 
 to be set according to the actual 
 
 temperature, before the atmospheric 
 pressure can be read off. 
 
 Since mercury expands by heat, 
 a correction for temperature is also 
 required for the mercurial barome- 
 ter, when exact calculations are to 
 be made ; and for this reason ba- 
 rometers usually have a thermome- 
 ter attached to them, in order that 
 the temperature may be read off, 
 and recorded at the same time that 
 the barometer is registered. 
 
 The atmosphere is supposed to 
 extend to about the height of 50 
 miles, and its density to diminish 
 from the surface of the globe up- 
 wards, in a geometrical ratio. 
 
 Thus, when observations are made 
 on land, above the level of the sea, 
 a correction is required for altitude, 
 since the weight of the atmosphere 
 diminishes as we ascend. It is 
 owing to this that we are enabled 
 to determine the height of moun- 
 tains by barometers, and that aero- 
 nauts compute the altitude to which 
 they ascend in balloons. 
 
 The cause of the oscillations of 
 the barometer in a gale of wind 
 was first explained by the late Mr. 
 Redfield, of New Yo'rk. A quan- 
 tity of fluid in a cup, put in rapid 
 circular motion, gives a represen- 
 tation of the form of that portion 
 of the atmosphere which is within 
 the limits of a storm. A whirlwind 
 which sets an extended portion of 
 the atmosphere in a state of rapid 
 revolution, diminishes the pressure 
 over a corresponding portion of the 
 earth's surface, and most of all at 
 the centre of the whirl, where the 
 depth of the compressing column 
 of air will be least. 
 
 The principle of the barometer 
 should be explained in all works 
 on navigation, and in all schools 
 where navigation is taught. 
 
 The following is a table for the 
 correction to be applied to the ob- 
 served height of the mercury, to 
 reduce it to the freezing point, at 
 32 Fahrenheit, or zero of the Cen- 
 tigrade scale. 
 
BAR BAROMETER. BAR 
 
 Reduction of the English Barometer to the Freezing Point, or to 32 on 
 
 Fahrenheit's Scale. Subtractive. (From Galbraith's Tables.} 
 
 
 
 PART I. For Mercury only. 
 
 PART n. Mercury and Brass 
 
 C 
 
 
 
 Temp. 
 
 Height of the Barom. in inches. 
 
 Height of the Barom. in Inches 
 
 2 
 
 
 
 Fah. 
 
 Cent. 
 
 28 In. 
 
 29 In. 
 
 30 In. 
 
 31 In. 
 
 28 In. 
 
 29 In. 
 
 30 In. 
 
 31 In. 
 
 fts 
 Q 
 
 
 
 
 
 32 
 
 
 
 o-oo 
 
 o-oooo 
 
 o-oooo 
 
 o-oooo 
 
 o-oooo 
 
 0-0088 
 
 0-0091 
 
 0-0094 
 
 0-0097 
 
 2 
 
 
 
 34 
 
 I'll 
 
 0-0056 
 
 0-0058 
 
 0-0060 
 
 0-0062 
 
 0-0138 
 
 0-0143 
 
 0-0148 
 
 0-0152 
 
 5 
 
 
 
 36 
 
 2'22 
 
 0-0112 
 
 0-0116 
 
 0-0120 
 
 0-0124 
 
 0-0188 
 
 0-0194 
 
 0-0201 
 
 0-0208 
 
 7 
 
 
 
 38 
 
 3-33 
 
 0-0168 
 
 0-0174 
 
 0-0180 
 
 0-0186 
 
 0-0238 
 
 0-0246 
 
 0-0255 
 
 0-0263 
 
 9 
 
 
 
 40 
 
 4-44 
 
 0-0224 
 
 0'0232 
 
 0-0240 
 
 0-0248 
 
 0-0288 
 
 0-0298 
 
 0-0309 
 
 0-0319 
 
 11 
 
 
 
 42 
 
 5'55 
 
 0-0280 
 
 0-0290 
 
 0-0300 
 
 0-0310 
 
 0-0338 
 
 0-0350 
 
 0-036-2 
 
 0-0374 
 
 12 
 
 
 
 44 
 
 666 
 
 0-0336 
 
 0-0348 
 
 0-0360 
 
 0-0372 
 
 0-0388 
 
 0402 
 
 0-0416 
 
 0-0430 
 
 14 
 
 
 
 46 
 
 777 
 
 0-0392 
 
 0'04 06 
 
 0-0420 
 
 0-0434 
 
 0-0438 
 
 0-0454 
 
 O'04/O 
 
 0485 
 
 16 
 
 
 
 48 
 
 8-88 
 
 0-0448 
 
 0-0464 
 
 0-0480 
 
 0-0496 
 
 0-0488 
 
 0-0506 
 
 0-0523 
 
 0-0541 
 
 17 
 
 
 
 50 
 
 lO'OO 
 
 0-0504 
 
 0-0522 
 
 0-0540 
 
 0-0558 
 
 0'0538 
 
 0-0558 
 
 0-0577 
 
 0-0596 
 
 19 
 
 
 
 52 
 
 11-11 
 
 0-0559 
 
 0-05/9 
 
 0-0599 
 
 0-0619 
 
 0-0588 
 
 o 0609 
 
 0-0630 
 
 0-0652 
 
 21 
 
 
 
 54 
 
 12-22 
 
 0-0615 
 
 0-0637 
 
 0-0659 
 
 0-0681 
 
 0-0638 
 
 0-0661 
 
 0-0684 
 
 0-0707 
 
 23 
 
 
 
 56 
 
 13-33 
 
 0-0671 
 
 0-0695 
 
 0-0719 
 
 0-0743 
 
 0-0688 
 
 0-0713 
 
 0-0738 
 
 0-0762 
 
 25 
 
 
 
 58 
 
 14-44 
 
 0-0727 
 
 0-0753 
 
 0-0779 
 
 0-0805 
 
 0-0/38 
 
 0'0765 
 
 0-0791 
 
 0-0818 
 
 26 
 
 
 
 60 
 
 15-55 
 
 0-0783 
 
 0-0811 
 
 0-0839 
 
 0-0867 
 
 0-0788 
 
 0-0817 
 
 0-0845 
 
 0-0873 
 
 28 
 
 
 
 62 
 
 16-66 
 
 0-0838 
 
 0-0868 
 
 0-0898 
 
 0-0928 
 
 0838 
 
 0-0868 
 
 0-0898 
 
 0-0928 
 
 30 
 
 
 
 64 
 
 1777 
 
 0-0894 
 
 0-0926 
 
 0-0958 
 
 0-0990 
 
 0888 
 
 0-09^0 
 
 0-0951 
 
 0-0983 
 
 32 
 
 
 
 66 
 
 18-88 
 
 0-OQ50 
 
 0-0984 
 
 0-1018 
 
 0-1051 
 
 0938 
 
 0-0971 
 
 0-1005 
 
 0-1039 
 
 34 
 
 
 
 68 
 
 20'CO 
 
 0-1005 
 
 0-1041 
 
 0-10/7 
 
 0-1113 
 
 0988 
 
 0-J023 
 
 0-1058 
 
 0-1094 
 
 36 
 
 
 
 70 
 
 21-11 
 
 0-1061 
 
 0-1099 
 
 0-1137 
 
 0-1175 
 
 1037 
 
 0-1075 
 
 0-1112 
 
 0-1149 
 
 38 
 
 
 
 72 
 
 22-22 
 
 1117 
 
 0-1156 
 
 1196 
 
 0-12.^6 
 
 1087 
 
 0-1126 
 
 0-1165 
 
 0-1204 
 
 40 
 
 
 
 74 
 
 23-33 
 
 11/2 
 
 0-1214 
 
 1256 
 
 0-1298 
 
 1137 
 
 0-1178 
 
 0-1218 
 
 0-1259 
 
 42 
 
 
 
 76 
 
 24-44 
 
 1228 
 
 0-12/1 
 
 1315 
 
 0-1359 
 
 1187 
 
 0-1229 
 
 0-1272 
 
 0-1314 
 
 44 
 
 
 
 78 
 
 25-55 
 
 1283 
 
 0-1329 
 
 1375 
 
 0-1421 
 
 1237 
 
 0-1281 
 
 0-1325 
 
 0-1369 
 
 45 
 
 
 
 80 
 
 2666 
 
 1339 
 
 0-1387 
 
 1434 
 
 0-1482 
 
 1286 
 
 0-1332 
 
 0-1378 
 
 1424 
 
 47 
 
 
 
 82 
 
 27-77 
 
 1394 
 
 0-1444 
 
 1494 
 
 0'1544 
 
 1336 
 
 0-1384 
 
 0-1432 
 
 1479 
 
 49 
 
 
 
 84 
 
 28-88 
 
 1450 
 
 0-1502 
 
 1553 
 
 0-1605 
 
 1386 
 
 0-1435 
 
 0-1485 
 
 1534 
 
 51 
 
 
 
 86 
 
 30-00 
 
 1505 
 
 0-1559 
 
 1613 
 
 0'1667 
 
 0-1435 
 
 0-1486 
 
 0-1538 
 
 1589 
 
 53 
 
 
 
 88 
 
 31-11 
 
 0-1561 
 
 0-1616 
 
 1672 
 
 0-1728 
 
 0-1485 
 
 0-1538 
 
 0-1501 
 
 1644 
 
 54 
 
 
 
 90 
 
 32-22 
 
 0-1617 
 
 0-1674 
 
 1731 
 
 0-1790 
 
 0-1535 
 
 0-1589 
 
 0-1644 
 
 1699 
 
 56 
 
 
 
 P. P. for 
 
 0. 4 0. 8 1. 2 1. 6 2. 
 
 0. 4 0. 8 1. 2 1. 6 2. 
 
 
 
 
 Temp- F- + 
 
 12 24 35 47 59 
 
 10 21 31 42 52 
 
 
 
 Baroscope, an instrument for finding 
 
 for retaining the water of that river 
 
 out the variations of the air, or 
 
 at a sufficient height to irrigate the 
 
 weather-glass. 
 
 summer crops. The dam consists of 
 
 Barouche, a coach without a roof. 
 
 a curved quay, 4,500 feet in length ; 
 
 Barozzi, otherwise Vignola, a dis- 
 
 and two sluice-gates are placed at 
 
 tinguished architect and painter, 
 
 the head of the Delta, one on the 
 
 born 1507, died in 1573. 
 
 Rosetta, the other on the Damietta 
 
 Barque, a three-masted vessel having 
 
 branch, at a distance of half a 
 
 her fore and main masts rigged like 
 
 league from each other. 
 
 a ship's, and her mizen-mast like 
 
 Barrel, in machinery, is a term ap- 
 
 the main-mast of a schooner, with 
 
 plied generally to anything hollow 
 
 no sail upon it but a spanker. 
 
 and cylindrical. 
 
 Barra, in the middle ages, a tower or 
 
 Barrow, in mining, a heap of dead 
 
 bar at one end of a bridge. 
 
 attle, rubbish, etc. 
 
 Barracks, buildings for the lodgment 
 
 Barrow, in salt-works, wicker cases 
 
 of soldiers. 
 
 almost in the shape of a sugar 
 
 Barrage, a mound or dyke to raise 
 
 loaf, in which the salt is put to 
 
 the waters of a river. One of the 
 
 drain. 
 
 most remarkable works of this 
 
 Barrows, or tumuli, monuments of 
 
 kind is the Barrage of the Nile, 
 
 the greatest antiquity, raised as se- 
 
 39 
 
BAR 
 
 BASE-COURT. 
 
 pulchres for the interment of the 
 great. 
 
 Barry (James), a painter, was born 
 in Cork, October 1741, and died in 
 the 65th year of his age. 
 
 Bars, straight pieces of timber or 
 metal that run across from one 
 part of a machine to another. 
 
 Bartholomeus (Alfred), architect, born 
 in 1801, published some excellent 
 works for study and use, died in 
 1844. 
 
 Partisan, a wooden tower; a turret 
 on the top of a house, castle, or 
 church tower ; a balcony or platform, 
 within a parapet on the roof of 
 any building ; in architecture, bar- 
 tisans are small overhanging turrets, 
 which project from the angles on 
 the top of a tower, or from the 
 parapet or other parts of a building. 
 
 Barton, the demesne lands of a manor, 
 a manor house ; the fields, a fold- 
 yard, or outhouse. 
 
 Barton house, a term used in the 
 southern and western counties to 
 express a farm-building, outhouse, 
 and appurtenances. 
 
 Bar wood, an African wood, in pieces 
 four to five feet long. It is used 
 as red dip-wood, also for violin 
 bows, ramrods, and in turning. 
 
 Barytes, a heavy mineral, found in 
 copper-mines, and formerly named 
 ' ponderous spar ; ' it has a caustic, 
 alkaline taste, and is extremely 
 poisonous. 
 
 Basalt, a variety of trap-rock, hard and 
 heavy, usually of a dark green or 
 brownish-black colour, composed 
 of augite and felspar, with some 
 iron and olivine ; it frequently oc- 
 curs in a columnar form. 
 
 Basanite, a variety of schistose horn- 
 stone, called also Lydian stone. 
 
 Bascule bridge, a bridge to lift, to ac- 
 commodate a passing for shipping. 
 
 Base of a figure, in geometry, denotes 
 the lowest part of its perimeter. 
 
 Base of a conic section is a right 
 line in the parabola and hyperbola 
 formed by the common intersection 
 of the cutting plane and the base 
 of the cone. 
 
 40 
 
 Base, in architecture, the lower pai 
 or member of a column, on whic 
 the shaft stands. 
 
 Base-court, the outer or lower yar 
 of a castle, appropriated to stable; 
 offices, etc. 
 
 Base-line, in perspective, the commo 
 section of a picture and the gee 
 metrical plane. 
 
 Base-line, in surveying, a line, mea 
 sured with the greatest possiol 
 exactness, on which a series of trl 
 angles are constructed, in order t 
 determine the position of object 
 and places. The measurement o 
 degrees of the meridian, for th 
 purpose of ascertaining the size o 
 the earth, has been undertaken ii 
 various countries, with extrenn 
 accuracy. The arc measured b; 
 the French extended from Dun 
 kirk to the southernmost point o 
 the Balearic Islands, including 
 120 22' 14", having its centn 
 halfway between the Equator anc 
 the North Pole. Another survej 
 of this kind was performed on 
 part of the shore of Pennsylvania 
 which happens to be so straight 
 and level as to admit of a line ol 
 more than ISOmilesbeingmeasured 
 directly without triangulation. Very 
 long lines have also been measured 
 (trigonometrically) by order of the 
 English Government, both at home 
 and in India, the mean result oi 
 which makes the earth's axis 7898 
 miles, 5 furlongs, 16 yards, and the 
 diameter of the Equator 7924 miles 
 7 furlongs. 
 
 Basement, the lower story or floor oi 
 a building; the story of a house 
 below the level of the ground. 
 Basements. As an alternative for 
 employing orders upon orders, the 
 ground-floor is made to assume the 
 appearance of a basement, and the 
 order that decorates the principal 
 story placed thereupon : in such 
 cases the basement should not be 
 higher than the order it supports, 
 nor lower than one-half the height 
 of the order ; but if a basement be 
 introduced merely for the purpose 
 
BAS 
 
 BASILICA. 
 
 BAS 
 
 of raising the principal or ground- 
 floor, it may be three, four, five, or 
 six feet high, at pleasure. 
 
 These basement stories are gene- 
 rally in rock-worked or plain rus- 
 tics ; and in no case should the 
 height of a rustic course be less 
 than one module of the order rest- 
 ing on the basement, nor should it 
 ever much exceed it : their joints, 
 if square, ought not to be broader 
 than one-eighth of the height of 
 the rustic, or narrower than one- 
 tenth, and their depth should equal 
 their breadth ; if chamfered, the 
 whole joint may be one-quarter to 
 one-third the height of the rustic, 
 the joint being always right-angled. 
 When the basement is high, it is 
 sometimes crowned with a cor- 
 nice, but a plat-band is more com- 
 monly used. Gvjilt. 
 Basenet, a helmet. 
 Base-plate'^ the foundation-plate of an 
 
 engine. 
 
 Basevi (George), an architect of con- 
 siderable taste, born in 1794, acci- 
 dentally killed in 1845. 
 Basil, to grind the edge of a tool to 
 
 an angle. 
 
 Basilica, in the time of the Romans, 
 a public hall or court of judicature. 
 After the conversion of the Em- 
 peror Constantine to Christianity, 
 these edifices were converted into 
 Christian churches. The Basilicce 
 of the Romans were the types from 
 which the early Christian places of 
 worship were taken ; and the ruins 
 of these buildings were the chief 
 materials used. In several instances 
 the columns that divide the centre 
 part of the church from the aisles 
 have been taken from other edifices, 
 either on account of the want of 
 artists capable of executing any- 
 thing equal to them, or the haste 
 with which they were erected. The 
 expedient that was adopted tends 
 to show that proportion was not 
 considered ; some columns were 
 reduced from their former height, 
 and others mounted on pedestals, 
 to suit the purposes to which they 
 
 41 
 
 were applied. Besides this total 
 disregard to proportion in the shafts 
 of the columns, capitals and bases 
 were applied without any consider- 
 ation to their fitness. The heathen 
 basilicae, generally situated in the 
 forums, were of rectangular form, 
 and divided into three or five parts 
 by rows of columns parallel to the 
 length of the building; another 
 colonnade at the extremity crossed 
 the former at right-angles, and in 
 the middle of the end wall was a 
 semicircular recess, in which was 
 situated the tribune of the judge. 
 These basilicae had likewise galle- 
 ries over the aisles, in which com- 
 mercial or other business was 
 transacted ; but in the Christian 
 churches this was appropriated to 
 the women, who (as in the Jewish 
 synagogues) were not allowed to 
 join with the men in the lower 
 parts of the building. These gal- 
 leries were omitted in the after 
 basilicae, and one of the aisles was 
 retained solely for their use. Six 
 of the principal churches or basi- 
 licae at Rome are attributed to the 
 zeal of Constantine. The basilicae 
 of St. John de Lateran, St. Peter, 
 St. Laurentius, St. Paul, St. Agnes, 
 and St. Stephen were built by him, 
 besides the baptisterium that bears 
 his name. 
 
 The Christian Basilica may be 
 sketched as follows : 
 
 1. The 4trium, or court of en- 
 trance, usually surrounded by a 
 columned portico as in the heathen 
 temples. This was an addition to the 
 heathen basilica. 
 
 2. The Portico, in front of the 
 building, called the Narthex or 
 Scourge reserved for the catechu- 
 mens and penitents, the former 
 being confined to its precincts till 
 baptism, the latter till ecclesiastical 
 absolution. 
 
 3. In the interior, the central 
 area, or nave, parted from its side- 
 aisles by rows of columns in the 
 smaller churches single.in the larger 
 double ; the rows next the nave 
 
BAS 
 
 BASINS. 
 
 HA! 
 
 almost invariably supported* round 
 arches instead of an unbroken archi- 
 trave, and upon these arches rested 
 the main walls of the building ; the 
 walls were pierced with windows, 
 under which often ran lines of 
 mosaic ; both nave and aisles were 
 crowned with a wooden roof, and 
 under that of the aisles Triforia, or 
 galleries, as in their pagan proto- 
 types, were sometimes provided for 
 the women. 
 
 4. The Cancellum, Chancel, or 
 Choii the upper part of the 
 nave, raised two or three steps, 
 railed off or separated by a low 
 wall, and appropriated to the sing- 
 ers and inferior clergy ; within it, 
 sometimes on the same side, more 
 frequently on the opposite, stood 
 the Ambones, or desks, that on the 
 left for reading the Gospel, that 
 on the right for the Epistle ; the 
 Paschal candlestick, emblematic of 
 revealed religion, being fixed adja- 
 cent to the former. The congre- 
 gation stood on either side the can- 
 cellum, the men to the right, the 
 women to the left, as in the heathen 
 basilicas. 
 
 5. The Triumphal Arch, intro- 
 ducing from the central nave into 
 the sanctuary, and thus figurative 
 of the transition through death 
 from the Church Militant on earth 
 to the Church Triumphant in 
 Heaven, respectively symbolized by 
 the nave and sanctuary : subjects 
 allusive to this triumph, the Sa- 
 viour in glory or the Vision of the 
 New Jerusalem of the Apocalypse, 
 were usually represented on it in 
 mosaic. 
 
 6. The Transept, Presbytery, or 
 Sanctuary, elevated by steps, in 
 the centre of which stood the altar, 
 originally uncovered, but after- 
 wards surmounted by a ciborium 
 or tabernacle supported by small 
 pillars. 
 
 7. The Tribune or Absis, within 
 which, overlooking the church, 
 arose the throne of the bishop, 
 flanked to the right and left by the 
 
 of his attendant clergy. Th 
 side-aisles were terminated b; 
 similar absides of smaller propor 
 tions. 
 
 8. Lastly, the Crypt, beneath th< 
 sanctuary, generally half-sunk be 
 low the level of the earth, an opei 
 screen or grating admitting a sigh 
 of its interior from the nave, and o 
 the Confession, the tomb or shrine 
 containing the relics of the sainl 
 or martyr. The theory of a primitive 
 church presumed it to be built ovei 
 a catacomb. S. Agnes, S. Lorenzo, 
 S. Martino, S. Prassede, and a few 
 others at Rome actually are so; 
 but as this could rarely be the 
 case elsewhere, artificial catacombs 
 or crypts were dug to represent 
 them. 
 
 At Rome, the Basilica of San 
 Lorenzo, situated about a mile from 
 the city on the Via Tiburtina. 
 
 The Basilica of Santl Croce in 
 Gierusalemme. 
 
 The Basilica of San Giovanni 
 in Laterano, the cathedral church 
 of Rome, called the metropolitan 
 church of the Christian world ; it is 
 also sometimes named the Basilica 
 Constantiniana. 
 
 The Basilica of San Sebastiano 
 fuori le mura. 
 
 The Basilica of Santa Maria 
 Maggiore, which is also sometimes 
 called the Basilica Laberiana. 
 
 The Basilica of Santa Maria in 
 Trastevere. 
 
 The remaining Basilica is either 
 that of San Pietro in Vaticano, or 
 of San Paolo fuori le mura ; indeed 
 both of them ought to be included 
 in the number, as they have respec- 
 tively the Porta Santa. 
 Basilicula, a shrine, oratory, or ceno- 
 taph. 
 
 Basins and ewers. In early times, 
 before the cleanly custom of using 
 a fork was practised, the hands 
 were frequently washed during 
 dinner : a basin and ewer were 
 handed for that purpose by an at- 
 tendant. At the feast given by 
 Henry VIII. to the French am". 
 
 42 
 
BAS 
 
 BATH. 
 
 BAT 
 
 bassadors, there were three ewry 
 boards ; one for the king, another 
 for the queen, and the third for the 
 princes, etc. 
 
 Basin, a concave piece of metal made 
 use of by opticians to grind their 
 convex glasses in. 
 
 Basin, a reservatory of water; a 
 canal ; a pond ; a dock for repair- 
 ing ships. 
 
 Basset. The basset or outcrop means 
 the emergence at the surface of the 
 different mineral strata from be- 
 neath each other. 
 
 Basset, or Outfall, applied to open- 
 ings from or into mines to the sur- 
 face. 
 
 Bas-relief, orBasso-rilievo, low or flat 
 relief, applied to sculpture con 
 nected more or less with a plane 
 surface, and of which the figures do 
 not project in their full proportions. 
 
 Bast, lime-tree bark made into ropes 
 and mats. 
 
 Bastard stucco, a three-coated plas- 
 ter, the first generally roughing in 
 or rendering; the second floating, 
 as in trowelled stucco ; but the 
 finishing coat contains a little hair 
 besides the sand : it is not hand- 
 floated, and the trowelling is done 
 with less labour than in what is 
 called trowelled stucco. 
 
 Bastard-toothed file, in smithing, that 
 employed after the rubber. 
 
 Bastard wheel, a flat bevel-wheel, or 
 one which is a near approach to a 
 spur-wheel. 
 
 Bastida, in the twelfth century, a 
 place of defence, a fortress. 
 
 Bastille, a prison; a castle, tower, 
 fortress., or any place of defence. 
 
 Bastion, a rampart, bulwark, or 
 earthen mound. 
 
 Batardeau, a coffer-dam, or case of 
 piling without a bottom, for build- 
 ing the piers of a bridge. 
 
 Batch, in mining, a certain quantity of 
 ore sent to the surface by any pair 
 of men. 
 
 Bateau, a light boat, long in propor- 
 tion to its breadth. 
 
 Bateman liyht, a window in which 
 the sides of the aperture are left to 
 
 43 
 
 admit light, an upright, and the 
 bottom horizontal. 
 Bath, a receptacle for water, in which 
 to plunge, wash, or bathe the body. 
 Among the Romans, baths were 
 erected magnificent both in style 
 and purpose, and many of them of 
 great architectural beauty. In later 
 times the bath was always used by 
 the Romans before they went to 
 their supper. The rich generally 
 had hot and cold baths in their 
 own houses ; and it was not till the 
 time of Augustus that the baths 
 assumed an air of grandeur and 
 magnificence. The situation chosen 
 for baths ought to be sheltered 
 from the north and north-east. 
 The caldaria and tepidaria should 
 be made to receive their light from 
 the west : or, should local circum- 
 stances not admit of this dispo- 
 sition, they may both be made to 
 face the south, because the general 
 time of bathing is from midday un- 
 til sunset. One thing necessary to 
 be observed is, that the caldaria of 
 that division of the bath which is 
 appropriated to the women should 
 be contiguous to that exclusively 
 used by the men, and have the 
 same aspect ; for then the cop- 
 pers of both may be heated from 
 the same furnace. Three brazen 
 vessels are fixed over the furnace, 
 which are severally called calda- 
 rium, tepidarium,and frigidarium : 
 they are so arranged, that whatever 
 heated water is taken from the 
 first, it is replaced by warm water 
 from the second, the deficiency of 
 which is supplied, in a similar man- 
 ner, from the third. The concave 
 coverings of the small tubes of both 
 baths are likewise heated from the 
 same furnace. The insulated stages 
 of the caldaria are thus constructed: 
 the floor is made inclining towards 
 the furnace, so that if a ball were 
 placed upon any part of it, it would 
 not remain at rest, but take a direc- 
 tion towards the mouth ; by which 
 means the flame will more easily 
 pervade the interval between the 
 
BAT 
 
 BATTERY. 
 
 BAY 
 
 floors, which is paved with tiles a 
 foot and a half square : upon the 
 floor, earthen props, eight inches 
 each way, are arranged at such in- 
 tervals as to receive upon them 
 square tiles two feet in length : the 
 props are two feet in height ; the 
 tiles which form them are cemented 
 with clay and hair mixed together. 
 The square tiles which they support 
 form the substratum of the pave- 
 ment of the caldaria. 
 Bath metal, a mixed metal, otherwise 
 
 called Prince's metal. 
 Bath-stone, Bath oolite ; minute glo- 
 bules, cemented together by yel- 
 lowish earthy calcareous matter ; it 
 is much used in building, but is not 
 a lasting material. It is soft when 
 quarried, but hardens by exposure 
 to the air. 
 
 Batifolium, a movable wooden tower 
 used by besiegers in attacking a 
 fortress. 
 
 Batten, in carpentry, a scantling of 
 wooden stuff, from two to four 
 inches broad, and about one thick, 
 principally used for wainscot, on 
 which also are bradded, on the plain 
 boards, also batten doors, those 
 which resemble wainscot-doors, but 
 are not so, for in wainscot-doors 
 the panels are grooved in the fram- 
 ing. 
 
 Eat fens (nautical), thin strips of wood 
 put around the hatches to keep the 
 tarpaulin down ; also put upon 
 rigging to keep it from chafing. 
 A large batten widened at the end, 
 and put upon rigging, is called a 
 Scotchman. 
 
 Batter, to displace a portion of the 
 iron of any bar or other piece by 
 the blow of a hammer, so as to 
 flatten or compress it inwardly, and 
 spread it outwardly on all sides 
 around the place of impact. 
 Batter, a term applied to walls built 
 out of the upright, or gently sloping 
 inwards ; wharf walls and retain- 
 ing walls built to support embank- 
 ments. 
 
 Batter, the leaning back of the up- 
 per part of the face of a wall, so as 
 
 to make the plumb-line fall within 
 the base. 
 
 Battery, in electricity, a combination 
 of coated surfaces of glass, com- 
 monly jars, so connected that they 
 may be charged at once and dis- 
 charged by means of a common 
 conductor. 
 
 Battlement, an open or interrupted 
 parapet on the roof of a building; 
 a parapet with embrasures. 
 
 Battory, a name given by the Hans 
 Towns to their country-houses 
 and warehouses in foreign coun- 
 tries. 
 
 Baugium, an outhouse or domestic 
 office. 
 
 Baulk, a piece of foreign fir or deal, 
 from 8 to 16 inches square, being 
 the trunk of a tree of that species 
 of wood ; generally brought to a 
 square for the use of building. 
 
 Bawdrick, a cord or thong for the 
 clapper of a bell ; a sword-belt ; a 
 jewel. 
 
 Bawk, a cross-beam in the roof of a 
 house which unites and supports 
 the rafters ; a tie-beam. 
 
 Bay, a division of a roof or vaulting 
 of a building, consisting of the 
 space between the beams or arches. 
 A part of a window between the 
 mullions is often called a bay or 
 day. 
 
 Bay, in plastering, the space between 
 the skreeds, prepared for regulating 
 and working the floating-rule. 
 
 Bay of joists, the joisting between 
 two binding joists, or between two 
 girders when binding joists are not 
 used. 
 
 Bay of roofing, the small rafters and 
 their supporting purlins between 
 two principal rafters. 
 
 Bay-salt, salt obtained by evaporating 
 sea-water in shallow ponds by the 
 heat of the sun ; it is of a dark grey 
 colour, and contains iodine. 
 
 Bay-tree, a native of Italy and Greece ; 
 it grows to the height of thirty 
 feet, and its wood is aromatic. 
 
 Bay-window, an oriel window; a win- 
 dow jutting outwards; frequently 
 called a bow-window. 
 
 44 
 
BAY 
 
 BEAMS. 
 
 Bayeux tapestry, ordered to be work- 
 ed by Matilda, the Queen of Wil- 
 liam the Conqueror. 
 
 Bazaar, a market-place. 
 
 Beacon, a post or buoy placed over a 
 shoal or bank, to warn vessels off: 
 also a signal-mark on land ; a tower 
 placed on an eminence, with a light 
 to warn against the approach of 
 danger. 
 
 Beaconc.ge, dues levied for the main- 
 
 x tenance of beacons. 
 
 Bead, a small globular ornament used 
 in ancient and modern architec- 
 ture. 
 
 Bead and Butt work, in carpentry, 
 framing in which the panels are 
 flush, having beads stuck or run 
 upon the two edges, the grain of the 
 wood being in the direction of them. 
 
 Bead and quirk, a bead stuck on the 
 edge of a piece of stuff, flush with 
 its surface. 
 
 Bead-butt and square-work, framing 
 with bead and butt on one side ; 
 and square on the other : used in 
 doors. 
 
 Bead-plane, a moulding plane of a 
 semi-cylindric contour, generally 
 used in sticking a moulding of the 
 same name on the edge or on the 
 side close to the arris. 
 
 Beak, the crooked end of a piece of 
 iron, to hold anything fast. 
 
 Beak, a small pendent fillet, forming 
 a channel behind, to prevent water 
 from running down the lower bed 
 of the cornice. 
 
 Beak-head, a small platform at the 
 fore-part of the upper deck in large 
 ships. 
 
 Beak-iron, the conic part of the an- 
 vil, with its base attached to the 
 side, and its axis horizontal. 
 
 Re aking -joint, the joint formed by the 
 meeting of several heading joints 
 in one continued line, which is 
 sometimes the case in folded floors. 
 
 Beam, a horizontal piece of iron or 
 timber, used to resist a force or 
 weight, as a tie-beam, where it acts 
 as a string, or chain, by its ten- 
 sion ; as a collar-beam, where it 
 acts by compression ; as a bres- 
 
 summer, where it resists a trans- 
 verse insisting weight. 
 Beam, in steam-engines, a large lever 
 turning upon a centre, and forming 
 the medium of communication be- 
 tween the piston-rod and the crank- 
 shaft. 
 
 Beam of an anchor, the straight part 
 or shank to which the hooks are 
 fastened. 
 
 Beams. FORMS OF BEAMS. In the 
 construction of beams, it is ne- 
 cessary that their form should be 
 such that they will be equally 
 strong throughout; or, in other 
 words, that they will offer an equal 
 resistance to fracture in all their 
 parts, and will, therefore, be equally 
 liable to break at one part of their 
 length as at another. 
 
 If a beam be fixed at one end 
 and loaded at the other, and the 
 breadth uniform throughout its 
 length, then, that the beam may be 
 equally strong throughout, its form 
 must be that of a parabola. 
 
 This form is generally used in 
 the beams of steam-engines; and 
 in double-acting steam-engines the 
 beam is strained sometimes from 
 one side, and sometimes from the 
 other ; therefore, both the sides 
 should be of the same form. 
 
 Mr. Emerson gives the load that 
 
 may be safely borne by a square 
 
 inch rod of each of the following : 
 
 Ibs. avoird. 
 
 Iron rod an inch square "I ^ A , nn 
 will bear . . . .} /b > 4 0< 
 
 Brass ...... 35,600 
 
 Hempen rope . . . 19,600 
 
 Ivory ...... 15,700 
 
 7,850 
 
 6,070 
 5,360 
 5,000 
 5,000 
 4,760 
 . 2Q() 
 
 430 
 914 
 
 prac- 
 
 elder, 
 
 Elm, ash, beech 
 Walnut, plum 
 Red fir, holly, 
 
 plane, crab . . . 
 Cherry, hazel . . . 
 Alder, asp, birch, wil- \ 
 low ...... J 
 
 Lead ...... 
 
 Freestone ..... 
 
 He also gives the following 
 
 45 
 
BEA 
 
 BEAMS. 
 
 BEA 
 
 tical rule, viz. That a cylinder, the 
 diameter of which is d inches, 
 loaded to one-fourth of its absolute 
 strength, will carry as follows : 
 
 cwt. 
 
 Iron 135 x d 2 
 
 Good rope ... 22 x d 2 
 
 Oak 14 x <P 
 
 Fir 9 x d 2 
 
 He also adds, that a cylindric rod 
 of good clean fir, of an inch cir- 
 cumference, drawn in length, will 
 bear at its extremity 400 Ibs. ; and 
 that a spar of fir, 2 inches diameter, 
 will bear about 7 tons, but not more. 
 A rod of good iron, of an inch 
 circumference, will bear nearly 3 
 tons weight. 
 
 A good hempen rope, of an inch 
 circumference, will bear 1000 Ibs. 
 being at its extremity. 
 
 Mr. Barlow gives the following 
 table as a mean derived from his 
 experiments on the strength of 
 direct cohesion on a square inch of 
 the following : 
 
 Ibs. 
 Box, about .... 20,000 
 
 Ash 17,000 
 
 Teak 15,000 
 
 Fir 12,000 
 
 Beech 11,500 
 
 Oak 10,000 
 
 Pear 9,800 
 
 Mahogany .... 8,000 
 
 TRANSVERSE STRENGTH OF 
 BEAMS, ETC. The transverse 
 strength of rectangular beams, or 
 the resistance which they offer to 
 fracture, is as the breadth and 
 square of the depth : therefore, if 
 two rectangular beams have the 
 same depth, their strengths are to 
 each other as their breadths ; but 
 if their breadths are the same, 
 then their strengths are to each 
 other as the squares of their depths. 
 
 The transverse strengths of 
 square beams are as the cubes of 
 the breadths or depths. Also, in 
 cylindrical beams, the transverse 
 strengths are as the cubes of the 
 diameters. 
 
 Thus, if a beam which is one foot 
 broad and one foot deep, support a 
 given weight, then a beam of the 
 same depth, and two feet broad, 
 will support double the weight. 
 
 But if a beam be one foot broad 
 and two feet deep, it will support 
 four times as much as a beam one 
 foot broad and one foot deep. 
 
 If a beam one foot square sup- 
 port a given weight, then a beam 
 two feet square will support eight 
 times as much. Also, a cylinder 
 of two inches in diameter will sup- 
 port eight times as much as a cy- 
 linder one inch in diameter. 
 
 The following table of data is 
 extracted from tables in Barlow's 
 
 Teak 2,462 
 
 English oak .... 1,672 
 
 Canadian do 1,766 
 
 Dantzic do 1,457 
 
 Adriatic do 1,383 
 
 Ash 2,026 
 
 Beech 1,556 
 
 Elm 1,013 
 
 Pitch pine 1,632 
 
 Red pine 1,341 
 
 New England fir . . . 1,102 
 
 Riga fir 1,108 
 
 Mar Forest fir. . . . 1,262 
 
 Larch 1,127 
 
 Beam-ends. A ship is said to be on 
 her beam-ends when she inclines 
 very much on one side, so that her 
 beams approach to a vertical posi- 
 tion. 
 
 Beam-engine, generally a land en- 
 gine, which has the top of the pis- 
 ton-rod connected to one end of a 
 lever or beam ; by a contrivance 
 called a parallel motion, the beam 
 vibrates upon a central axis, and 
 communicates the motion of the 
 piston to the crank by means of a 
 connecting-rod attached to the 
 other end of the beam, and also 
 gives motion to the various parts. 
 Beam filling, the brickwork, or ma- 
 sonry, brought up from the level 
 of the under to the upper sides of 
 beams. 
 Beam gudgeons, the bearings on the 
 
 46 
 
SEA 
 
 BEDS. 
 
 BED 
 
 centre of the beam, or the central 
 pivot upon which it vibrates. 
 
 Beam of a balance, the horizontal 
 piece of iron from the ends of 
 which the scales are suspended. 
 
 Beams, in naval architecture, strong 
 thick pieces of timber stretching 
 across the ship from side to side, to 
 support the decks : they are sus- 
 tained at each end by thick planks 
 in the ship's side, called clamps, 
 upon which they rest. 
 
 Bearer, anything used by way of sup- 
 port to another weight. 
 
 Bearer, in turning, that part of the 
 lathe which supports the puppets. 
 
 Bearing, the distance that a beam 
 or rafter is suspended in the clear : 
 thus, if a piece of timber rests upon 
 two opposite walls, the span of the 
 void is called the bearing, and not 
 the whole length of the timber. 
 
 Bearing, that part of a shaft or 
 spindle which is in contact with 
 the supports. 
 
 Hearing, a word used in describing 
 a plaster figure copied from the 
 antique. It is generally said, if 
 the drawing or outline of a figure 
 has not the same bearings or angles 
 of inclination as the original pos- 
 esses, that it is out in all its 
 bearings. 
 
 Bearing, in heraldry, the figures on 
 a coat of arms ; a coat of arms in 
 general. 
 
 Bearing, the direction of an object 
 from the person looking. In ship- 
 ping,the bearings of a vessel are the 
 widest part of her below the plank- 
 sheer ; that part of her hull which 
 is on the water-line when she is at 
 anchor and in her proper trim. 
 
 Beat away, in mining, to excavate ; 
 usually applied to hard ground. 
 
 Beating, in navigation, the operation 
 of making progress at sea against 
 the wind. 
 
 [Beaufet, a cupboard or niche. 
 
 Beaufrey, a beam or joist. 
 
 Beau ideal, in painting, that beauty 
 which is freed from the deformity 
 and the peculiarity found in nature 
 in all individuals of a species. 
 
 Beauty, in architecture, consists of 
 the following qualities : magnitude 
 and strength, order and harmony, 
 richness and simplicity ; Construc- 
 tion, in which the chief requisites 
 are magnitude and strength, order 
 and harmony ; Decoration, whose 
 requisites are richness or simplicity, 
 according to the nature of the com- 
 position. 
 
 Beazley (Saml.), an architect of re- 
 putation, particularly in the con- 
 struction of theatres ; he also 
 executed with success many other 
 buildings. Born 1786 ; died in 
 1851. 
 
 Becalm, to intercept the wind by al- 
 ternate tacks. 
 
 Beck, a little river or brook. 
 
 BecJc, an English weight containing 
 sixteen English pounds, or two 
 gallons. 
 
 Becket, a piece of rope, placed so as 
 to confine a spar or another rope ; 
 a handle made of rope in the form 
 of a circle. 
 
 Bed of a brick, the horizontal sur- 
 faces as disposed in a wall. 
 
 Bed, a term used in masonry to de- 
 scribe the direction in which the 
 natural strata in stones lie ; it is 
 also applied to the top and bottom 
 surface of stones when worked for 
 building. 
 
 Bed, in mining, a seam or horizontal 
 vein of ore. 
 
 Beds, of stonework, are the parallel 
 surfaces which intersect the face 
 of the work in lines parallel to the 
 horizon. 
 
 Beds and Bedding. Feather - beds, 
 bolsters, and pillows, filled with 
 feathers and down, with mattresses 
 and every other comfort of this 
 kind, seem to have been as well 
 known to, and enjoyed by, the su- 
 perior orders of society three cen- 
 turies ago, as they are now. Di- 
 rections are, however, mentioned 
 as having been given in the reign 
 of Henry VIII. " to examine every 
 night the straw of the king's bed, 
 that no daggers might be con- 
 cealed." 
 
 47 
 
BED 
 
 BEECHWOOD. 
 
 BEF 
 
 Beds (Trussing) were beds which 
 packed into chests, for travelling ; 
 and, considering the frequent re- 
 movals, these must have been the 
 most convenient kind. John of 
 Ghent seems to have always slept 
 in such beds, as by his will it ap- 
 pears that he demised to his wife 
 all the beds made for his body, 
 " called in England trussing-beds ;" 
 and the " best chambers " of both 
 Master Fermor and Sir Adrian Fos- 
 kewe had trussing-beds. 
 
 Bed-chambers: in Tudor times the 
 furniture of these apartments, in 
 great houses, was of the same gor- 
 geous character as that in the chief 
 rooms; and the paraphernalia of an 
 ancient dressing-table yielded only 
 in the splendour and costliness of 
 plate, to the cupboard of the great 
 chamber, or the altar of the chapel. 
 Like the hall, the state bed-cham- 
 ber had a high place, on which 
 were placed the 'standing bed' and 
 the 'truckle-bed :' on the former lay 
 the lord, and on the latter his at- 
 tendant. 
 
 Beddern, a refectory. 
 
 Bedding -stone, used in bricklaying, a 
 straight piece of marble : its use is 
 to try the rubbed side of the brick; 
 first, to square, to prove whether 
 the surface of the brick be straight ; 
 secondly, to fit it upon the leading 
 skewback, or leading end of the 
 arch. 
 
 Bed-mouldings. This may be under- 
 stood as a collective term for all 
 the mouldings beneath the corona 
 or principal projecting member of 
 a cornice, which, without bed- 
 mouldings, would appear too much 
 like a mere shelf. 
 
 Bed-plate, the foundation-plate of a 
 marine or a direct-action engine. 
 
 Bedsteads ; in Tudor times the posts, 
 head-boards, and canopies or sper- 
 vers of bedsteads were curiously 
 wrought and carved in oak, walnut, 
 box, and other woods, and variously 
 painted and gilt. Ginger-colour, 
 hatched with gold, was a favou- 
 rite style, but purple and crimson 
 
 were also used in their decoration. 
 
 Bede, among miners, a kind of pick- 
 axe used for separating the ores 
 from the rocks in which they lie. 
 
 Bedesmen, almsmen who prayed for 
 their benefactors and founders. 
 
 Bede-house, an almshouse or hospi- 
 tal. 
 
 Beech, a species of timber very much 
 used by artificers : while young, it 
 possesses great toughness, and is 
 of a white colour: the cohesive 
 strength of this timber requires 
 12,225 Ibs. weight to tear asunder 
 a piece one square inch in thick- 
 ness. 
 
 Beech-wood, common in Buckingham- 
 shire and Sussex as the best ; about 
 fifty feet high and thirty inches in 
 diameter; white, brown, and black 
 colour : it is used for piles in wet 
 foundations ; is used also, for its 
 uniform texture and closeness, in 
 in-door works, as the frames of 
 machines, bedsteads, and furniture ; 
 also for planes, tools, lathe-chucks, 
 keys, cogs of machinery, brushes, 
 handles, etc. 
 
 Beef-wood, red-coloured wood, gene- 
 rally applied to Botany Bay oak. 
 
 Beer-drawing machines are contriv- 
 ances by means of which beer is 
 drawn from a barrel or cask. 
 
 Beer or Bere stone, composed chiefly 
 of carbonate of lime, friable and 
 with partial indurations. It is ex- 
 tensively quarried at Bere, or Beer, 
 in Devon. 
 
 Bees, pieces of plank bolted to the 
 outer end of the bowsprit, to score 
 the fore-topmast stays through. 
 
 Beetle, or Maul, a large mallet to 
 knock the corners of framed work, 
 and to set it in its proper position : 
 the handle is about three feet in 
 length. 
 
 Beetle, or Boytle, a wooden instru- 
 ment or hammer for driving piles, 
 stakes, wedges, etc. 
 
 Before the beam, in naval architec- 
 ture, is an arc of the horizon com- 
 prehended between a line which 
 crosses a ship's length at right an- 
 gles, and some object at a distance 
 
 48 
 
BEH 
 
 BELL. 
 
 BEX 
 
 before it ; or between the line of 
 the beam, and that point of the 
 compass which she stems. 
 
 Behr (Geo. Hen.), published in 1732 
 a work on Strasburg Cathedral. 
 
 Belace, Belage, or to Belay, to fasten 
 any running rope when it is haled, 
 that it cannot run forth again ; to 
 mend a rope by laying one end over 
 another. 
 
 Belandre, in navigation, a sort of Nor- 
 man vessel. 
 
 Belay, to make a rope fast by turns 
 round a pin or coil, without hitch- 
 ing or seizing it. 
 
 Belfry, that part of the tower of a 
 church which contains bells. 
 
 Bell (Henry), late of Glasgow, who, 
 in 1812, tried Symington's plan for 
 navigating by propulsion a steam- 
 vessel on the Clyde. The vessel 
 ('The Comet') was 25 tons bur- 
 den, 40 feet long and 10 feet beam, 
 with a steam-engine of four-horse 
 power, which succeeded. 
 
 Bell, a metallic instrument rung in the 
 belfry of a church for the attend- 
 ance of divine worship, and upon 
 occasions of rejoicing ; composed 
 of three parts of copper and one of 
 tin, called bell-metal. 
 
 Bell : the body of a Corinthian or 
 Composite capital, supposing the 
 foliage stripped off, is called the 
 bell; the same is applied also to 
 the early English and other capitals 
 in Gothic architecture which in 
 any degree partake of this form. 
 
 Bell-cage, a timber frame, also called 
 Belfry, carrying one or more large 
 bells. 
 
 Bell-canopy, a canopy containing a 
 bell in harness. 
 
 Bell-chamber, the room containing 
 one or more large bells in harness. 
 
 Bell-cot, a structure presenting the 
 appearance of a steeple. 
 
 Bell-crank, a bent lever, used for 
 changing a vertical into a horizon- 
 tal motion. 
 
 Bell-gable, a term applied to the gable 
 of a religious edifice, having a plain 
 or ornamental niche for the recep- 
 tion of one or more bells. 
 
 Bell-trap, a contrivance, usually air- 
 tight, consisting of an inverted cup, 
 the edges of which dip into a 
 trench, gutter, or canal holding 
 water, and formed at the top of 
 a pipe, for the purpose of prevent- 
 ing foul smells ascending from the 
 drain into the air. 
 
 Bellows, the instrument for blowing 
 a fire, with an internal cavity so 
 contrived as to be of greater or less 
 capacity by reciprocating motion, 
 and to draw in air at one place while 
 the capacity is upon the increase, 
 and discharge it by another while 
 upon the decrease. The bellows are 
 placed behind the forge with a 
 pipe, and are worked by means of 
 a lever, called a rocket. Ster.m 
 machinery is now much used lor 
 blowing furnaces. 
 
 Belloius, or water blowing-engine, is a, 
 machine in which the stream of air 
 is supplied by the flowing of water. 
 
 Belly, the hollow part of a compass 
 timber, the round part of which is 
 called the back. 
 
 Belt, in building, a string-course and 
 blocking-course ; a course of stones 
 projecting from a wall, either 
 moulded, plain, fluted, or enriched. 
 
 Belvedere, a turret, lantern, or cupola, 
 raised above the roof of a building. 
 It is sometimes applied in Italy to 
 open galleries or corridors. 
 
 Belzoni (G.), an explorer of Egyptian 
 antiquities; died in 1823. 
 
 Bema, an ambo, or reading-desk ; a 
 raised structure for the seat or 
 throne of a bishop. 
 
 Bema, the sanctuary, presbytery, or 
 chancel of a church. 
 
 Bema, in Greek, the platform from 
 which the orators spoke in the 
 Athenaeum. 
 
 Bema, a bishop's throne. 
 
 Ben-alive, a Cornish term in mining. 
 
 Bench, for cai-penters and joiners to 
 do their work on, usually 10 or 12 
 feet in length, and about 2^ feet in 
 width. 
 
 Bench-mark, in surveying, is applied 
 to a mark showing the starting- 
 
 , point in levelling along a line, and 
 
BEN 
 
 BEVEL. 
 
 BEY 
 
 to similar marks affixed at conve- 
 nient distances to substantiaUor 
 permanent objects, to show the ex- 
 act points upon which the levelling 
 staffs were placed when the various 
 levels were read, thus facilitating 
 reference and correction. 
 
 Bench-planes. The jack-plane, the 
 trying-plane, the long-plane, the 
 jointer, and the smoothing-plane, 
 are called bench-planes. 
 
 Bench-table, a low stone seat round 
 the interior of the walls of many 
 churches. 
 
 Bend, in mining, indurated clay; a 
 name given by miners to any indu- 
 rated argillaceous substance. 
 
 Bend, the form of the ship from the 
 keel to the top of the side, as the 
 midship bend, etc. 
 
 Bends, the strongest parts of a ves- 
 sel's side, to which the beams, 
 knees, and futtocks are bolted. 
 
 Bending-strakes, two st rakes wrought 
 near the coverings of the deck, 
 worked all fore and aft, about one 
 inch or one inch and a half thicker 
 than the rest of the deck, and let 
 down between the beams and ledges 
 so that the upper side is even with 
 the rest. 
 
 Bending of timber. The process of 
 bending wood to any required curve 
 depends on the property of heat, as 
 i . < pressure increases the elasticity 
 of the wood. 
 
 Benefice, a church endowed with a 
 revenue for the performance of 
 divine service. 
 
 Benefier, a vessel to contain holy 
 water ; a font, or piscina. 
 
 Ben-heyl, in Cornish mining, rich in 
 tin. 
 
 Ken tick-shrouds, formerly used, and 
 extending from the futtock-staves 
 to the opposite channels of a vessel. 
 
 Benzine, the bicarburet of hydrogen, 
 procured by heating benzoic acid 
 with lime. 
 
 Bergamo, a coarse tapestry. 
 
 Bergmote, a court held on a hill, for 
 the decision of controversies among 
 miners. 
 
 Berne machine, for rooting up trees ; 
 
 50 
 
 the invention of Peter Sommcr, of 
 Berne. 
 
 Berth, the place where a vessel lies ; 
 the place in which a man sleeps. 
 
 Berth, convenient sea-room to moor 
 a ship. 
 
 Bertying a ship, the rising up of the 
 ship's sides. 
 
 Beryl, a pellucid gum, of a bluish- 
 green colour, found in the East 
 Indies, Peru, etc.; used by artists. 
 
 BetheVs patent for preserving wood. 
 This patent was taken out in 
 1838, and consists in thoroughly 
 impregnating the wood with oil of 
 tar containing creosote and a crude 
 solution of acetate of iron. 
 
 7>V//y, in mechanics, an instrument to 
 break open doors. 
 
 Bet on, the French name for concrete : 
 bet on is composed by first mixing 
 the proper proportions of lime and 
 sand, either by hand or by a pug- 
 mill, in the same manner as for 
 ordinary mortar. 
 
 Bevel, any angle except one of 90 de- 
 grees. " 
 
 Bevel, in bricklaying, is for drawing 
 the soffit-line on the face of the 
 bricks. 
 
 Bevel, in joinery : one side is said to 
 be bevelled with respect to another, 
 when the angle formed by these 
 two sides is greater or less than a 
 right angle. 
 
 Bevel gear, in mechanics, denotes a 
 species of wheel-work where the 
 axis or shaft of the leader or driver 
 forms an angle withthe axis or shaft 
 of the follower or the driven. In 
 practice it is requisite to have finite 
 and sensible teeth in bevel gear : 
 these are made similarly to those of 
 spur gear, except that in the latter 
 they are parallel, while in bevel gear 
 they diminish in length and thick- 
 ness in approaching the apex of the 
 cone : the teeth are of any breadth, 
 according to the strength required. 
 Bevel gearing is stronger, works 
 smoother, and has superseded the 
 face-wheel and trundle. 
 
 Bevelling, in ship-building, the wind- 
 ing of a timber, etc., agreeably to 
 
BEV 
 
 BIMEDIAL LINE. 
 
 BIR 
 
 directions given from the mould- 
 loft. 
 
 Bevel-wheel, a wheel having teeth 
 formed so as to work at an angle 
 either greater or less than half a 
 right angle. 
 
 Bibbs, in ship-building, pieces of tim- 
 ber bolted to the hounds of a mast, 
 to support the trestle-trees. 
 
 B'lhlvttheca, in Greek, the place, apart- 
 ment, or building where books 
 were kept. 
 
 Bicarbide of hydrogen. This gas is 
 known by the names of light car- 
 buretted hydrogen, marsh-gas, fire- 
 damp, and gas of the acetates. It 
 is discharged from fissures in coal 
 in large quantities, and from the 
 bottoms of the pools in which there 
 is vegetable matter. 
 
 Bice, a blue colour used in painting, 
 prepared from the Lapis Armenius. 
 
 Bice, or Bise, in painting, a pale blue 
 colour, procured by the reduction 
 of salt to a fine powder. 
 
 Bicellum, the dwelling of a tradesman, 
 having under it two vaults, for the 
 reception of merchandise. 
 
 Bichoca, a turret or watch-tower. 
 
 Bier-balk, the church-road for burials. 
 
 Bifrons, in sculpture, double-fronted 
 or faced, usually applied to Janus. 
 
 Biyelf, an arch or chamber. 
 
 Bigg, to build. 
 
 Bigger, a builder. 
 
 Bight, the double part of a rope when 
 it is folded, in contradistinction 
 from the ends. 
 
 i Bilander, a small vessel with two 
 masts, used chiefly in the canals of 
 the Low Countries. 
 
 Bilboes, large bars or bolts of iron, 
 with shackles sliding on them, used 
 for criminals. 
 
 Bilage, the breadth of a floor of a 
 ship when she lies aground. 
 
 Bilge-pump, that which is applied to 
 the side of a ship, to exhaust or 
 pump out the bilge-water. 
 
 Bilection-mouldings, those surround- 
 ing the panels, and projecting 
 before the face of a door, gate, 
 etc. 
 
 Bilge, that part of the floor of a ship 
 
 which approaches nearer to a hori- 
 zontal than to a perpendicular di- 
 rection. 
 
 Bilge-pump, the forcing-pump worked 
 by a marine engine, to discharge 
 the bilge-water from the vessel. 
 
 Bilge-pump rod, the plunger-rod, or 
 rod connecting the piston of the 
 bilge-pump to one of the side- 
 levers. 
 
 Bill, the point at the extremity of the 
 fluke of an anchor. 
 
 Billet-moulding, an ornament used in 
 string-courses and the archivolts of 
 windows and doors. 
 
 Billiard-room. The apartment pre- 
 pared for the reception of a billiard 
 table, and therefore requiring to be 
 of specific dimensions. 
 
 Billion, in numbers, the sum of a mil- 
 lion of millions. 
 
 Bills, the ends of compass or knee- 
 timber. 
 
 Bimedial line, in geometry, the sum 
 of two medials. When medial lines, 
 equal only in power and containing 
 a rational rectangle, are compound- 
 ed, the whole will be irrational 
 with respect to either of the two ; 
 this is called a first birnedial line ; 
 but if two medial lines, commen- 
 surable only in power, and con- 
 taining a medial rectangle, be com- 
 pounded, the whole will be irra- 
 tional, and is then called a second 
 bimedial line. 
 
 Binary, in arithmetic, double. 
 
 Binder, one who undertakes to keep 
 a mine open. 
 
 Binding -joints, those beams in a floor 
 which support transversely the 
 bridgings above and the ceiling- 
 joists below. 
 
 Bindings, the iron wrought round the 
 dead-eyes. 
 
 Binnacle, a box near the helm, con- 
 taining the compass. 
 
 Binocular telescope, one to which both 
 eyes may be applied. 
 
 Bins, for wine, open subdivisions in a 
 cellar for the reception of bottles. 
 
 Birch-wood, a forest tree, common to 
 Europe and North America; an 
 excellent wood for turning, being 
 
 51 D 2 
 
BIU 
 
 BITUMEN. 
 
 BLA 
 
 of light colour, compact, and easily 
 worked. 
 
 Bird (Edward), painter, born at Wol- 
 verhampton, April 1772, died No- 
 vember 1819. 
 
 Bird's-eye perspective is of two kinds, 
 angular and parallel : it is used in 
 the drawings of extensive buildings 
 having spacious courts and gardens, 
 as palaces, colleges, asylums, etc. 
 The observer is supposed to be on 
 an eminence, and looking down on 
 the building, as from a steeple or 
 mountain. 
 
 Bird's -mouth, in carpentry, an interior 
 angle or notch cut in the end of a 
 piece of timber for its reception on 
 the edge of a pole or plate. It sig- 
 nifies also the internal angle of a 
 polygon. 
 
 Bireme, a vessel with two banks or 
 tiers of oars. 
 
 Birhomboidctl, having a surface of 
 twelve rhombic faces, which, being 
 taken six and six, and prolonged 
 till they intercept each other, would 
 form two different rhombs. 
 
 Birthing, ilie, working a top side, bulk- 
 heads, etc. 
 
 Bisection, in geometry, the division of 
 any quantity into two equal parts. 
 
 Bishops, prelates holding baronies of 
 the King or of the Pope, and exer- 
 cising ecclesiastical jurisdiction over 
 a certain extent of territory, called 
 their diocese. 
 
 Bismuth. This metal is found native, 
 crystallized in cakes, which gene- 
 rally contain small quantities of 
 silver; it is also combined with 
 oxygen, arsenic, and sulphur. 
 
 Bispia, abishopric or episcopal palace. 
 
 Bissextile, or leap-year, a year con- 
 sisting of 366 days, happening once 
 every four years, by the addition of 
 a day in the month of February, to 
 recover the six hours which the 
 sun spends in his course each year, 
 beyond the 365 days usually allow- 
 ed for it. 
 
 Bistre, a brown pigment, extracted 
 by watery solution from the soot 
 of wood fires, when it retains a 
 strong pyroligneous scent. It is 
 
 52 
 
 of a wax-like texture, and of a ci- 
 trine-brown colour, perfectly dura- 
 ble. It has been much used as a 
 water-colour, particularly by the 
 old masters, in tinting drawings 
 and shading sketches, previously to 
 Indian ink coming into general use 
 for such purposes. In oil, it dries 
 with the greatest difficulty. 
 
 Bisturres, small towers placed at in- 
 tervals in the walls of a fortress, 
 forming a barbican. 
 
 Bit, an instrument for boring holes in 
 wood, etc. 
 
 Bitter (a sea term), a turn of a cable 
 about the timbers called bitts, when 
 the ship lies at anchor. When a 
 ship is stopped by the cable, she is 
 said to be brought up by a bitter. 
 
 Bitternut-wood, a native of America, 
 is a large timber wood, measuring 
 30 inches when squared ; plain and 
 soft in the grain, like walnut. 
 
 Bitts, in ship-building, perpendicular 
 pieces of timber going through the 
 deck, placed to secure anything to. 
 The cables are fastened to them, if 
 there is no windlass. There are 
 also bitts to secure the windlass, 
 and each side of the heel of the 
 bowsprit. 
 
 Bitumen, a name for a number of 
 inflammable mineral substances, 
 known under the names of naph- 
 tha, mineral tar, mineral pitch, 
 sea- wax, asphalte, elastic bitumen, 
 or mineral caoutchouc, jet, mineral 
 coal, etc. 
 
 Bituminous cement, a factitious sub- 
 stance, used for pavements, for 
 roofs, and other useful purposes. 
 
 Bituminous limestone, a limestone of 
 a lamellar structure. 
 
 Black, the last and the lowest in the 
 series or scale of descending co- 
 lours ; the opposite extreme from 
 white ; the maximum of colour. 
 To be perfect, it must be neutral 
 with respect to colours individually, 
 and absolutely transparent, or desti- 
 tute of reflective power in regard 
 to light, its use in painting being 
 to represent shade or depth, of 
 which it is the element in a picture 
 
BLA 
 
 BLAST. 
 
 BLA 
 
 and in colours, as white is of light. 
 
 Black-band iron-stone, discovered by 
 Mr. David Mushet, in 1801, while 
 engaged in the erection of the 
 Calder Iron-works. Great prejudice 
 was excited against him by the 
 iron-masters, in presuming to class 
 the wild coals of the country with 
 iron-stones fit and proper for the 
 blast furnace ; yet that discovery 
 has elevated Scotland to a consi- 
 derable rank amongst the iron- 
 making nations of Europe, and pro- 
 duces an annual average income of 
 16,500 to Sir W. Alexander, Bart. 
 
 Black Botany Bay wood is the hardest 
 and most wasteful of all woods ; 
 some of the finest, however, if well 
 selected, exceeds all woods for ec- 
 centric turning. 
 
 Black chalk is an indurated black 
 clay, of the texture of white chalk : 
 its principal use is for cutting into 
 the crayons which are employed in 
 sketching and drawing. 
 
 Black dye : the ingredients of black 
 dye are logwood, Aleppo galls, ver- 
 digris, and sulphate of iron, or green 
 vitriol. 
 
 Black iron, malleable iron, in contra- 
 distinction to that which is tinned, 
 called white iron. 
 
 Black Jack, in mining, blende. 
 
 Black lead, plumbago, or graphite, is 
 a native carburet of iron, or oxide 
 of carbon, found principally at Bor- 
 rodale in Cumberland; consumed 
 in large quantities in the formation 
 of crayons and black-lead pencils 
 for writing, sketching, designing, 
 and drawing. 
 
 Black marble. The marble called in 
 commerce Nero Antico, and Egyp- 
 tian black, is the most beautiful 
 black marble without any ad- 
 mixture of other colours. In Eng- 
 land the chief quarries of uniform 
 colours and texture are at Ashford, 
 Bake well, Derby, etc. 
 
 Black ochre, a variety of the mine- 
 ral black, combined with iron and 
 alluvial clay. 
 
 Black tin, tin ore when dressed, stamp- 
 ed, and washed, ready for melting. 
 
 53 
 
 Black wadd, one of the ores of man- 
 ganese, used as a drying ingredient 
 in paints. 
 
 Blade, in joinery, is expressive of any 
 part of a tool that is broad and 
 thin, as the blade of an axe, of an 
 adze, of a chisel, of a square : the 
 blade of a saw is more frequently 
 called the plate. 
 
 Blades, the principal rafters or breaks 
 of a roof. 
 
 Blanc d' argent, or silver- white. This 
 is a false appellation for a white 
 lead, called also French white. It 
 is first produced in the form of 
 drops, is exquisitely white, but is 
 of less body then flake white, and 
 has all the properties of the best 
 white leads ; but, being liable to 
 the same changes, is unfit for gene- 
 ral use as a water-colour, though 
 good in oil or varnish. 
 
 Blake (William), a poor but meritori- 
 ous artist, was born in London, in 
 November 1757. The Canterbury 
 Pilgrimage was designed by him. 
 His first work was, however, the 
 Songs of Innocence ; his next, the 
 Gates of Paradise. Poverty-stricken 
 as he was, his cheerfulness never 
 forsook him ; he uttered no com- 
 plaint, he contracted no debt, and 
 continued to the last manly and in- 
 dependent. 
 
 Blast, the air introduced into a fur- 
 nace. 
 
 Blasting of stone, from rocks and 
 beds of stone, for the purpose of 
 quarrying and shaping stones to be 
 used for building purposes : the 
 ordinary implements used are the 
 jumper or cutting-tool, the ham- 
 mer, and scraper. For the process 
 and its effect, see Sir John Bur- 
 goyne's Rudimentary Volume on 
 Blasting, etc. 
 
 Blast-pipe, the waste steam-pipe of 
 an engine, but more particularly 
 applied to locomotive engines : in 
 the latter it leads from the exhaust 
 passages of the cylinders into the 
 chimney, and is of great use for 
 forming the draught through the 
 fire-tubes, as each jet of steam 
 
BLE 
 
 BLENDING. 
 
 BLO 
 
 emitted creates a partial vacuum in 
 the chimney, which is immediately 
 filled hy a current of air rushing 
 through the fire-grate. 
 
 Bleaching, an art divided into branches, 
 bleaching of vegetable and animal 
 substances requiring different pro- 
 cesses for whitening them. 
 
 Blend, a mineral substance resem- 
 bling lead. 
 
 Blende, in mining, an ore of zinc, 
 composed of iron, zinc, sulphur, si- 
 lex, and water : on being scratched, 
 it emits a phosphoric light. 
 
 Blending and melting, in colouring or 
 painting, are synonymous terms. 
 They imply the method of laying 
 different tints on buildings, trees, 
 etc., so that they may mingle to- 
 gether while wet, and render it 
 impossible to discover where one 
 colour begins and another ends. 
 A variety of tints of nearly the 
 same tone, employed on the same 
 object and on the same part, gives 
 a richness and mellowness to the 
 effect ; while the outline, insensibly 
 melting into the background, and 
 artfully disappearing, binds the ob- 
 jects together, and preserves them 
 in unison. 
 
 Bleostaning, mosaic pavement. 
 
 Block, a lump of wood or stone. 
 
 Blocks, pieces of wood in which the 
 sheaves or pulleys run, and through 
 which the ropes pass. 
 
 Block cornices and entablatures are 
 frequently used to finish plain build- 
 ings, where none of the regular or- 
 ders have been employed. Of this 
 kind there is a very beautiful one 
 composed byVignola, much used in 
 Italy, and employed by Sir Christo- 
 pher Wren to finish the second 
 design of St. Paul's cathedral. 
 
 Block-house, a building erected by be- 
 siegers for the investment of a cas- 
 tle. Block-houses were erected in 
 the time of Henry VIII. on the 
 south and south-western coast of 
 England. 
 
 Blocking-course, a course of masonry 
 or brick-work, laid on the top of a 
 cornice crowning a wall. 
 
 54 
 
 Blockings, small pieces of wood, fitted 
 in, or glued, or fixed to the interior 
 angle of two boards or other pieces, 
 in order to give strength to the joint. 
 
 Block -machinery, the machinery for 
 manufacturing ships' blocks, in- 
 vented by the elder Brunei, and 
 adjusted by the late Dr. Gregory. 
 
 Block-tin, tin cast into blocks or in- 
 gots. 
 
 Blondel (F.), architect, was born at 
 Ribemont, in Picardy, in 1617. 
 Principally employed in the con- 
 struction of fortresses, and pub- 
 lished several scientific works. 
 
 Blondel (J. P.), architect, son of the 
 preceding, born in Paris, 1705. 
 He published several very beautiful 
 works. 
 
 Blondel (J. F.), architecte du Roi, 
 was born at Rouen, in 1683, and 
 stated to be a brother of Frat^ois. 
 He was extensively employed as 
 an architect and decorator by the 
 Court, and published many beauti- 
 ful works. 
 
 Blondel (J. B.), architect to the city 
 of Paris. Last of the family. He 
 constructed the Temple, Marche 
 St. Germain, etc. 
 
 Blood-red heat, the degree of heat 
 which is only necessary to reduce 
 the protuberances on coarse iron 
 by the hammer, in order to prepare 
 it for the file, the iron being pre- 
 viously brought to its shape. This 
 heat is also used in punching small 
 pieces of iron. 
 
 Bloom, a mass of iron after having un- 
 dergone the first hammering. 
 
 Bloom (a), in iron- works, is in form 
 a square piece 2 feet long. 
 
 Blower, in mining, a smelter. 
 
 Blowing, the projection of air into a 
 furnace, in a strong and rapid cur- 
 rent, for the purpose of increasing 
 combustion. 
 
 Blow-off cock, the stop-cock in the 
 blow-off pipe. 
 
 Blow-off pipe, the pipe fixed to the 
 bottom of a boiler, for discharging 
 the sediment, which is effected by 
 blowing through a portion of the 
 water from the boiler. 
 
BLO 
 
 BLOW-PIPE. 
 
 BLO 
 
 Blow-pipe. The blow-pipe is a most 
 valuable little instrument to the 
 mineralogist, as its effects are strik- 
 ing, rapid, well characterized, and 
 pass immediately under the eye of 
 the operator. The most efficacious 
 flame is produced by a regular, mo- 
 derate stream of air ; while the act 
 of blowing with more force only 
 has the effect of fatiguing the mus- 
 cles of the cheeks, oppressing the 
 chest, and at the same time renders 
 the flame unsteady. 
 
 The student should fill his mouth 
 with air, so as to innate the cheeks 
 moderately,and continue to breathe 
 without letting the air in the mouth 
 escape ; the blow-pipe may then be 
 introduced between the lips, and 
 while the breathing is carried on 
 through the medium of the nose, 
 the cheeks will expel a stream of 
 air through the blow-pipe ; and by 
 replenishing the mouth at each ex- 
 piration, and merely discharging 
 the surplus air through the nostrils, 
 a facility will be acquired of keep- 
 ing up a constant stream of air. 
 
 The best flame for the purpose 
 of this instrument is that of a thick 
 wax candle, such as are made for 
 the lamps of carriages, the wick 
 being snuffed to such a length as 
 to occasion a strong combustion : 
 it should be deflected a little to one 
 side, and the current of air directed 
 along its surface towards the point : 
 a well-defined cone will be pro- 
 duced, consisting of an external 
 yellow, and an internal blue flame. 
 At the point of the former, calcina- 
 tion, the oxidation of metals, roast- 
 ing of ores to expel the sulphur 
 and other volatile ingredients, may 
 be accomplished ; and by the ex- 
 treme point of the latter (which 
 affords the most intense heat) fu- 
 sion, the deoxidation of metals, and 
 all those operations which require 
 the highest temperature, will be 
 effected. The piece of mineral to 
 be examined must necessarily be 
 supported on some substance ; and 
 for the earths, or any subject not 
 
 being metallic, or requiring the 
 operation of a flux, a spoon or pair 
 of forceps made of platina will be 
 found useful ; but, as the metals 
 and most of the fluxes act on pla- 
 tina, the most serviceable support, 
 for general purposes, will be a piece 
 of sound, well-burnt charcoal, with 
 the bark scraped off, as free as pos- 
 sible from knots or cracks : the 
 piece of mineral to be examined 
 should not in general be larger than 
 a pepper-corn, which should be 
 placed in a hollow made in the 
 charcoal ; and the first impression 
 of the heat should be very gentle, 
 as the sudden application of a high 
 temperature is extremely liable to 
 destroy those effects which it is 
 most material to observe. Many 
 substances decrepitate immediately 
 they become hot ; and when that is 
 found to be the case, they should 
 be heated red, under circumstances 
 which will prevent their escape : 
 this may be effected, with the 
 earthy minerals, by wrapping them 
 in a piece of platina foil, and, with 
 the metallic ores, by confining them 
 between two pieces of charcoal, 
 driving the point of the flame 
 through a small groove towards the 
 place where the mineral is fixed, by 
 which means a sort of reverberating 
 furnace may be formed. The prin- 
 cipal phenomena to be noticed are, 
 phosphorescence, ebullition, intu- 
 mescence, the exhalation of vapours 
 having the odour either of sulphur 
 or garlic (the latter arising from 
 the presence of arsenic), decrepita- 
 tion, fusibility ; and, amongst the 
 fusible minerals, whether the pro- 
 duce is a transparent glass, an 
 opaque enamel, or a bead of metal. 
 Having first made some observa- 
 tions on a particle of the mineral 
 alone, either the residue or a fresh 
 piece should be examined with the 
 addition of a flux, more particularly 
 in the case of the ores, as the na- 
 ture of the metal may be generally 
 decided by the colour with which 
 it tinges the substance used. The 
 
BLO 
 
 BLUE. 
 
 BOA 
 
 most eligible flux is glass of borax : 
 a piece about half the size of a j)ea 
 being placed on the charcoal, is to 
 be heated till it melts ; the particle 
 of ore being then taken in a pair of 
 forceps, is to be pressed down in it, 
 and the heat applied; or, should 
 the mineral not be inclined to de- 
 crepitate, it may be laid on the 
 charcoal, and two or three pieces 
 of glass of borax, about the size of 
 a pin's head, placed over it ; and on 
 using the blow-pipe, the whole will 
 form itself into a globular bead. 
 
 Blow-valve, the ' snifting valve ' of a 
 condensing engine. 
 
 Blue, one of the seven primitive co- 
 lours of the rays of light, into which 
 they are divided when refracted 
 through a glass prism. 
 
 Blue-black is a well-burnt and levi- 
 gated charcoal, of a cool, neutral 
 colour, and not differing from the 
 common Frankfort black. Blue- 
 black was formerly much employed 
 in painting, etc. 
 
 Blue carmine is a blue oxide of mo- 
 lybdena, of which little is known 
 as a substance or as a pigment. 
 It is said to be of a beautiful blue 
 colour, and durable in a strong 
 light, but is subject to be changed 
 in hue by other substances, and 
 blackened by foul air: we may 
 conjecture, therefore, that it is not 
 of much value in painting. 
 
 Blue dyes, indigo, Prussian blue, log- 
 wood, bilberry, etc. 
 
 Bluing, the process of heating iron, 
 and some other metals, until they 
 assume a blue colour. 
 
 Blue John, fluor spar, called so by 
 Derbyshire miners. 
 
 Blue ochre is a mineral colour of rare 
 occurrence, found with iron pyrites 
 in Cornwall, and also in North 
 America, and is a subphosphate of 
 iron. What Indian red is to the 
 colour red, and the Oxford ochre 
 to yellow, this is to other blue co- 
 lours. They class in likeness of 
 character: hence it is admirable 
 rather for the modesty and solidity, 
 than for the brilliancy of its colour. 
 
 Blue pigments, found in common, are 
 Prussian blue, mountain blue, Bre- 
 men blue, iron blue, cobalt blue, 
 smalt, charcoal blue, ultramarine, 
 indigo, litmus, and blue cake. 
 
 Blue tint, in colouring, is made of 
 ultramarine and white, mixed to a 
 lightish azure. It is a pleasant 
 working colour, and with it should 
 be blended the gradations in a pic- 
 ture. It follows the yellows, and 
 with them it makes the greens ; 
 and with the red it produces the 
 purples. No colour is so proper 
 for blending down or softening the 
 lights into keeping. In pictures of 
 less value, Antwerp blue may be 
 substituted for ultramarine. 
 
 Blue verditer is a blue oxide of cop- 
 per, or precipitate of the nitrate of 
 copper by lime, and is of a beauti- 
 ful light-blue colour. It is little 
 affected by light ; but time, damp, 
 and impure air turn it green, and 
 ultimately blacken it, changes 
 Vvhich ensue even more rapidly in 
 oil than in water: it is, therefore, 
 Ly no means an eligible pigment in 
 oil, and is principally confined to 
 distemper, painting, and the uses 
 of the paper-stainer, though it. has 
 been found to stand well, many 
 years, in water-colour drawings and 
 crayon paintings, when kept dry. 
 
 Blue vitriol, sulphate of copper. 
 
 Bluff: a bluff-bowed or bluff-headed 
 vessel is one which is full and 
 square forward. 
 
 Blunk, heavy cotton cloth : the term 
 is used in Scotland. 
 
 Board, a substance of wood contained 
 between two parallel planes ; as 
 when the baulk is divided into se- 
 veral pieces by the pit-saw, the 
 pieces are called boards. 
 
 Board, in nautical language, the line 
 over which a ship runs between 
 tack and tack. To board is to en- 
 ter a ship. 
 
 Boarding -floors are those covered 
 with boards : the operation of 
 boarding floors should commence 
 as soon as the windows are in, and 
 the plaster dry. 
 
BOA 
 
 BOILERS. 
 
 BOI 
 
 Boarding-joists, joists in naked floor- 
 ing, to which the boards are fixed. 
 
 Boarding -pike, a pike used by sailors 
 in boarding an enemy's vessel. 
 
 Boasting, in masonry, the paring of a 
 stone with a broad chisel and 
 mallet. 
 
 Boasting, in sculpture or carving, is 
 the rough cutting of a stone to form 
 the outline of a statue or ornament. 
 
 Boats, small open vessels, impelled on 
 the water by rowing or sailing, 
 having different uses, dimensions, 
 etc., either for river or sea service. 
 
 Boat-hook, an iron hook with a sharp 
 point, fixed on a pole, at the extre- 
 mity. 
 
 Boatswain, a warrant officer in the 
 navy, who has the charge of the 
 rigging, and calls the crew to duty. 
 
 Bob, the miner's engine-beam. 
 
 Bob, of a pendulum, is the metallic 
 weight which is attached to the 
 lower extremity of a pendulum-rod. 
 
 Bobstay- holes, those in the fore-part 
 of the knee of the head, for the se- 
 curity of the bobstay. 
 
 Bob-stays, used to confine the bow- 
 sprit down to the stem or the cut- 
 water. 
 
 Bocatorium, anciently a slaughter- 
 house. 
 
 Bodium, a crypt, or subterraneous 
 chapel. 
 
 Body, in physics or natural philoso- 
 phy, any solid or extended palpable 
 substance. 
 
 Body, or solid, in geometry, has three 
 dimensions, length, breadth, and 
 thickness. Bodies are either hard, 
 soft, or elastic. 
 
 Body-plan, in naval architectural 
 drawing, sectional parts showing 
 fore and after parts of a vessel. 
 
 Boeria, anciently a manor-house or 
 large country dwelling, 
 
 Bog, soft, marshy, and spongy matter, 
 or quagmire. Railroads have been 
 made across bogs in Lancashire and 
 in America, by draining, etc., and 
 in the latter by piling as well as 
 draining. 
 
 Bog-iron ore, an iron ore discoverable 
 in boggy land. 
 
 57 
 
 Boiler, a wrought-iron vessel contain 
 ing water, to which heat is applied 
 for the generation of steam. Boilers 
 are made of various forms, accord- 
 ing to the nature of their applica- 
 tion, and are constructed so as to 
 obtain the largest heating surface 
 with the least cubical content. 
 
 Boilers. A boiler for 20-horse power is 
 usually 15 feet long and 6 feet wide ; 
 therefore 90 feet of surface, or 4^ 
 feet to 1 -horse power ; a boiler for 
 1 4-horse power, 60 feet of surface, 
 or 4'3 feet to 1-horse power; but 
 engineers allow 5 feet of surface to 
 1-horse power, and Mr. Hicks, of 
 Bolton, proportions his boilers at 
 the rate of 5 square feet of hori- 
 zontal surface of water to each horse- 
 power : Mr. Watt allows 25 cubic 
 feet of space to each horse-power. 
 
 Boilers. Iron cement is far preferable 
 to any other material for making 
 iron joints : it has the excellent 
 property, that it becomes more 
 sound and tight the longer it stands, 
 so that cemented joints which at 
 first may be a little leaky, soon be- 
 come perfectly tight. The follow- 
 ing is the best mode of preparing 
 this iron cement : take 16 parts of 
 iron filings, free from rust; 3 parts 
 powdered sal-ammoniac (muriate 
 of ammonia) ; and 2 parts of flower 
 of sulphur : mix all together inti- 
 mately, and preserve the compound 
 in a stoppered vessel, kept in a dry 
 place, until it is wanted for use. 
 Then take 1 part of the mixture, 
 add it to 12 parts of clean iron 
 filings, and mix this new compound 
 with so much water as will bring it 
 to the consistence of a paste, hav- 
 ing previously added to the water 
 a few drops of sulphuric acid. In- 
 stead of filings of hammered iron, 
 filings, turnings, or borings of cast 
 iron may be used ; cement, how- 
 ever, made entirely of cast iron is 
 not so tenacious and firm as if of 
 wrought iron ; it sooner crumbles 
 and breaks away. It is better to 
 add a certain quantity, at least one- 
 third, of the latter to the former. 
 
BOI 
 
 BOILERS. 
 
 BON 
 
 There is but little ground to fear 
 for the soundness of a well-riveted 
 iron boiler ; for in time the action 
 of rust and deposit will stop almost 
 any crevices. In order, however, to 
 take all precaution, it is to be re- 
 commended that some clammy sub- 
 stance, such as horse-dung, bran, 
 coarse meal, or potatoes, should be 
 boiled in the vessel before it is used. 
 A very small quantity also of the 
 same kind of substance may be put 
 into the boiler when first set to 
 work : this will find its way into the 
 crevices by the pressure within, 
 and, gradually hardening, will soon 
 render the vessel perfectly sound. 
 
 Boilers. Copper is more tough and 
 less liable to crack than iron, and 
 is a most excellent material for 
 high-pressure boilers : it has, how- 
 ever, a less cohesive power; and 
 therefore a greater thickness of me- 
 tal is necessary to produce an equal 
 strength : but since copper boilers 
 never fly in pieces in case of explo- 
 sion, it is not necessary to be too 
 scrupulous in regard to this point. 
 Even when the metal is thin, espe- 
 cially if the diameter is not great, 
 the use of copper removes all dan- 
 ger of destructive explosion, since 
 at most only a simple tearing asun- 
 der of the metal will ensue. 
 
 Boiling, or ebullition, the agitation of 
 fluids, arising from the action of 
 fire, etc. 
 
 Bole, an argillaceous mineral, having 
 a conchoidal fracture, an internal 
 lustre, and a shining streak. 
 
 Bollards, large posts set in the ground 
 at each side of the docks, to lash 
 and secure hawsers for docking and 
 undocking ships. 
 
 Bollard timbers, in a ship, two tim- 
 bers within the stern, one on each 
 side of the bowsprit, to secure its 
 end. 
 
 Bolognese School, in painting, a Lom- 
 bard school, founded by Caracci. 
 
 Bolognese School, the great painters 
 of which were, Francia Agostino, 
 b. 1558, d. 1601; Domenichino, 
 b. 1581, d. 1641 ; Guido Remi, b. 
 
 58 
 
 1575, d. 1642; Gio. Lanfranco, b. 
 1678, d. 1744 ; Ludovico Caracci, 
 b. 1555, d. 1619; Annibale Ca- 
 racci, b. 1560, d. 1609; Francesco 
 Albani.b. 1578,d. 1660; Guercino, 
 b. 1590, d. 1666. 
 
 Bolognian stone is derived from sul- 
 phate of baryta by calcination and 
 exposure to the rays of the sun. 
 
 Bolster, a piece of timber placed upon 
 the upper or lower cheek, worked 
 up about half the depth of the 
 hawse-holes, and cut away for the 
 easement of the cable, and to pre- 
 vent its rubbing the cheek ; like- 
 wise the solid piece of timber that 
 is bolted to the ship's side, on which 
 the stantients for the linings of the 
 anchors are placed ; or any other 
 small piece fixed under the gun- 
 wale, to prevent the main sheet 
 from being rubbed, etc. 
 
 Bolster, a tool used for punching 
 holes and for making bolts. 
 
 Bolster of a capital, the flank of the 
 Ionic capital. 
 
 Bolt, a cylindrical pin of iron or other 
 metal, used for various purposes of 
 fastening, planking, etc. 
 
 Bolt-auger, an auger of a large size, 
 used by shipbuilders. 
 
 Bolt-rope, the rope to which the edges 
 of sails are sewed, to strengthen 
 them. 
 
 Bolt-screwing machine, a machine for 
 screwing bolts, by fixing the bolt- 
 head to a revolving chuck, and 
 causing the end which it is required 
 to screw to enter a set of dies, which 
 advance as the bolt revolves. 
 
 Bolts, large iron pins. 
 
 Bolts, long cylindrical bars of iron or 
 copper, used to secure or unite the 
 different parts of a vessel ; the prin- 
 cipal ironwork for fastening and 
 securing the ship. 
 
 Bomb-vessel, a strong-built vessel 
 carrying heavy metal for bombard- 
 ment. 
 
 Bomb-ketch, a ship or vessel built 
 with large beams, for carrying and 
 raising of mortars at sea. 
 
 Bonarroti ( Michel angiolo), born 
 1474, pupil of Doinenico Ghir- 
 
BON 
 
 BONING. 
 
 BOR 
 
 landajo, painter, sculptor, and 
 architect : the most eminent of 
 his country for his very great ac- 
 quirements in the arts in which 
 he so eminently practised. 
 
 Bond, in masonry, is that connection 
 of lapping the stones upon one 
 another in the carrying up of the 
 work so as to form an inseparable 
 mass of building. 
 
 Bond, in bricklaying and masonry, is 
 the arrangement or placing of 
 bricks, etc., so as to form a secure 
 mass of building. 
 
 Bonders, Bond-stones, Binding stones, 
 stones which reach a considerable 
 distance into, or entirely through, 
 a wall, for the purpose of binding 
 it together. 
 
 Bond stones, are placed in the thick- 
 ness of a wall, at right-angles to its 
 face, to bind securely together. 
 
 Bond, in carpentry, a term among 
 workmen, to make good bond by 
 fastening two or more pieces to- 
 gether, either tenoned, mortising, 
 or dovetailing. 
 
 Bond timber, pieces of timber used to 
 bind in brickwork especially. The 
 naked flooring being laid, in carry- 
 ing up the second story bond tim- 
 bers must be introduced opposite 
 to all horizontal mouldings, as bases 
 and surfaces. It is also customary 
 to put a row of bond timber in 
 the middle of the story, of greater 
 strength than those for the bases 
 and surfaces. 
 
 Bongrace (a sea term), is a frame of 
 old ropes or junks of cables, laid at 
 the bows, sterns, and sides of ships 
 sailing in cold latitudes, to preserve 
 them from damage by flakes of ice. 
 
 Bone-brown and Ivory-brown, pro- 
 duced by torrefying or roasting 
 bone and ivory, till, by partial 
 charring, they become of a brown 
 colour throughout. 
 
 Boning, in carpentry and masonry, the 
 art of making a plane surface by 
 the guidance of the eye : joiners 
 try up their work by boning with 
 two straight-edges, v\ bicli determine 
 whether it be in or out of winding, 
 
 59 
 
 that is to say, whether the surface 
 be twisted or a plane. 
 
 Bonnet, in navigation, an additional 
 piece of canvas attached to the foot 
 of a jib, or a schooner's foresail, 
 by lacings, taken off in bad weather. 
 
 Bonnets, the cast-iron plates which 
 cover the openings in the valve- 
 chambers of a pump : the openings 
 are made so that ready access can 
 be had when the valves need re- 
 pairing. 
 
 Bonney (mining), a distinct bed of 
 ore, that communicates with no 
 vein. 
 
 Bonnington. In landscape his practice 
 was to sketch in the outline and 
 general character, and then make 
 accurate studies of the local light 
 and shade and colour. 
 
 Boom, in ship-building, a long pole 
 run out from different places in the 
 ship, to extend the bottoms of par- 
 ticular sails, as jib-boom, flying- 
 jib-boom, studding-sail-boom, etc. 
 
 Boomkin, in ship-building, a beam of 
 timber projecting from each bow 
 of a ship, to extend the clue or 
 lower corner of the foresail to wind- 
 ward. 
 
 Boor, a parlour, bedchamber, or in- 
 ner room. 
 
 Booth, a stall or standing in a fair or 
 market. 
 
 Boot-topping, scraping off the grease, 
 or other matter, which may be on 
 a vessel's bottom, and daubing it 
 over with tallow. 
 
 Borax, in chemistry, a salt in appear- 
 ance like crystals of alum ; an arti- 
 ficial salt used for soldering metals. 
 
 Borcer, an instrument of iron, steel- 
 pointed, to bore holes in large rocks, 
 in order to blow them up with gun- 
 powder. 
 
 Bord, anciently a cottage. 
 
 Bore, in hydrography, a sudden and 
 abrupt influx of the tide into a 
 river or narrow strait. 
 
 Boreas, the north wind. 
 
 Borer, a boring instrument, with a 
 piece of steel at the end, called a 
 boring-bolt. 
 
 Boring, the art of perforating or mak- 
 
BOR 
 
 BORING. 
 
 EOT 
 
 ing a hole through any solid body ; 
 as boring the earth for watef; 
 boring water-pipes, either wood, 
 iron, zinc, or lead ; boring cannon, 
 etc. 
 
 Boring. Modern steam-engines depend 
 on the improved method of boring 
 their cylinders. The cylinder to be 
 bored is firmly fixed with its axis 
 parallel to the direction in which 
 the borer is to move : the cutting 
 apparatus moves along a bar of iron 
 accurately turned to a cylindrical 
 form. 
 
 Boring-bar, a bar of a small horizontal 
 boring-machine : it is used for bor- 
 ing the brasses of plummer-blocks, 
 by means of a cutter fixed in it. 
 
 Boring -collar, in turning, a machine 
 having a plate with conical holes 
 of different diameters : the plate is 
 movable upon a centre, which is 
 equidistant from the centres or 
 axes of the conical holes ; the axes 
 are placed in the circumference of 
 a circle. The use of the boring- 
 collar is to support the end of a 
 long body that is to be turned hol- 
 low, and which would otherwise 
 be too long to be supported by a 
 cjiuck. 
 
 Boring-lathe, a lathe used for boring 
 wheels or short cylinders. The 
 wheel or cylinder is fixed on a large 
 chuck, screwed to the mandril of a 
 lathe. 
 
 Boring -mac nine, a machine for turn- 
 ing the inside of a cylinder. 
 
 Boromino (F.), born in Bissano, near 
 the Lago di Lugano, in 1509. He 
 was architect in the service of the 
 family of the Visconti, and was 
 architect of superb taste ; many of 
 his buildings are finely portrayed 
 in M. Letarouilly's great work on 
 Rome. 
 
 Boron, in chemistry, is an olive-green 
 powder, which, heated out of the 
 air, becomes harder, and darker in 
 colour : it burns brilliantly when 
 heated in air or oxygen, forming 
 boracic acid. 
 
 Bosco (Jean de Sacro), a celebrated 
 mathematician of the thirteenth 
 
 60 
 
 century, who was so called from Ho- 
 lywood, a town in England of that 
 name, which was his birth-place. 
 After studying in the University of 
 Oxford, he went to Paris and ac- 
 quired great reputation by his 
 knowledge of mathematics. He has 
 left two works, valuable for their 
 time, one entitled, ' De Sphjera 
 Mundi ; ' the other, ' De Compute 
 Ecclesiastico.' They are printed in 
 one volume. 
 
 Boss, a sculptured keystone or carved 
 piece of wood, or moulded plaster, 
 placed at intervals of ribs or groins 
 in vaulted and flat roofs of Gothic 
 structures. 
 
 Boss, a short trough for holding mor- 
 tar when tiling a roof : it is hung 
 to the laths. 
 
 Bossage, projecting stones laid rough 
 in building, to be afterwards cut 
 into mouldings or ornaments. 
 
 Bosquet, a French expression for a 
 piece of ground in gardens, en- 
 closed by a palisade or high hedge- 
 row of trees, etc. 
 
 Botany Bay oak, resembling in colour 
 full red mahogany, is used as ve- 
 neer for the backs of brushes, turn- 
 ery, etc. 
 
 Bottle-glass, a composition of sand 
 and lime, clay, and alkaline ashes 
 of any kind. 
 
 Bottom - captain, a superintendent 
 over the miners in the bottoms. 
 
 Bottom-heat, artificial temperature, 
 produced in hothouses. 
 
 Bottom-lift, in mining, the deepest 
 or bottom tier of pumps. 
 
 Bottom-rail, in joinery, the lowest 
 rail of a door. 
 
 Bottoms, in mining, the deepest work- 
 ing parts of a mine, wrought either 
 by sloping, driving, or otherwise 
 breaking the lode. 
 
 Bottoms in fork. In Cornwall, when 
 all the bottoms are unwatered, they 
 say, ' the bottoms are in fork ;' 
 and to draw out the water from 
 them, or any dippa, or any other 
 particular part of a mine, is said to 
 be ' forking the water ;' and when 
 accomplished, such dippa, etc., is 
 
BOU 
 
 BOW. BOW 
 
 ' in fork.' Likewise when an en- 
 gine has drawn out all the water, 
 
 Bovey coal, wood-coal found at Bovey, 
 in Devonshire. 
 
 they say, ' the engine 
 
 is in fork.' 
 
 Bow, the round part of a ship forward. 
 
 Boudoir, a small retiring-room. 
 
 Bow, anciently an arch or gateway. 
 
 Boulders, fragments of 
 
 rocks -trans- 
 
 Bow-compass, for drawing arches of 
 
 ported by water, and found on the 
 
 very large aisles ; it consists of a 
 
 sea-shore. 
 
 
 beam of wood or brass with three 
 
 Boulder walls, walls built of the above. 
 
 long screws that bend a lath of 
 
 Boultine, in architecture, a convex 
 
 wood or steel to any arch. The 
 
 moulding, whose periphery is a 
 
 term also denotes small compasses 
 
 quarter of a circle, next below the 
 
 employed in describing arcs too 
 
 plinth in the Doric 
 
 and Tuscan 
 
 small to be accurately drawn by 
 
 orders. 
 
 
 the common compasses. 
 
 Bounds, in mining, signifies the right 
 
 Bow and string bridge, or bow-string 
 
 to tin ore over a given 
 
 district. 
 
 or tension bridge ; in which the 
 
 Boulevard, promenades around a city, 
 
 horizontal thrust of the arch, or 
 
 shaded by avenues of trees. 
 
 trussed beam, is resisted by means 
 
 Bourgeois (Nicolas), an Augustin, was 
 
 of a horizontal tie attached as 
 
 the inventor of the pont-tournant. 
 
 nearly as possible to the chord line 
 
 A reward of 1200 livres a year was 
 
 of the arch. 
 
 offered to him who should invent 
 
 Bow and string beam, a beam so 
 
 a movable bridge to be placed over 
 
 trussed that the tendency of the 
 
 the ditch of the Tuileries. 
 
 straight part to sag when loaded 
 
 Bourse, a public edifice 
 
 for the as- 
 
 is counteracted to some extent by 
 
 semblage of merchants to consult 
 
 the tension upon its two ends, by 
 
 on matters of business or money, 
 
 a bow of wood or metal attached 
 
 an exchange. 
 
 
 to those extremities. 
 
 Boutant ; in architecture, 
 
 an arc-bou- 
 
 Bower cables, for ships. 
 
 tant is an arch, or buttress, serving 
 
 Table showing the different kinds 
 
 to sustain a vault, and 
 
 which is it- 
 
 of best bower cables at present em- 
 
 self sustained by some strong wall 
 
 ployed in the British navy, with the 
 
 or massive pile. 
 
 
 corresponding iron cables, and the 
 
 Bova, anciently a wine-cellar. proof-strain for each : 
 
 
 Best bower hempen 
 
 
 
 Diameter and 
 
 
 
 cables, 
 
 100 fathoms. 
 
 Number 
 f\f 
 
 Breaking 
 
 weight of the bolt 
 
 Strain 
 
 Hates of Ships. 
 
 Cir- 
 cumf. 
 
 Weight. 
 
 01 
 
 threads 
 in each. 
 
 strain by 
 experiment. 
 
 of the iron cable 
 substituted for 
 the preceding. 
 
 for the 
 proof. 
 
 
 in. 
 
 cwt. qr. Ib. 
 
 
 tons. cwt. qr. 
 
 
 tons. 
 
 First-rate, large . 
 
 25 
 
 114 2 7 
 
 3240 
 
 t 
 
 s 
 
 
 middle 
 
 24 
 
 105 2 17 
 
 2988 
 
 < 
 
 ol V 
 
 
 small . 
 
 23 
 
 96 2 27 
 
 2736] 
 
 
 I 2& inches. 
 
 I'Sl 
 
 Second-rate . . 
 
 23 
 
 96 2 27 
 
 2736 J. 
 
 114 
 
 1 218 cwt. 
 
 ' 
 
 Third, large . . 
 
 23 
 
 96 2 27 
 
 2736 J 
 
 
 J 
 
 
 small . . 
 
 22 
 
 89 12 
 
 25201 
 
 
 f 2 inches. 
 
 > 
 
 Fourth, 60 guns . 
 
 21 
 
 80 22 
 
 2268 J 
 
 89 
 
 1186 cwt. 2 qrs. 
 
 /72 
 
 58 do. . 
 
 19 
 
 66 21 
 
 1872 
 
 
 f 1| inch. 
 
 V 
 
 50 do. . 
 
 
 62 1 14 
 
 1764 
 
 . 
 
 I 170 cwt. 2 qrs. 
 
 |63 
 
 Fifth, 48 do. . 
 
 18 
 
 58 2 6 
 
 1656 
 
 63 
 
 \ 
 
 
 46 do. I 
 42 do. J 
 
 174 
 
 56 1 
 
 1584 
 
 
 1 If inch. 
 j 145 cwt. 3 qrs. 
 
 } 
 
 Sixth, 28 do. . 
 
 144 
 
 38 21 
 
 1080 
 
 40 
 
 r If inch. 
 1 87 cwt. 2 qrs. 
 
 } 
 
 Ship, sloop . . 
 
 134 
 
 33 10 
 
 936 
 
 , , 
 
 f Uinch. 
 
 
 Brig, large . . 
 
 134 
 
 33 10 
 
 936 
 
 
 \ 74 cwt. 3 qrs. 
 
 J28 
 
 Ditto small . . 
 
 11 
 
 21 2 15 
 
 612 
 
 
 
 r 14 inch. 
 1 6l cwt. 1 qr. 
 
 }23 
 
 61 
 
BOW 
 
 BOWLS. 
 
 BRA 
 
 From the preceding Table the im- 
 mense advantage of iron cables wfll 
 be distinctly seen, and particularly 
 when it is considered that a hempen 
 cable, on a rocky bottom, is de- 
 stroyed in a few months, while the 
 other will sustain no perceptible 
 injury. 
 
 Bow and string girder, a wrought- 
 iron bow and string girder, pa- 
 tented by Mr. G. Nasmyth. 
 
 Bower, anciently a small enriched 
 chamber for ladies; a private room, 
 or parlour, in ancient castles and 
 mansions. 
 
 Bower, a working anchor, the cable of 
 which is bent and veered through 
 the hawse-hole. 
 
 Bower, in navigation, two anchors 
 thus named from their being car- 
 ried at the bow. 
 
 Boweric, in the East Indies, a well 
 descended by steps. 
 
 Bow-grace, a frame of old rope or 
 junk, placed round the bows and 
 sides of a vessel, to prevent the ice 
 from injuring her. 
 
 Bowge (a sea term), a rope fastened 
 to the middle of the sail, to make 
 it stand closer to the wind. 
 
 Bow-line, in navigation, a rope lead- 
 ing forward from the leach of a 
 square sail, to keep the leach well 
 out, when sailing close-hauled. 
 
 Bowling-alley, a place where the game 
 and exercise of bowling is carried 
 on. 
 
 Bowl, bowling, or bowline (in a ship), 
 a round space at the head of the 
 mast for men to stand in. 
 
 Bowling-green. Bowling, an ancient 
 English game, which was usually 
 attached to the private grounds 
 during the 16th, 17th, and 18th 
 centuries. 
 
 Bowls of silver were used as drinking- 
 glasses are now, before the intro- 
 duction of glass for such purposes ; 
 they were of small sizes, in ' nests' 
 fitting one within another. Of the 
 larger-sized bowl, the most distin- 
 guished are the mazer and the 
 wassail. Mazer is a term applied 
 to large goblets, of every kind of 
 
 62 
 
 material ; but the best authors 
 agree that its derivation is from 
 maeser, which, in Dutch, means 
 maple ; and therefore that a mazer 
 bowl was originally one formed of 
 maple-wood. 
 v Bow-saw, a saw used for cutting the 
 thin edges of wood into curves. 
 
 Bowse, to pull upon a tackle. 
 
 Bowse away, a sea phrase, to pull 
 all together. 
 
 Bowsprit, in ship-building, a large 
 boom or mast which projects for- 
 ward over the stem to carry sail. 
 
 Bowtel, the shaft of a clustered pillar, 
 or a shaft attached to the jambs of 
 a door or window. 
 
 Box, for mitring, a trough for cutting 
 mitres : it has three sides, and is 
 open at the ends, with cuts in the 
 vertical sides at angles of 45 with 
 them. 
 
 Box-drain, an underground drain 
 built of brick and stone, and of a 
 rectangular section. 
 
 Box of a rib-saw, two thin iron plates 
 fixed to a handle, in one of which 
 plates an opening is made for the 
 reception of a wedge, by which it 
 is fixed to the saw. 
 
 Box-haul, to veer a ship in a manner 
 when it is impossible to tack. 
 
 Box the compass, to repeat thirty-two 
 points of the compass in order. 
 
 Boxing-off, throwing the head sails 
 aback, to force the ship's head ra- 
 pidly off the wind. 
 
 Boxings of a window, the cases oppo- 
 site each other on each side of a 
 window, into which the shutters 
 are folded. 
 
 Box-wood is of a yellow colour, in- 
 clining to orange ; is a sound and 
 useful wood, measuring from 2 to 
 6 feet long, and 2^ to 12 inches in 
 diameter : it is much used by wood- 
 engravers; for clarionets, flutes; for 
 carpenters' rules, drawing-scales, 
 etc. Much of it comes from Box 
 Hill, in Surrey, and from several 
 districts in Gloucestershire, also 
 from other parts of Europe. 
 
 Boziga, anciently a house or dwelling. 
 
 Brace, a piece of slanting timber, used 
 
BRA 
 
 BRAMAH'S PRESS. 
 
 BRA 
 
 in truss partitions, or in framed 
 roofs, in order to form a triangle, 
 and thereby rendering the frame 
 immovable : when a brace is used 
 by way of support to a rafter, it is 
 called a strut : braces in partitions 
 and span roofs are always, or should 
 be, disposed in pairs, and placed in 
 opposite directions. 
 
 Brace, an instrument into which a 
 vernier is fixed ; also part of the 
 press-drill. 
 
 Brace, a rope by which a yard is 
 turned about. 
 
 Braces, that security for the rudder 
 which is fixed to the stern-post and 
 to the bottom of a ship. 
 
 Bracket plummer-llock, a support for 
 a shaft to revolve in, formed so 
 that it can be fixed vertically to the 
 frame of a machine, or to a wall. 
 
 Brackets, ornaments : the hair bracket 
 in ship-building is the boundary 
 of the aft-part of the figure of the 
 head, the lower part of which ends 
 with the fore-part of the upper 
 cheek. The console bracket is a 
 light piece of ornament at the fore- 
 part of the quarter-gallery, some- 
 times called a canting-hose. 
 
 Brackets, the cheeks of the carriage 
 of a mortar; a cramping-iron to 
 stay timber- work ; also stays set 
 under a shelf, to support it. 
 
 Bracket-stairs. " The same method 
 must be observed, with regard to 
 taking the dimensions and laying 
 down the plan and section, as in 
 dogling-stairs. In all stairs what- 
 ever, after having ascertained the 
 number of steps, take a rod the 
 height of the story, from the surface 
 of the lower floor to the surface of 
 the upper floor; divide the rod into 
 as many equal parts as there are to 
 be risers ; then, if you have a level 
 surface to work upon below the 
 stairs, try each one of the risers as 
 you go on : this will prevent any 
 defect." 
 
 Brad, a small nail with a projecting 
 head on one edge. 
 
 Brad-awl, the smallest boring tool 
 used by a carpenter ; its handle is 
 
 63 
 
 the frustum of a cone tapering 
 downwards ; the steel part is also 
 conical, but tapering upwards, and 
 the cutting edge is the meeting of 
 two basils, ground equally from 
 each side. 
 
 Brails, in navigation, ropes by which 
 the foot or lower corners of fore- 
 and-aft sails are hauled up. 
 
 Brake, the apparatus used for retard- 
 ing the motion of a wheel by friction 
 upon its periphery. 
 
 Brake, the handle of a ship's pump. 
 
 Brake, a machine used in dressing flax. 
 
 Brake-wheel, the wheel acted upon 
 by a brake. 
 
 Bramah's hydrostatic press consists 
 in the application of water to en- 
 gines, so as to cause them to act 
 with immense force ; in others, 
 to communicate the motion and 
 powers of one part of a machine 
 to some other part of the same 
 machine. 
 
 This press was constructed in 
 Woolwich dockyard for testing 
 iron cables, and the strain is pro- 
 duced by hydrostatic pressure : its 
 amount is estimated by a system 
 of levers balanced on knife-edges, 
 which act quite independently of 
 the strain upon the machine, and 
 exhibit sensibly a change of pres- 
 sure of th of a ton, even when the 
 total strain amounts to 100 tons. 
 
 This proving-machine was con- 
 structed by Messrs. Bramah, of 
 Pirnlico, and is doubtless one of 
 the most perfect of the kind which 
 has been executed. It consists of 
 two cast-iron sides, cast in lengths 
 of 9 feet each, with proper flanges 
 for abutting against each other, 
 and for fixing the whole to sleepers 
 resting on a secure stone founda- 
 tion. The whole length of the 
 frame is 104| feet, equal to th the 
 length of a cable for a first-rate ; so 
 that the cables are tested in that 
 number of detached lengths, which 
 are afterwards united by shackle- 
 bolts. The press is securely bolted 
 down at one end of the frame, and 
 the cylinder is open at both ends. 
 
BRA 
 
 BRASS. 
 
 BRA 
 
 The solid piston is 5 inches ^in 
 diameter in front and 10 inches 
 behind, so that the surface of pres- 
 sure is the difference of the two, viz. 
 
 The system of levers hung on 
 knife-edges is attached to the other 
 end of the frame, and the cable is 
 attached by bolt-links to this and 
 to the end of the piston-rod. The 
 levers being properly balanced, and 
 the cable attached to a short arm 
 rising above the axis, this draws the 
 other arm downwards; and at a 
 distance equal to twelve times the 
 short arm, is a descending pin and 
 ball, acting in a cup placed on the 
 upper part of the arm of the second 
 lever, and this again acls on a third. 
 The first two levers are under the 
 floor, and pass ultimately into an 
 adjacent room, where a scale carry- 
 ing weights is conveniently placed, 
 and the whole combination is such 
 that every pound in the scale 
 is the measure of a ton strain : 
 the whole acts with such precision 
 that th of a pound, more or less, 
 in the scale, very sensibly affects 
 the balance. At the same place 
 is situated a scale, acted upon 
 by the water-pressure from the 
 charge-pipe of the press, and the 
 valve in this pipe is of such dimen- 
 sions that, together with the lever 
 by which it acts, the power is again 
 such that a pound should balance 
 a ton ; but the friction is here so 
 great that it requires several pounds 
 to make a sensible change in the 
 apparent balance, and for this rea- 
 son this scale is never used. The 
 forcing-pumps are in another adja- 
 cent room, and are worked by han- 
 dles, after the manner of a fire en- 
 gine. At first, six pistons are act- 
 ing, and the operation proceeds 
 quickly; but as the pressure and 
 strains increase, the barrels are suc- 
 cessively shut off, till at length the 
 whole power of the men is em- 
 
 64 
 
 ployed on one pair of pumps only, 
 and on this the action is conti- 
 nued till the proofstrain is brought 
 on the cable. A communication is 
 then opened between the cistern 
 and cylinder, and everything is 
 again restored to equilibrium. 
 
 Bramley Fall stone, a sandstone of 
 the Millstone Grit formation quar- 
 ried in the township of Bramley in 
 Yorkshire. 
 
 Branch, in mining, a leader, string, 
 or rib of ore, that runs in a lode ; 
 or if a lode is divided into several 
 strings, they are called branches, 
 whether they contain ore or not : 
 likewise strings of ore which run 
 transversely into the lode are called 
 branches ; and so are all veins that 
 are small, dead or alive, i. e. whe- 
 ther they contain ore or not. 
 
 Branched-worfc, carved and sculp- 
 tured leaves and branches in monu- 
 ments and friezes. 
 
 Branches, anciently the ribs of groin- 
 ed ceilings. 
 
 Brandishing or Brattishing, a term 
 used for carved-work, as a crest, 
 battlement, or other parapet. 
 
 Brandrith, a fence or rail round the 
 opening of a well. 
 
 Brass, a factitious metal, made of 
 copper and zinc. 
 
 Brass, in the middle ages, a plate of 
 metal inserted or affixed to a flat 
 gravestone. 
 
 Brasses (Sepulchral], monumental 
 plates of brass or mixed metal, an- 
 ciently called latten, inlaid on large 
 slabs of stone, which usually form 
 part of the pavement of a church, 
 and represent in their outline, or 
 by lines engraved upon them, the 
 figure of the deceased. 
 
 Brattishing, anciently, carved open- 
 work. 
 
 Bray, anciently, a bank or earthen 
 mound. 
 
 Brazil-wood, the wood of Ccesalpinia 
 echinata, which yields a red dye : 
 it is imported principally from Per- 
 nambuco : the tree is large, crook- 
 ed, and knotty ; and the bark is 
 thick, and equals the third or fourth 
 
BRA 
 
 BREAK. 
 
 BRE 
 
 of its diameter. Its principal use 
 is for dyeing : the best pieces are 
 selected for violin-bows and turn- 
 ery. 
 
 Braziletto-wood is of a ruddy orange 
 colour, principally used for dyeing, 
 and for turnery and violin-bows. 
 
 Brazing, the soldering together of 
 edges of iron, copper, brass, etc., 
 with an alloy of brass and zinc 
 called spelter solder. 
 
 Breadth is applied to painting when 
 the colours and shadows are broad 
 and massive, such as the lights and 
 shadows of the drapery ; and when 
 the eye is not checked and dis- 
 tracted by numerous little cavities, 
 but glides easily over the whole. 
 Breadth of colouring is a promi- 
 nent character in the painting of 
 all great masters. 
 
 Break, in shipping. To break bulk, is 
 to begin to unload. 
 
 Break, a projection or recess from the 
 surface or wall of a building. 
 
 Break joint, constructively, to dis- 
 allow two joints to occur over each 
 other. 
 
 Breaker, a small cask for water. 
 
 Breaking down, in sawing, is dividing 
 the baulk into boards or planks. 
 
 Breaking joint, in joinery, is not to 
 allow two joints to come together. 
 
 Breakwater, a human contrivance 
 to ward off and diminish the force 
 of waves, to protect harbours, sta- 
 tions, etc., from the violence of tem- 
 pestuous gales. Some stupendous 
 works have been executed for these 
 purposes, especially that at Ply- 
 mouth, by the late John Rennie. 
 
 Breaming, cleaning a ship's bottom 
 by burning. 
 
 Breast, in mining, the face of coal- 
 workings. 
 
 Breast-fast, a rope used to confine a 
 vessel sideways to a wharf or to 
 some other vessel. 
 
 Breast-hooks, pieces of compass or 
 knee-timber, placed withinside a 
 ship, to keep the bows together. 
 The deck-holes are fayed to the 
 timbers, and placed in the direction 
 of the decks : the rest are placed 
 
 65 
 
 one between each deck, and as 
 many in the hold as are thought 
 needful ; all of which should be 
 placed square with the body of the 
 ship, and fayed on the planks. 
 Breast-hooks are the chief security 
 to keep the ship's bows together ; 
 therefore they require to be very 
 strong and well secured. 
 
 Breast-knees are placed in the for- 
 ward part of a vessel, across the 
 stem, to unite the bows on each 
 side. 
 
 Breast-plate, that in which the end 
 of the drill opposite the boring 
 end is inserted. 
 
 Breast-rail, the upper rail of the bal- 
 cony or of the breastwork on the 
 quarter-deck. 
 
 Breast-rope, a rope passed round a 
 man in the chains, while taking 
 soundings. 
 
 Breast-wheel, in mill- work, a form of 
 water-wheel in which the water is 
 delivered to the float-boards at a 
 point somewhat between the bot- 
 tom and top. Buckets are seldom 
 employed on breast-wheels. 
 
 Breastwork, the stantients with rails 
 on the quarter-deck and forecastle. 
 The breastwork fitted on the up- 
 per deck of such ships as have no 
 quarter-deck serves to distinguish 
 the main-deck from the quarter- 
 deck. 
 
 Breastwork, a mass of earth raised 
 to protect troops from the fire of 
 an enemy. 
 
 Breech, the angle of a knee-timber, 
 the inside of which is called the 
 throat. 
 
 Breechings, in a ship, are ropes by 
 which the guns are lashed fast or 
 fastened to the ship's side. 
 
 Breeze, small ashes and cinders used 
 instead of coal for the burning of 
 bricks. 
 
 Breostweall, anciently, a breast-high 
 wall. 
 
 Bressummer, a beam supporting a su- 
 perincumbent part of an exterior 
 wall, and running longitudinally 
 below that part. 
 
 Brest, in architecture, is that co- 
 
BRE 
 
 BRICKS. 
 
 BRI 
 
 lumn which is called the thorus or 
 tore. 
 
 Bretachia, anciently, wooden towers, 
 attached to fortified towns. 
 
 Brewhouse, a building specially built 
 and appropriated for the brewing 
 of beer. 
 
 Brick. " Let us make brick, and 
 burn them thoroughly. And they 
 had brick for stone, and slime had 
 they for mortar." Gen. xi. 3. 
 
 Bricks are a kind of factitious stone, 
 composed of argillaceous earth, and 
 frequently a certain portion of sand, 
 and cinders of sea-coal (called 
 breeze), tempered together with 
 water, dried in the sun, and burnt 
 in a kiln, or in a heap or stack 
 called a clamp. For good brick- 
 making, the earth should be of the 
 purest kind, dug in autumn, and 
 exposed during the winter's frost ; 
 this allows the air to penetrate, 
 and divide the earth particles, and 
 facilitates the subsequent opera- 
 tions of mixing and tempering. 
 
 The Romans made bricks of va- 
 rious sizes, from 1 foot to 2 feet in 
 length, from 7 inches to 9 inches in 
 breadth, and from 3^ inches to 1$ 
 in thickness. Roman bricks found 
 in the old Roman wall at Veru- 
 lam, compared with modern bricks, 
 show the superiority of the old 
 to the new, the Roman bricks be- 
 ing lighter and better burnt than 
 the modern. 
 
 The brick remains of the period 
 of the Roman empire are more en- 
 tire than the stone. Bricks were 
 found at Toulouse, quite sharp at 
 the edges, and not altered by time ; 
 they measured 14 inches long, 
 9 inches broad, and 1 thick. 
 These bricks formed the founda- 
 tion all around the building. The 
 arches were formed of them for 
 entrances ; and round, large, water- 
 worn pebbles of quartz, with mor- 
 tar, formed the walls of the Circus, 
 resting on the brick arches. 
 
 Mr. Layard, in his work on Ni- 
 neveh, says "The soil, an alluvial 
 deposit, was rich and tenacious: the 
 
 66 
 
 builders moistened it with water, 
 and adding a little chopped straw, 
 that it might be more firmly bound 
 together, they formed it into 
 squares, which, when dried by the 
 heat of the sun, served them as 
 bricks. In that climate, the pro- 
 cess required but two or three days. 
 Such were the earliest building 
 materials, and as they are used to 
 this day, almost exclusively, in the 
 same country. 
 
 "The Assyrians appear to have 
 made much less use of bricks baked 
 in the furnace than the Babylo- 
 nians, no masses of brickwork, 
 such as are everywhere found in 
 Babylonia Proper, existing to the 
 north of that province. Common 
 clay moistened with water, and 
 mixed with a little stubble, formed, 
 as it does to this day, the mortar 
 used in buildings ; but, however 
 simple the materials, they have suc- 
 cessfully resisted the ravages of 
 time, and still mark the stupendous 
 nature of the Assyrian structures. 
 
 " This mode of brick-making is 
 described by Sanchoniathon : The 
 people of Tyre invented the art of 
 brick-making and of building of 
 huts; after them came two brothers: 
 one of them, Chrysor or Hyphaes- 
 tus, was the first who sailed in 
 boats ; his brother invented the way 
 of making walls with bricks. From 
 the generation were born two 
 youths, one called Technites and 
 the other Genius Autochthon. They 
 discovered the method of mingling 
 stubble with the loam of the bricks, 
 and drying them in the sun ; they 
 also invented tiling." 
 Bricks. Some of Palladio's finest ex- 
 amples are of brick : the cortile of 
 the Carita at Venice is an instance. 
 The interiors of the Redentore and 
 St. Giorgio, in the same city, have 
 but a coat of plaster on them ; the 
 beautiful Palazzo Thiene at Vicenza, 
 at least that part which was exe- 
 cuted, is left with its rockworked 
 basement in brickwork chipped out. 
 Form alone fastens on the mind in 
 
BRI 
 
 BRIDGE. 
 
 BRI 
 
 works of art ; the rest is meretri- 
 cious, if used as a substitute to su- 
 persede this grand desideratum. 
 
 Brick-axe, used for axing off the 
 soffits of bricks to the saw-cuttings, 
 and the sides to the lines drawn : 
 as the bricks are always rubbed 
 smooth after axing, the more truly 
 they are axed, the less labour there 
 will be in rubbing. 
 
 Brick groins, the intersecting or meet- 
 ing of two circles upon their dia- 
 gonal elevations, drawn upon the 
 different sides of a square, whose 
 principal strength lies in the united 
 force of elevation divided by geo- 
 metrical proportions to one certain 
 gravity. 
 
 Bricklaying, the art by which bricks 
 are joined and cemented, so as to 
 adhere as one body. This art, in 
 London, includes the business of 
 walling, tiling, and paving with 
 bricks or tiles. 
 
 Brick-nogging, brickwork carried up 
 and filled in between timber fra- 
 ming. 
 
 Brick trimmer, a brick arch abutting 
 upon the wooden trimmer under 
 the slab of a fire-place, to prevent 
 the communication of fire. 
 
 Brick-trowel, a tool used for taking up 
 mortar and spreading it on the top 
 of a wall, to cement together the 
 bricks, etc. 
 
 Bridge, a constructed platform, sup- 
 ported at intervals, or at remote 
 points, for the purpose of a road- 
 way over a strait, an inlet or arm 
 of the sea, a river or other stream 
 of water, a canal, a valley or other 
 depression, or over another road : 
 it is distinguished from a cause- 
 way, or embanked or other con- 
 tinuously supported roadway, and 
 from a raft, by being so borne at 
 intervals or at remote points. 
 Constructions of the nature and 
 general form and arrangement of 
 bridges, such as aqueducts and 
 viaducts ; the former, being to lead 
 or carry streams of water or canals, 
 and the latter, to carry roads or 
 railways upon the same, or nearly 
 
 the same level, over depressions, 
 are in practice considered as bridges, 
 although they are not such in the 
 commonly received sense of the 
 term. Taken, however, in the 
 sense which the most plausible ety- 
 mology that has been suggested of 
 the term would require, the word 
 'bridge' being formed by prefixing 
 the constructive be to ridge, a 
 bridge is an elevated construction 
 upon, or over a depression, and 
 between depressed points. 
 
 There are bridges built of the 
 materials, stone, brick, iron, timber, 
 wire, and on the principles of sus- 
 pension ; for the explanation of 
 which, see the word Suspension. 
 
 The bridge across the Zab, at 
 Lizari, is of basket-work. Stakes 
 are firmly fastened together with 
 twigs, forming a long hurdle, reach- 
 ing from one side of the river to 
 the other. The two ends are laid 
 upon beams, resting upon piers on 
 the opposite banks. Both the 
 beams and the basket-work are 
 kept in their places by heavy stones 
 heaped upon them. Animals, as 
 well as men, are able to cross over 
 this frail structure, which swings 
 to and fro, and seems ready to give 
 way at every step. These bridges 
 are of frequent occurrence in the 
 Tiejari mountains. 
 
 Bridges. The principal object to be 
 observed in forming the plan of a 
 bridge, is to give a suitable and 
 convenient aperture to the arches, 
 so as to afford a free vent to the 
 waters of sudden floods o-r inunda- 
 tions, and to secure the solidity and 
 duration of the edifice by a skilful 
 construction. The solidity of a 
 bridge depends almost entirely on 
 the manner in which its foundations 
 are laid. When these are once pro- 
 perly arranged, the upper part may 
 be erected either with simplicity 
 or elegance, without impairing in 
 any degree the durability of the 
 structure. Experience has proved 
 that many bridges either decay, or 
 are swept away by sudden floods, 
 
BRI 
 
 BRITTLENESS. 
 
 BRO 
 
 by reason of the defective mode of 
 fixing their foundations, while very 
 few suffer from an unskilful con- 
 struction of the piles or arches. 
 This latter defect, however, is easy 
 of correction, nor is it difficult 
 to prevent the consequences that 
 might be expected from it. 
 
 In the projection of a bridge, 
 five principal points are necessary 
 to be considered, first, the choice 
 of its position or locality ; secondly, 
 the vent, or egress that must be 
 allowed to the river ; thirdly, the 
 form of the arches ; fourthly, the 
 size of the arches ; fifthly, the 
 breadth of the bridge. 
 
 Bridge-board, or notch-board, a board 
 on which the ends of the steps of 
 wooden stairs are fastened. 
 
 Bridged gutters are made with boards 
 supported by bearers, and covered 
 above with lead. 
 
 Bridge-stone, a stone laid from the 
 pavement to the entrance -door of 
 a house, over a sunk area, and sup- 
 ported by an arch. 
 
 Bridging -floors, floors in which bridg- 
 ing-joists are used. 
 
 Bridging-joists are the smallest beams 
 in naked floorings, for supporting 
 the boarding for walking upon. 
 
 Bridging-pieces, pieces placed be- 
 tween two opposite beams, to pre- 
 vent their nearer approach, as 
 rafters, braces, struts, etc. 
 
 Bridle, the spans of rope attached to 
 the leaches of square sails, to which 
 the bowlines are made fast. 
 
 Bridle-cable, in navigation. When 
 a vessel is moored by laying down 
 a cable upon the ground, with an 
 anchor at each end, then another 
 cable attached to the middle of the 
 ground cable is called bridle-cable. 
 
 Bridle-part, the foremost part, used 
 for stowing the anchors. 
 
 Brig, a square-rigged vessel with two 
 masts. 
 
 Brine-pump, the pump in a steam- 
 ship, used occasionally for drawing 
 off a sufficient quantity of water, to 
 prevent the salt from depositing in 
 the boiler. 
 
 68 
 
 Brettingham (M.), an architect of 
 some eminence of more than a cen- 
 tury ago ; built Norfolk House, in 
 St. James's Square, in 1742; Lang- 
 ley Park, in Norfolk, in 1740-44, 
 
 / etc. 
 
 Brittleness, in iron, is a want of tena- 
 city or strength, so as to be easily 
 broken by pressure or impact : 
 when iron is made too hot, so as 
 to be nearly in a state of fusion, 
 or so hard as to resist the action 
 of the file, this is called the dispo- 
 sition of cast iron. 
 
 Broach, an old English term for a 
 spire ; still in use in some parts of 
 the country to denote a spire 
 Springing from the tower without 
 any intermediate parapet. 
 
 Broach-to, to fall off so much, when 
 going free, as to bring the wind 
 round on the other quarter, and 
 take the sails aback. 
 
 Broadside, the whole side of a vessel. 
 
 Broken back, the state of a vessel 
 when she is so loosened as to droop 
 at each end. 
 
 Bromine, in chemistry, is found com- 
 bined with silver in a few ores, also 
 in sea-water and salt-springs ; as 
 bromide of potassium, sodium, or 
 magnesium. 
 
 Brontern, in Greek architecture, bra- 
 zen vessels placed under the floor 
 of a theatre, with stones in them, 
 to imitate thunder. 
 
 Bronze, a compound metal, made of 
 from 6 to 12 parts of tin and 100 
 parts of copper. 
 
 Brood, in mining, any heterogeneous 
 mixture among tin or copper ore, 
 as Mundick, Black Jack, etc. 
 
 Browning, a process by which the 
 surfaces of articles of iron acquire 
 a shining brown lustre : the mate- 
 rial used to produce this is the 
 chloride of antimony. 
 
 Brown (Sir Samuel), Captain, R.N. 
 engineer of the chain-pier at 
 Brighton; he was the first to in- 
 troduce the bar-link. 
 
 Sir S. Brown has stated that at 
 Brighton he found the impetus 
 of the waves during heavy gales 
 
BRO 
 
 BUFFET. 
 
 BUF 
 
 was " equal to SOlbs. to a foot upon 
 a cylindrical column of 12 inches 
 diameter." The hydrostatical pres- 
 sure of a wave only 1^ foot high 
 is equal to 801b. upon a square 
 foot. 
 
 Brown ink. Various compounds were 
 used in sketching by Claude, Rem- 
 brandt, and many of the old mas- 
 ters, the principal of which were 
 solutions of bistre and sepia. 
 
 Brown ochre, Spruce ochre, or Ochre 
 de Rue, a kind of dark-coloured 
 yellow ochre : it is much em- 
 ployed, and affords useful and per- 
 manent tints. This and all natural 
 ochres require grinding and wash- 
 ing over, to separate them from 
 extraneous substances ; and they 
 acquire depth and redness by burn- 
 ing. 
 
 Brown-pink, a fine glazing colour 
 having but little strength of body. 
 In the flesh, it should never join or 
 mix with the lights, because this 
 colour and white antipathize and 
 mix of a warm dirty hue ; for which 
 reason their joinings should be 
 blended with a cold middle tint. 
 
 Brown-post, a name given by some 
 builders to a beam laid across a 
 building. 
 
 Brown spar, a magnesian carbonate 
 of lime, tinged by oxide of iron and 
 manganese. 
 
 Bruiser, a concave tool used in grind- 
 ing the specula of telescopes. 
 
 Brunswick green, a pigment com- 
 posed of carbonate of copper with 
 chalk or lime. 
 
 Brush-wheels are used in light ma- 
 chinery, to turn each other by 
 means of bristles or brushes fixed 
 to their circumference. 
 
 Buata, anciently an arch of chamber ; 
 a crypt. 
 
 Bucca, anciently an almonry. 
 
 Bucentaur, the name of the once ce- 
 lebrated galley of Venice, used by 
 the Doge on Ascension-day, to ce- 
 lebrate the wedding of the Adria- 
 tic, by dropping a ring into that sea. 
 
 Backers, in mining, bruisers of the 
 ore. 
 
 G9 
 
 Buckets, in water-wheels, a series of 
 cavities placed on the circumfer- 
 ence of the wheel, and into which 
 the water is delivered, to set the 
 wheel in motion. By the revolu- 
 tion of the wheel the buckets are 
 alternately placed so as to receive 
 the water, and inverted so as to 
 discharge it, the loaded side al- 
 ways descending. 
 
 Bucking, in mining, a term applied to 
 a method of breaking the poor foul 
 copper ore smaller by hand, with 
 small flat irons, called bucking- 
 irons, into order to wash and se- 
 parate the pure ore from the use- 
 less waste : the same term is used 
 in the lead-mines ; but Pettus, in 
 his ' Plata Miner,' gives it the sig- 
 nification of washing or wet-stamp- 
 ing ores. 
 
 Bucking-iron, in mining, the tool with 
 which the ore is pulverized. 
 
 Buckler, a shield of armour, anciently 
 used in war. 
 
 Bucklers, in ships, blocks of wood 
 made to fit in the hawse-holes, or 
 holes in the half-ports, when at 
 sea. 
 
 '"^Bucranes, in sculpture, the heads of 
 oxen, flayed and lacerated, some- 
 times represented on friezes. 
 
 Buddie, in mining, a pit dug in the 
 earth near the stamping-mill, 7 feet 
 long, 3 feet wide, and 2 feet 
 deep, where the stamped tin is cu- 
 riously washed from its impuri- 
 ties by water constantly running 
 through the huddle, while a boy, 
 called a buddle-boy, is standing 
 in the body of it, and working 
 both with a shovel and with his 
 feet. 
 
 Budget, a pocket used by tilers for 
 holding the nails in lathing for 
 tiling. 
 
 Buffers, rods with enlarged ends or 
 striking-blocks projecting from the 
 ends of the frame of a railway 
 carriage, and attached to springs, 
 for deadening the shocks received 
 from the engines. 
 
 Buffet, a table with long narrow 
 shelves over it ; a convenient 
 
BUH 
 
 BUILDINGS. 
 
 BUL 
 
 piece of furniture for a sitting 
 room. 
 
 Buhl, unburnished gold. 
 
 Buhl-work, ornamental furniture, in 
 which tortoise-shell is inlaid with 
 wood and brass. 
 
 Builder, a term applied both in civil 
 and naval architecture : in the for- 
 mer the builder is mostly employed 
 under the superintendence of an 
 architect, by contract, or at mea- 
 sure and value ; in the latter, under 
 the naval architect, mostly by 
 contract. 
 
 Building, the art which comprises all 
 the operations of an architect in 
 building with stone, brick, timber, 
 iron, cement, etc. 
 
 Buildings. Of the aspects best adapted 
 to convenience and health, for the 
 different kinds of buildings, Vitru- 
 vius writes : " The principles which 
 should be attended to in allotting 
 to each kind of building an appro- 
 priate aspect remain to be explain- 
 ed : the winter eating-rooms and 
 baths ought to face the winter- 
 west, because the use of them re- 
 quires that they should be light at 
 the time of the sun's setting : be- 
 sides which, the western sun, be- 
 ing immediately opposite to them, 
 renders their temperature mild at 
 the close of the day. The sleeping 
 apartments and libraries should be 
 made to front the east, because the 
 morning light is necessary for them; 
 and books are better preserved 
 when the air and light are received 
 from that quarter. When libraries 
 have a southern or western aspect, 
 they admit those winds which, at 
 the same time that they carry with 
 them moths, instil also damp va- 
 pours into the books, which, in 
 process of time, cause their decay. 
 The vernal and autumnal triclinia 
 should face the east, because the 
 windows being turned from the 
 sun's rays, whose heat increases as 
 the sun advances towards the west, 
 their temperature is cool at the 
 hours they are generally used. The 
 summer triclinia should front the 
 
 70 
 
 north ; because, having that aspect, 
 they will be least exposed to the 
 sun, and the temperature of the 
 apartments will be grateful, at the 
 same time that it is conducive to 
 health. No other aspect possesses 
 equal advantages ; for the sun, dur- 
 ing the solstice, would render the 
 air of all others sultry. This as- 
 pect is necessary for pinacothecffi 
 and the apartments in which the 
 pursuits of embroidery and paint- 
 ing are followed, because the 
 colours used in works of this 
 kind retain their brightness longer 
 when exposed to an equable and 
 regular light." Wilkins's Vit. 
 p. 220. 
 
 Buildings Act, an Act of Parliament 
 passed in the 18th and 19th of 
 Victoria, to regulate the construc- 
 tion of buildings generally, and 
 appurtenances thereto, and to de- 
 termine their supervision by dis- 
 trict surveyors and referees. 
 
 Building of beams, the joining of two 
 or several pieces of timber together 
 in one thickness, and of several 
 pieces in one length, by means of 
 bolts, so as to form a beam of given 
 dimensions, which it would be im- 
 possible to obtain from a single 
 piece of timber. 
 
 Baleuteria, among the Greeks, coun- 
 cil-chambers or public halls. 
 
 Bulge, that part of a ship which 
 bulges out at the floor-heads, to 
 assist the ship when taking the 
 ground. 
 
 Bulge-way, a large piece of timber, 
 or pieces bolted together, making 
 one solid piece, placed under the 
 bulge of a ship, to support her 
 launch. The support of the bulge- 
 ways to lie on is called ways, which 
 sometimes are placed straight and 
 sometimes cumber : but if they do 
 cumber, it should be truly circu- 
 lar; though sometimes the curve 
 is quicker at the lower part, but 
 this is liable to strain the sheer of 
 the ship. Their extreme distance 
 is generally about one-third the 
 breadth of the ship, but this must 
 
BUL 
 
 BURDEN. 
 
 BUR 
 
 depend on the form of the mid- 
 ship bend. 
 
 Bulk,ihe contents of the hold of a ship. 
 
 Bulkar, a beam or rafter. 
 
 Bulk-heads, partitions built up in se- 
 veral parts of a ship, to form and 
 separate the various apartments. 
 
 Bullantic, so-called ornamental capi- 
 tal letters, used in apostolic bulls. 
 
 Bullen-nails, such as have roundheads 
 with short shanks, turned and lac- 
 quered, used principally for hang- 
 ings of rooms. 
 
 Bullet-wood, from the West Indies, 
 is the produce of a large tree with 
 a white sap ; is of a greenish ha- 
 zel, close and hard ; used in the 
 country for building purposes. 
 
 Bullet-wood, another species, from 
 Berbice, is of a hazel-brown colour, 
 adapted to general and eccentric 
 turning. 
 
 BulCs-eye, a small circular aperture 
 for the admission of light or air. 
 
 Bull's-eye, a small oval block of hard 
 wood without sheaves, having a 
 groove round the outside, and a 
 hole in the middle. 
 
 Bulwarks, the woodwork round a 
 vessel, above her deck, consisting 
 of boards fastened to stanchions 
 and timber-heads. 
 
 Bumboats, those which lie alongside 
 a vessel in port with provisions for 
 sale. 
 
 Bumpkins, pieces fitted above the 
 main-rail in the head, which ex- 
 tend nearly as far forward as the 
 fore-part of the knee of the head, 
 and are for the use of hauling down 
 the fore-tack. 
 
 Bunch, or Bunchy: a mine that is 
 sometimes rich and at other times 
 poor, is said to be lunchy. 
 
 Bunch, or Squat, in mining, a quan- 
 tity of ore, of small extent, more 
 than a stone and not so much as a 
 course : a mine is said to be bunchy 
 when these are found in place of a 
 regular lode. 
 
 Bundle -pillar, a column or pier, with 
 others of small dimensions attached 
 to it. 
 
 Bunny, in mining, of tin or copper 
 
 71 
 
 ore ; a sombrero in Alonzo Barba ; 
 a pipe of ore ; a great collection 
 of ore without any vein coming into 
 or going out from it. 
 
 Bunt of a sail, the middle part formed 
 into a bag or cavity, that it may 
 gather more wind. 
 
 Buntine, thin woollen stuff, of which 
 a ship's colours are made. 
 
 Bunt-line cloth, the lining sewed up 
 the sail in the direction of the 
 bunt-line, to prevent the rope from 
 chafing the sail. 
 
 Bunt-lines, ropes fastened to cringles 
 on the bottoms of the square sails, 
 to draw them up to their yards. 
 
 Buoy, a cask, or block of wood, fast- 
 ened by a rope to an anchor, to 
 point out shoals or particular spots. 
 
 Burden, in mining, the tops or heads 
 of Streamwork which lie over the 
 stream of tin, and which must be 
 first cleansed. 
 
 Burdon, a pilgrim's staff. 
 
 Bureau, a chamber or office for the 
 transaction of state or business af- 
 fairs. 
 
 ' -'Surges, the Persian word for Towers, 
 evidently the same as the Gothic 
 burgh ; a fortified dwelling or en- 
 closed town. Gird or gard is in 
 Persian a city or fortress, which 
 approximates to garth, an enclo- 
 sure in the Gothic : hence garden. 
 But a castle, comprehendingtowers 
 and walls, is in Persian calaa. 
 
 Burgundy pitch, a resin collected 
 from the spruce fir. 
 
 Burgus, anciently a number of houses 
 protected by a fortress. 
 
 Burgward, anciently the custody or 
 
 keeping of a castle. 
 * Burgwork, anciently applied to a 
 castle or borough. 
 
 Burin, an engraver's instrument ; a 
 graver. 
 
 Burners, for gas-light. Coal gas has 
 now been used for the purposes of 
 artificial illumination nearly fifty 
 years, and the burners sanctioned 
 by the companies at the present 
 day are of several shapes. 
 
 Carburetted hydrogen of the spe- 
 cific gravity '390 (which is about 
 
BUR 
 
 BURNERS. 
 
 BUR 
 
 the density of gas when arrived at 
 the point where it has to be burnt) 
 requires two volumes of pure oxy- 
 gen for its complete combustion 
 and conversion into carbonic acid 
 and water. Atmospheric air con- 
 tains, in its pure state, twenty per 
 cent, of oxygen, in populous 
 towns less ; but twenty per cent, 
 may be taken as a fair average : 
 1 cubic foot of carburetted hydro- 
 gen then requires for its proper 
 combustion 10 cubic feet of air ; if 
 less be admitted on to the flame, a 
 quantity of free carbon will escape 
 (from its not finding a proper vo- 
 lume of oxygen for conversion into 
 carbonic acid), and be deposited 
 in the form of dense black smoke. 
 When the flame from an Argand 
 burner is turned up high, the air 
 which rushes through the interior 
 ring becomes decomposed before it 
 can reach the air on the top of the 
 flame, which consequently burns 
 in one undivided mass, the gas 
 being in part unconsumed, the 
 products unconverted, and carbon 
 deposited abundantly. 
 
 If an excess of air is admitted, it 
 would appear at first to be of no 
 consequence, but it will be found 
 that the quantity of nitrogen ac- 
 companying this excess has a ten- 
 dency to extinguish the flame, while 
 it takes no part in the elective affi- 
 nity constantly going on between 
 the several elementary gases, viz. 
 hydrogen, oxygen, and the vapour 
 of carbon ; and also that the quan- 
 tity of atmospheric air passing 
 through the flame unchanged, tends 
 to reduce the temperature below 
 that necessary for ignition, and 
 therefore to diminish the quantity 
 of light. For the proper combus- 
 tion of the gas, neither more nor 
 less air than the exact quantity re- 
 quired for the formation of carbonic 
 acid and water can be admitted 
 through the flame without being 
 injurious. It is not possible practi- 
 cally to regulate the supply of air 
 to such a nicety : it is preferred 
 
 72 
 
 therefore to diminish the quantity 
 of light by having a slight excess oi 
 air rather than to produce smoke 
 by a deficiency, the former being 
 unquestionably the least evil. 
 
 Burnet (James), a landscape painter : 
 died in 1816, aged 28 years. 
 
 Burning-glass, a glass lens, which, 
 being exposed directly to the sun, 
 refracts the rays which fall upon 
 it into a focus. 
 
 Burning-house, the furnace in which 
 tin ores are calcined, to sublime 
 the sulphur from pyrites : the latter 
 being thus decomposed, are more 
 readily removed by washing. 
 
 Burnisher, a tool used for smoothing 
 and polishing a rough surface. A- 
 gates, polished steel, ivory, etc. 
 are used for burnishing. 
 
 Burnt Carmine is, according to its 
 name, the carmine of cochineal par- 
 tially charred till it resembles in 
 colour the purple of gold, for the 
 uses of which in miniature anc 
 water painting it excels. 
 
 Burnt Sienna earth is, as its name 
 implies, the Terra di Sienna burnt 
 and is of an orange-russet colour. 
 
 Burnt Umber, a pigment obtainec 
 from a fossil substance, which wher 
 burnt assumes a deeper and more 
 russet hue : it contains manganese 
 and iron, and is very drying in oil 
 in which it is employed as a dryer 
 It is a fine warm brown, and a gooc 
 working strong colour, of great use 
 for the hair of the human head, anc 
 mixes finely with the warm shade 
 
 Burnt Verdigris is an olive-coloured 
 oxide of copper deprived of acid, 
 It dries well in oil, and is more 
 durable, and in other respects an 
 improved and more eligilfle pig- 
 ment than in its original state. 
 
 Burre-stone, a mill-stone which is 
 almost pure silex : the best kind 
 is of a whitish colour. 
 
 Burrock, a small weir or dam, where 
 wheels are laid in a river for catch- 
 ing fish. 
 
 Burrow, in mining, the heap or heaps 
 of attle, deads, or earth (void oi 
 ore), which are raised out of a mine, 
 
BUR 
 
 BYZANTINE ARCHITECTURE. 
 
 BYZ 
 
 and commonly lie around the 
 shafts ; any heap or hillock of 
 deads or waste. 
 
 Burr-pump, a bilge-pump worked by 
 a bar of wood pulled up and down 
 by a rope fastened by the middle. 
 
 Bursa, a bag ; a purse used in the 
 middle ages for the purposes of a 
 little college or hall for students. 
 
 Bursar, one to whom a stipend is 
 paid cut of a fund set apart for poor 
 students ; the treasurer of a college. 
 
 Bursary, the treasury of a college. 
 
 Burthen, the weight or measure of 
 capacity of a ship. Multiply the 
 length of the keel, the inner mid- 
 ship breadth, and the depth from 
 the main deck, to the plank joining 
 the keelson together ; and the pro- 
 duct, divided by 94, gives the ton- 
 nage or burthen. 
 
 Burton, a manor; a manor-house. 
 
 Burton, in a ship, a small tackle of 
 two single blocks, named from the 
 inventor. 
 
 Bush, in machinery, a piece of metal 
 fitted into the plummer-block of a 
 shaft in which the journal turns. 
 The guide of a sliding-rod also 
 bears the same name. 
 
 Bush, a circular piece of iron or other 
 metal, let into the sheaves of such 
 blocks as have iron pins, to prevent 
 their \yearing. 
 
 Bushel, a dry measure of 8 gallons or 
 4 pecks. 
 
 Bush-harrow, an implement used in 
 harrowing grass lands. 
 
 Buskin, a high shoe or boot worn 
 anciently, in tragedy, on the stage. 
 
 Bushnell( David), A.M., of Saybrook, 
 in Connecticut, in 1776 invented 
 several machines for the annoyance 
 of shipping: he destroyed a vessel 
 in the charge of Commodore Sim- 
 monds, whose report to the Admi- 
 ralty was published. 
 
 Buss, a small sea-vessel used in the 
 herring fishery. 
 
 Bust, in sculpture, the head, neck, 
 and breast of human figure. 
 
 Bustum, anciently a tomb. 
 
 But, the end of a plank where it 
 unites with another. 
 
 73 
 
 But-hinges, those employed in the 
 hanging of doors,, shutters, etc, 
 
 Butmen cheeks, the two solid sides of 
 a mortise varying in thickness. 
 
 * Butments, the supports on which the 
 
 feet of arches stand. 
 
 Butterfly -valve, the double valve of 
 an air-pump bucket, consisting of 
 two clack-valves, having the joints 
 opposite and on each side of the 
 pump-rod. 
 
 Butteris, an instrument of steel set in 
 a wooden handle, used by farriers 
 for paring the hoof of a horse. 
 
 Butternut-wood is of large size, and 
 is produced in New Brunswick. 
 The propagation of this tree is very 
 easy, either from the cuttings or 
 from the nut. 
 
 Buttery, a cellar in which butts of 
 wine are kept ; aplace for provisions. 
 
 Buttock, the round part of a ship 
 abaft, from the wing transom to the 
 upper water-line, or lower down. 
 
 Button (in smithery), a brass knob of 
 a lock serving to open or shut a 
 door. 
 
 Button (in carpentry), a piece of wood 
 
 upon a nail, to keep a door close. 
 i/Buttress,\\\Goi}\\c architectural struc- 
 tures, a pilaster, pier, or masonry 
 added to and standing out from the 
 exterior of a wall. Buttresses are 
 usually divided into several heights, 
 each of which projects less from the 
 wall as they ascend. 
 y 'But tress, a piece of strong wall that 
 stands on the outside of another 
 wall, to support it. 
 
 By, said of a vessel when her head is 
 lower in the water than her stern ; 
 if her stern is lower in the water, 
 she is by the stern. 
 
 Byard, a piece of leather across the 
 breast, used by those who drag the 
 
 ., sledges in coal-pits. 
 
 * Byzantine Architecture. About the 
 
 year A.D. 828, Constantino, who 
 had previously resided at Rome, 
 commenced his new capital in the 
 East, which was called after his 
 name, and in May, 330, was so- 
 lemnly dedicated to the Virgin 
 Mary. He adorned it with so 
 
CAB 
 
 GABBLING. 
 
 CAB 
 
 many stately edifices that it nearly 
 equalled the ancient capital itself: 
 he here built a cathedral dedicated 
 to Santa Sophia, or the Eternal Wis- 
 dom, and a church to the Apostles. 
 This cathedral, having been twice 
 destroyed by fire, was finally rebuilt 
 about 532 A.B., by Justinian, who 
 had invited the celebrated architect 
 Anthemius to Constantinople for 
 that purpose. It was completed in 
 six years from the time of laying 
 the first stone. 
 
 The Emperor, in his admiration 
 of this magnificent edifice, is said to 
 have exclaimed, " I have vanquished 
 thee, Solomon :" and with justice 
 might he glorify himself, for the 
 dome of St. Sophia is the largest in 
 the world, and the more to be ad- 
 mired in its construction from the 
 lowness of the curvature. 
 
 This church, after twelve centu- 
 ries, remains the same, with the ex- 
 ception of the mode of worship to 
 which it is devoted. It still retains 
 its former name, but the Maho- 
 metans, instead of the Christians, 
 possess it. 
 
 This is the earliest Byzantine 
 building extant, totally dissimilar 
 in arrangement to the Christian 
 churches in the empire. 
 
 The plan of the interior is that of 
 a Greek cross, the four arms of 
 which are of equal length ; the cen- 
 tral part is a square, the sides are 
 about 115 feet in length. At each 
 angle of the square a massive pier 
 has been carried, 86 feet in height 
 from the pavement, and four semi- 
 circular arches stretch across the 
 
 intervals over the sides of thesquare, 
 and rest on the piers. The interior 
 angles between the four piers are 
 filled up in a concave form. At 
 145 feet from the ground is the level 
 of the springing of the dome, which 
 is 115 feet in diameter; the form 
 is a segment of a circle, and the 
 height is equal to one-sixth of its 
 diameter at the base. On both the 
 eastern and western side of the 
 square is a semicircular recess, with 
 domes that rest against the main 
 arches, and assist in resisting the 
 lateral thrust. On the north and 
 south sides of the square are vesti- 
 bules forming a square on the plan. 
 Above the vestibules are galleries 
 appropriated to women during the 
 performance of worship. The whole 
 church is surrounded by cloisters, 
 and enclosed by walls. 
 
 The total cost of St. Sophia has 
 been reckoned at the lowest com- 
 putation to have exceeded one mil- 
 lion pounds ; as before the building 
 was four feet out of the ground, its 
 cost had amounted to a sum equi- 
 valent to 200,000 sterling. 
 
 Besides this cathedral, Justinian 
 is said to have built, at Constanti- 
 nople, twenty-five churches to the 
 honour of Christ, the Virgin, and 
 the Saints ; he also built A church 
 to St. John at Ephesus, and another 
 to the Virgin at Jerusalem : the 
 bridges, hospitals, and aqueducts 
 erected by this emperor were nu- 
 merously distributed throughout 
 the empire. 
 Byzanteum artificium, mosaic-work. 
 
 c. 
 
 GABBLING. The process in the manu- 
 facture of iron, which in Glouces- 
 tershire is called ' scabbling,' or, 
 more correctly, ' cabbling,' may be 
 thus described. When the cast or 
 pig-iron has been subjected to the 
 influence of a refinery, the product 
 is called ' Finery :' it is then carried 
 
 74 
 
 to the forge, and smelted in a fur- 
 nace with charcoal: in a short time, 
 a large ball, about 2cwt.,is formed 
 by working with an iron bar ; this 
 ball is then taken to a large ham- 
 mer, and beaten into a flat oval or 
 oblong shape, from 2 to 4 inches 
 in thickness : this is allowed to 
 
CAB 
 
 CALCULATING MACHINES. 
 
 CAL 
 
 cool, when ' cabbling ' commences, j 
 which is simply breaking up this 
 flat iron into small pieces. Men 
 are especially allocated for this ope- 
 ration, and are named ' cabblers.' 
 The pieces of iron obtained by 
 cabbling are then heated in another 
 furnace almost to fusion, hammered 
 down into shape, and ultimately 
 drawn out into bar-iron. 
 
 Cabin, a room or apartment in a ship 
 where any of the officers usually re- 
 side, and also used in passenger ves- 
 sels for the residence of passengers. 
 
 Cabinet pictures, usually denominated 
 so, are small valuable paintings 
 from the old masters, painted on 
 copper, panel, or canvas. Modern 
 subjects, if painted small in size, 
 should equally be called Cabinet. 
 
 Cabinets, in Tudor times, were of 
 massive proportions, carved in oak, 
 ebony, walnut, and other woods, 
 inlaid. Some of them answered 
 the double purpose of depositories 
 and cupboards for plate, from 
 having drawers and recesses, or 
 ambries, enclosed by doors ; and 
 broad shelves between the tiers of 
 turned columns were conspicuous 
 objects in these apartments. 
 
 Cable, a thick stout rope, made of 
 
 > hemp, etc., to keep a ship at anchor. 
 
 Cable-moulding ,abead or torus mould- 
 ing, cut in imitation of the twisting 
 of a rope, much used in the later 
 period of the Norman style. 
 
 ^Cabling, a round moulding, frequently 
 used in the flutes of columns, pilas- 
 ters, etc. 
 
 Cadmia, a stone, out of which brass 
 is tried ; brass ore. 
 
 Caduceus, an emblem or attribute of 
 Mercury : a rod entwined by two 
 winged serpents. 
 
 Calatura (Greek), a branch of the 
 fine arts, under which all sorts of or- 
 namental work in metal, except ac- 
 tual statues, appear to be included. 
 
 Caementicius, built of unhewn stones ; 
 large irregular masses laid together 
 without mortar, having the inter- 
 stices filled in with small chippings. 
 
 Caen stone, a peculiar quality of stone 
 
 used for building purposes, prin- 
 cipally for Gothic structures ; it is 
 taken from quarries in Normandy. 
 
 Cayework, the uppermost carved work 
 of the hull of a ship. 
 
 Caisson, a wooden frame or box with 
 a flat bottom, made of strong 
 timbers firmly connected together ; 
 "used for laying the foundations of 
 a bridge in situations where the 
 coffer-dam cannot be adopted. 
 
 Caisson, a name given to the sunk 
 panels of various geometrical forms 
 symmetrically disposed in flat or 
 vaulted ceilings, or in soffits gene- 
 rally. 
 
 Cal, in Cornish mining, a kind of iron 
 Gossan stone found in the bryle and 
 backs of lodes, much of the colour 
 of old iron ; reckoned a poor brood 
 with tin. 
 
 Calcar, a small oven or reverberatory 
 furnace, in which the first calcina- 
 tion of sand and potashes is made 
 for turning them into frit, from 
 which glass is ultimately made. 
 
 Calcareous earth, the same as lime, 
 and of which there are various 
 combinations, as marble, limestone, 
 marl, gypsum, etc. 
 
 Calcatorium, among the Romans, a 
 raised platform of masonry in the 
 cellar attached to a vineyard. 
 
 Calcination, the process of subjecting 
 a body to the action of fire, to drive 
 off the volatile parts, whereby it is 
 reduced to a condition that it may 
 be converted into a powder : thus 
 marble is converted into lime by 
 driving off the carbonic acid and 
 water ; and gypsum, alum, borax, 
 and other saline bodies are said to 
 be calcined when they are deprived 
 of their water of crystallization. 
 
 Calcium, the metallic basis of lime. 
 
 Calcography, writing, engraving, etc. 
 
 Calculating machines are of early in- 
 vention ; but recently Mr. Babbage 
 has completed a calculating ma- 
 chine surpassing all previous ones ; 
 the machine accomplishes the ad- 
 ditions of numbers by the move- 
 ments of a number of cylinders 
 having on the convex surface of 
 
CAL 
 
 CALORIC SHIP. 
 
 CAL 
 
 each the series of numbers 1234 
 5678 90; and the operations 
 are of two kinds : by the first the 
 additions are made, and by the 
 second there is introduced the 1, 
 which should be carried to the 
 ten's place every time that the sum 
 of the two numbers is greater than 
 10, etc. 
 
 Caldarium, the hot bath. The vase 
 which supplied the hot bath was 
 likewise so termed. According to 
 Vitruvius, the thermal chamber in 
 a set of baths. 
 
 Calender, a mechanical engine for 
 dressing and finishing cloths. 
 
 Calends, in Roman antiquity, the first 
 day of every month. 
 
 Caliber or Caliper compasses ; com- 
 passes made with bowed or arched 
 legs, for the purpose of taking the 
 diameter of any round body. 
 
 Caliber, an instrument used by car- 
 penters, joiners, and bricklayers, to 
 see whether their work be well 
 squared. 
 
 Calico, a cloth made from cotton- 
 wool, like linens : the origin of the 
 name is from Calicut, in India. 
 
 Calico-printing, the art of applying 
 coloured patterns on a white or 
 coloured ground of linen or cotton. 
 
 Calidnets, pipes or canals disposed 
 along the walls of houses and 
 apartments ; used by the ancients 
 for conveying heat to several re- 
 mote parts of the house. 
 
 Caligraphy, fair or good writing. 
 
 Calin, a mineral, like lead and tin. 
 
 Calk, a Cornish term for lime. 
 
 Callipers, a species of compasses with 
 legs of a circular form, used to take 
 the thickness or diameter of work, 
 either circular or flat ; used also to 
 take the interior size of holes. 
 
 Callipers, in turning, compasses with 
 each of the legs bent into the form 
 of a curve, so that when shut the 
 points are united ; and the curves, 
 being equal and opposite, enclose a 
 space. The use of the callipers is 
 to try the work in the act of turn- 
 ing, in order to ascertain the dia- 
 meter or the diameters of the 
 
 various parts. As the points stand 
 nearer together at the greatest 
 required diameter than the parts 
 of the legs above, the callipers are 
 well adapted to the use intended. 
 
 Callys or jR/&zs(Cornish),hard, smart ; 
 the most common and agreeable 
 stratum in our mine country, 
 usually called killas. 
 
 Caloric, the matter and cause of heat. 
 
 Caloric (Ericsson's) ship has under- 
 gone a great experiment in naviga- 
 tion. Wise men have long pondered 
 the idea which Captain Ericsson is 
 working out patiently and hope- 
 fully. The need of new motors has 
 become more manifest with the 
 advance of time and commercial 
 prosperity. Electricity has been 
 tried, and has not succeeded. Ca- 
 loric was something never known 
 in its best sense until now, and the 
 credit is due to Captain Ericsson 
 of directing attention to an old 
 agent of which new applications 
 may produce the most remark- 
 able results. The experiment now 
 making is no ephemeral fancy, but 
 is the work of a quarter of a century 
 of mature reflection and diligent 
 inquiry. The ingenious projector 
 under whose auspices it is carried 
 forward has devoted his best ener- 
 gies to the task, and it will not 
 fail through want of forecast, judg- 
 ment, or ability. 
 
 Calorific, in chemistry, the quality of 
 producing heat. 
 
 Calorimeter, an instrument to measure 
 the heat given out by a body in 
 cooling by the quantity of ice it 
 melts. 
 
 Calotte, a round cavity or depressure 
 in form of a cap or cup. 
 
 Calquing, the process of copying or 
 transferring a drawing. It is ef- 
 fected by rubbing over the back of 
 the original with a fine powder of 
 red chalk or black lead; the smeared 
 side is then laid on a sheet of paper, 
 and the lines of the drawing are 
 traced by a blunt-pointed needle, 
 which imprints them on the paper 
 underneath. Another method is to 
 
CAL 
 
 CAMBER-SLIP. 
 
 CAM 
 
 hold the drawing up to a window 
 with a sheet of paper before it : 
 the outlines will appear through, 
 and may he penciled off without 
 damage to the original. 
 
 Calyon, flint or pehble stone, used in 
 building walls, etc. 
 
 Cam, in steam machinery, a plate with 
 curved sides, triangular or other- 
 wise, fixed upon a revolving shaft, 
 for changing the uniform rotatory 
 motion into an irregular rectilinear 
 motion. It is sometimes used for 
 moving the slide-valves. 
 
 Camaieu,3iierm used in painting when 
 there is only one colour, the light 
 and shades being of gold, or on a 
 golden and azure ground. It is 
 chiefly used to represent basso- 
 rilievo. 
 
 Camber, the convexity of a beam upon 
 the upper surface, in order that it 
 may not become concave by its own 
 weight, or by the binder it may have 
 to sustain, in the course of time. 
 
 Camber-beams, are those used in the 
 flats of truncated roofs, and raised 
 in the middle with an obtuse angle, 
 for discharging the rain-water to- 
 wards both sides of the roof. 
 
 Camber-slip, a piece of wood, gene- 
 rally about half an inch thick, with 
 at least one curved edge rising 
 about 1 inch in 6 feet, for drawing 
 the soffit-lines of straight arches : 
 when the other edge is curved, it 
 rises only to about one-half of the 
 other, viz. about half an inch in 6 
 feet, for the purpose of drawing the 
 upper side of the arch so as to pre- 
 vent it from becoming hollow by 
 the settling of the bricks. The 
 upper edge of the arch is not always 
 cambered, some persons preferring 
 it to be straight. The bricklayer 
 is always provided with a camber- 
 slip, which, being sufficiently long, 
 answers to many different widths 
 of openings : when he has done 
 drawing his arch, he gives the 
 camber-slip to the carpenter, in 
 order to form the centre to the 
 required curve of the soffit. 
 
 Cambering, a sea phrase, used when 
 
 a deck is higher in the middle than 
 at the ends. 
 
 Camel, the name of a machine used 
 by the Dutch for carrying vessels 
 heavily laden over the sand-banks 
 in the Zuyder Zee. 
 
 Camera (Greek), an arched or vaulted 
 roof, covering, or ceiling, formed by 
 circular bands or beams of wood, 
 over the intervals of which a coating 
 of lath and plaster was spread: 
 they resembled, in their construc- 
 tion, the hooped awnings now 
 commonly in use. 
 
 Camera-lucida, and Camera-obscura, 
 (the light and dark chamber,) the 
 names given to two methods, simi- 
 lar in principle, of throwing images 
 of external objects upon plane or 
 curved surfaces, for the purpose of 
 drawing or amusement : in the first 
 contrivance there is no chamber; 
 but as it was the last invented, and 
 as its predecessor had been called 
 the 'camera-obscura,' it was termed 
 the ' camera-lucida.' 
 
 Camerated, a term applied to the roof 
 of a church. 
 
 Cameron (C.), architect ; published in 
 1772 and 1775, editions of the 
 work on the Baths of the Romans. 
 
 Games, the slender rods of metal used 
 by glaziers as turned lead; they 
 are usually cast in lengths which 
 measure 12 or 14 inches. 
 
 Caminus, according to Pliny, a smelt- 
 ing furnace. 
 
 Campance or Campanulce or Guttce, 
 the drops of the Doric architrave. 
 
 Campanile, from the Italian, a bell- 
 tower, principally used for church 
 purposes, but now sometimes for 
 domestic edifices. 
 
 Campanini, a species of marble taken 
 out of the mountain of Carrara, in 
 Tuscany ; so called because, when 
 wrought, it imitates the sound of 
 a bell. 
 
 Campanologia, the art or science of 
 ringing of bells. 
 
 Campbell (C.), an architect of his 
 period of some celebrity ; erected 
 several of the large mansions of 
 the nobility and gentry of this 
 
CAM 
 
 CANAL NAVIGATION. 
 
 CAN 
 
 country, and first published hig 
 great work, entitled ' Vitruvius 
 Britannicus,' in 1715. 
 
 Camphor-wood is imported from Chi- 
 na and the Indies in logs and planks 
 of large size, and used in England 
 for cabinet-work and turnery. 
 
 Campus Martins, a district outside 
 the walls of ancient Rome, between 
 the Quirinal and Pincian Mounts 
 and the Tiber, dedicated to Mars : 
 there public exercises were per- 
 formed, and the consuls and other 
 magistrates elected : it was adorned 
 with statues, columns, arches, etc., 
 and much frequented by the citizens. 
 
 Camus de Mezieres (M. le), born at 
 Paris in 1721, and died in 1789 : 
 he was the architect of the Halle 
 au Ble and other buildings, and the 
 author of several valuable profes- 
 sional works. 
 
 Cam-wood, the best and hardest of 
 the red dye-woods : it is brought, 
 from Africa, and used in ornamental 
 and eccentric turnery. 
 
 Can, a term used in Scotland for a 
 chimney-pot. 
 
 Canal of the larmier, in architecture, 
 the hollowed plafond or soffit of a 
 cornice, which makes the pendent 
 mouchette. 
 
 Canal of the volute, in the Ionic 
 capital, is the face of the circum- 
 volutions enclosed by a listel. 
 
 Canal Navigation, or river and inland 
 navigation, or internal communi- 
 cation by water, terms severally 
 expressed. The origin of inland 
 navigation is involved in great ob- 
 scurity. The ancient inhabitants of 
 every part of the globe wherewith 
 history has made us acquainted, 
 were alive to the benefits resulting 
 from the adoption of inland navi- 
 gation: in England, the first on 
 record is the Caerdike, cut by the 
 Romans. Subsequently, very many 
 very important ones, particularly 
 those by Brindlay, under the direc- 
 tion of the celebrated Duke of 
 Bridgewater ; and as late as 1829, 
 the science of canal engineering 
 was in active operation. Canals in 
 
 France for ' grande navigation' are 
 made 33 feet 4 inches wide upon 
 the floor-line, and 49 feet 6 inches 
 upon the water-line, by 5 feet 5 
 inches depth of water. The locks 
 are 106 feet 8 inches long by about 
 17 feet wide ; the towing-paths 
 13 feet wide. Canals for 'petite 
 navigation ' are made only 33 feet 
 4 inches wide upon the water-line, 
 and 22 feet on the floor, with a 
 depth of water of 5 feet. The locks 
 are 100 feet long by 9 feet 1 inch 
 wide. Some of theFrench canals for 
 steam navigation have locks from 
 26 to 40 feet wide, and of lengths 
 between 150 and 233 feet in clear 
 of gates. In England, no very 
 definite rule appears to be followed 
 in fixing the dimensions of canals. 
 Those executed for the internal 
 important lines vary from 31 to 48 
 feet upon the water-line, with an 
 average depth of about 5 feet. The 
 locks are generally 70 feet in length 
 by 14 feet 6 inches to 18 feet wide. 
 Small canals, in the mining dis- 
 tricts, have in some cases been 
 executed with a width of not more 
 than 16 feet on the water-line, and 
 they range from that to 28 feet. 
 The locks are made of the same 
 length as for large canals, but of 
 only half the width. Ship-canals 
 have been made of ihuch larger 
 dimensions, such as the Caledonian 
 Canal, which has in part 122 feet 
 upon the water-line, with a depth 
 of 20 feet. The Gloucester and 
 Berkeley Canal has a water-line of 
 70 feet and a depth of 18 feet. 
 The Thames and Medway had a 
 width of 50 feet by a depth of 7 
 feet ; the Ulverstone, 65 feet by 15 
 feet : the locks being in proportion 
 to the size of the canals. In the 
 United States the same irregularity 
 occurs in the dimensions of canals 
 as in our own country. 
 
 Canal, an artificial watercourse for 
 connecting rivers and lakes ; a 
 navigable communication. 
 
 Canalis, in Latin, a water-pipe or 
 gutter ; used in architecture for any 
 
CAN 
 
 CANDLESTICKS. 
 
 CAN 
 
 channel, such as the flutings of 
 columns ; the channel between the 
 volutes of an Ionic column. 
 
 Canary-wood, from South America, 
 is a sound, light, orange-coloured 
 wood, used for cabinet-work, mus- 
 ketry, and turnery. 
 
 Cancelli, among the Romans, iron 
 gratings and trellis-work ; in mo- 
 dern buildings, latticed windows 
 made with cross-bars of wood, iron, 
 lead, etc. 
 
 Candela, a candle, made either of 
 wax or tallow ; used generally by 
 the Romans before the invention 
 of lamps. 
 
 Candelabrum, originally a candlestick, 
 but afterwards used to support 
 lamps. 
 
 Candlemas, the popular name for the 
 feast of the Purification of the 
 Virgin Mary, February 2, derived 
 from the lights which were then 
 distributed and carried about in 
 procession. 
 
 Candlestick of gold ( The} was made 
 by Moses for the service of the 
 Temple, and consisted wholly of 
 pure gold : it had seven branches, 
 upon the extremities of which were 
 seven gold lamps, which were 
 fed with pure olive oil, and lighted 
 every evening by the priest on 
 duty : it was used in the holy place, 
 and served to illumine the altar of 
 incense and the table of shew- 
 bread, which stood in the same 
 chamber. 
 
 Candlesticks. The magnificence of 
 these articles was at first displayed 
 in chapels and in domestic apart- 
 ments, as banquets in early times 
 were given by daylight. We find 
 them, however, of very costly de- 
 scriptions. In Henry the Eighth's 
 temporary banqueting - room, at 
 Greenwich, the " candlestykes were 
 of antyke worke, which bare little 
 torchetts of white waxe : these 
 candlestykes were polished lyke 
 ambre." 
 
 Canyica-wood, from South America, is 
 of a light and yellow-brown colour, 
 used for cabinet-work and turnery. 
 
 79 
 
 Can-hooks, strings with flat hooks at 
 each end, used for hoisting barrels 
 or light casks. 
 
 Canopy, a covering or hood, the en- 
 riched projecting head to a niche 
 or tabernacle. The tablet or drip- 
 stone, whether straight or circular, 
 over the heads of doors or windows, 
 if enriched, is so called. 
 ^Canopy, in Gothic architecture, an 
 ornamental projection over doors, 
 windows, etc. ; a covering over 
 niches, tombs, etc. 
 
 Cant, a term used among carpenters 
 to express the cutting off the angle 
 of a square. 
 
 Canted, applied to a pillar or turret 
 when the plan is of a polygonal 
 form. 
 
 Canterbury (John), born at Tewks- 
 bury, was clerk of the works of 
 King's College Chapel, Cambridge, 
 of which College he was a Fellow 
 in 1451. 
 
 Canterbury (Michael of), erected in 
 1291-93, the Cross in Westcheap, 
 London, which was the handsomest, 
 except Charing, of all that were 
 erected to the memory of Queen 
 Eleanor. 
 
 Canterii, beams of wood in the frame- 
 work of a roof, extending from the 
 ridge to the eaves, corresponding 
 to the rafters of a modern roof. 
 The word canterii was also applied 
 to two inclining reeds fixed in the 
 ground some distance asunder and 
 meeting at the top, for the support 
 of vines. 
 
 Cantharus, a fountain or cistern in 
 the atrium or court-yard before 
 ancient churches, at which persons 
 washed before they entered the 
 sacred buildings. 
 
 Canthus, in Greek and Latin, the 
 tire of a wheel ; a hoop of iron 
 or bronze fastened on to the felloe, 
 to preserve the wood from abra- 
 sion. 
 
 Cantilevers are horizontal rows of 
 timbers, projecting at right angles 
 from the naked part of a wall, for. 
 sustaining the eaves or othermould- 
 ings. 
 
CAN 
 
 CAPITAL. 
 
 CAP 
 
 Cantling. The lower of two courses 
 of burnt bricks, which are placet 
 on the top of a clamp before fire is 
 applied. 
 
 Cant -moulding, a bevelled surface, 
 neither perpendicular to the horizon 
 nor to the vertical surface to which 
 it may be attached. 
 
 Cantoned, in architecture, is when the 
 corner of a building is adorned 
 with a pilaster, an angular column, 
 rustic quoins, or anything that 
 projects beyond the wall. 
 
 Cant-pieces, in ships, pieces of timber 
 fastened to the angles of fishes and 
 side-trees, to supply any part that 
 may prove rotten. 
 
 Cant-timbers, in ship-building, those 
 timbers or ribs of the ship which 
 are situated afore or abaft, or at the 
 two ends, where the ship grows 
 narrower below. 
 
 Cant-timber abaft, the chock upon 
 which the spanker-boom rests when 
 the sail is not set. 
 
 Cantuar. The signature of the Arch- 
 bishop of Canterbury, is thus 
 abbreviated, the Christian name 
 being usually prefixed. 
 
 Canvas, the cloth of which the sails 
 of ships are made. 
 
 Caoutchouc, a substance produced by 
 the siphonia elastica, the ficus elas- 
 ti'.a, and the urceola elastica, and 
 many other American and Asiatic 
 trees. It is often termed Indian- 
 rubber, from its use in removing 
 pencil traces from paper. There are 
 various chemical properties which 
 render caoutchouc valuable in the 
 arts, but elasticity and impervious- 
 ness to water are those for which 
 it is most prized. It is worked into 
 a great variety of useful things for 
 dress and for domestic purposes. 
 
 Cap, a thick, strong block of wood, 
 with two holes through it, one 
 square and the other round, used in 
 ship-building to confine together 
 the head of a mast and the lower 
 part of that next above it. 
 
 Capacity, the same in sense as content 
 or volume in pure mathematics. 
 In physics it generally signifies the 
 
 80 
 
 power of holding or retaining : thus 
 we speak of the capacity of a body 
 for heat, etc. 
 
 Capel, in mining, a stone composed of 
 quartz, schorl, and hornblende, 
 usually occurring in one or both 
 walls of a lode, and more frequently 
 accompanying tin than copper ores. 
 
 Capillary attraction and repulsion. 
 These names have been given to the 
 properties of matter which cause 
 the ascent above or descent below 
 the level of the surrounding fluid 
 which takes place when a tube of 
 small diameter is dipped into water, I 
 mercury, etc. 
 
 "Capital, in architecture, the head or 
 uppermost part of a column or pi- 
 laster. The capitals of the columns 
 constitute the principal and most 
 obvious indicia! mark of the re- 
 spective orders. For those of each 
 of the three classes or orders a cer- 
 tain character conformable with the 
 rest of the order is to be observed ; 
 but that attended to, further re- 
 striction is unnecessary. Between 
 several examples, all decidedly re- 
 ferable to one and the same order, 
 very great special differences occur, 
 and there might easily be a very 
 great many more. Although the 
 capital itself is indispensable, it is 
 so only aesthetically, and not out of 
 positive necessity. The necessity is 
 only artistic: decoration of the kind 
 there must be, but the express 
 mode of it is one of those matters 
 which should be left to design, to 
 which it properly belongs. Capitals 
 are just as legitimate subjects for 
 the exercise of taste and invention 
 as anything else in decorative de- 
 sign. The capital is only an orna- 
 mental head to the column, and 
 therefore admits of being as freely 
 designed as any other piece of orna- 
 ment, on the conditions of its being 
 accordant in character with the 
 rest of the order, and of forming an 
 agreeable transition from the shaft 
 of the column to the architrave. 
 
 Capitolium, a temple or citadel at 
 Home, on the Tarpeian rock : it was 
 
CAP 
 
 CARAVANSERAI. 
 
 CAR 
 
 finished by Tarquinius Superbus, 
 and consecrated by the consul M. 
 Horatius, was burnt in the time 
 of Marius, and rebuilt by Sylla, 
 destroyed a second and a third time 
 in the troubles under Vitellius and 
 Vespasian, and lastly raised again 
 by Domitian. Its name was derived 
 from the discovery of the head of 
 Tolius, during the excavation of 
 the earth for the foundation. Q. 
 Catulus consecrated it to Jupiter 
 Capitolinus, and covered it with 
 gilded brass tiles. The steep ascent 
 of the rock was mounted by 100 
 steps on the side of the forum. In 
 the temple were statues of gold and 
 silver, vessels of those metals and 
 of crystal, and 3000 brass tables, 
 on which the Roman laws were 
 engraved. 
 
 Caple (in Cornwall) stone is some- 
 thing like limestone, but will not 
 burn. The walls of most lodes 
 are of this kind, and therefore it is 
 common to call a lode by the name 
 of its caple : those veins which 
 abound with it are termed caples 
 or caple-lodes. 
 
 Capreoli, the pieces of timber on a 
 roof which serve to uphold the 
 axes or principals. A fork inclined 
 so as to afford support to anything 
 was formerly called a Capreolus. 
 
 Capsa or Capsula, a box for holding 
 books among the Romans : these 
 boxes were usually made of beech 
 wood, and were cylindrical in form. 
 
 Capsize, to overturn. 
 
 Capstan, in naval architecture, a 
 strong massive piece of timber let 
 down through the decks of a ship, 
 and resting its foot or axis, which 
 is shod with iron, in an iron socket, 
 called a saucer, fixed on a wooden 
 block or standard, called the step, 
 resting on the beams. 
 
 Captain, in mining, an experienced 
 miner ; one who directs and over- 
 sees the workmen and business of 
 a mine. 
 
 Caracol, a term sometimes used for a 
 staircase in a helix or spiral form. 
 
 Caradoc formation, the uppermost of 
 
 the two great divisions of the lower 
 Silurian strata of Murchison, seen 
 principally in Shropshire, Worces- 
 tershire, Somersetshire, etc., and on 
 the eastern borders of Wales. 
 
 Caravanserai, a building in the East, 
 expressed in our version of the 
 Scripture by the term Inn ; in 
 Turkey it is understood to be 
 a place of accommodation, for 
 strangers and travellers : they are 
 built at proper distances through 
 the roads of the Turkish dominions, 
 and afford the indigent and weary 
 traveller an asylum from the in- 
 clemency of the weather. 
 
 Carbon, a non-metallic elementary 
 solid body, which is widely diffused 
 throughout nature. The purest and 
 at the same time the rarest formed 
 which it occurs is that of the dia- 
 mond ; the more common states in 
 which it is met with are those of 
 anthracite, graphite, and coal : an- 
 other form is that of charcoal. 
 
 Carbonate, a salt composed of car- 
 bonic acid and a base. The chief 
 varieties are described under their 
 alkaline, earthy, and metallic bases. 
 
 Carburet, a compound of carbon with 
 nitrogen, metals, etc. 
 
 Carcase (The) of a building is the 
 naked walls and the rough timber- 
 work of the flooring and quarter 
 partitions, before the building is 
 plastered or the floors laid. 
 
 Carcase-roofing, that which supports 
 the covering by a grated frame of 
 timber-work. 
 
 Career, a prison or gaol. The Roman 
 prisons were divided into three 
 stories, one above the other, each 
 of which was appropriated to dis- 
 tinct purposes. 
 
 Card-making machine, an arrange- 
 ment of wires used in the cotton 
 manufacture, for disentangling the 
 fibres of cotton preparatory to 
 spinning. 
 
 Cardo, a pivot and socket, an appa- 
 ratus by means of which the doors 
 of the ancients were fixed in their 
 places, and made to revolve in 
 opening and shutting. 
 
 81 
 
 E3 
 
CAR 
 
 CARLISLE TABLES. 
 
 CAR 
 
 Careening, the operation of heaving 
 a ship down on one side by the 
 application of a strong purchase to 
 her masts, which are properly sup- 
 ported for the occasion to prevent 
 their breaking with so great a 
 strain, and by which means, one 
 side of the bottom being elevated 
 above the surface of the water, it 
 may be cleansed or repaired. 
 Carina, according to Cicero, the keel 
 or lowest piece of timber in the 
 framework of a ship. 
 Cartings, short pieces of timber rang- 
 ing fore and aft from one deck- 
 beam to another, into which their 
 ends are mortised : they are used 
 to sustain and fortify the smaller 
 beams of the ship. 
 Carlisle Tables, so called from the 
 more recent mode of making cal- 
 culations of the value of annuities 
 on lives, based on the average du- 
 ration of human life, as taken at 
 Carlisle, in Cumberland. The value 
 of a life annuity depends upon the 
 manner in which it is presumed a 
 large number of persons, similarly 
 situated with the buyer, would die 
 off successively. Various tables of 
 these decrements of life, as they 
 are called, have been constructed 
 from observations made among 
 different classes of lives. Some 
 make the mortality greater than 
 others ; and, of course, tables which 
 give a large mortality, give the 
 value of the annuity smaller than 
 those which suppose men to live 
 longer. Those who buy annuities 
 would therefore be glad to be rated 
 according to tables of high mor- 
 tality, or low expectation of life ; 
 while those who sell them would 
 prefer receiving the price indicated 
 by tables which give a lower rate 
 oif mortality. Hence arise bar- 
 gains or stipulations according to 
 either the Northampton or Carlisle 
 tabulated rating of the duration of 
 life. In assurances the reverse is 
 the case : the shorter the time 
 which a man is supposed to live, 
 the more must he pay the office, 
 
 82 
 
 that the latter may at his death 
 have accumulated wherewithal to 
 pay the amount. The Northamp- 
 ton tables, formed by Dr. Price, 
 from observations of burials at 
 Northampton, as compared with 
 all other tables of authority, give 
 too high a mortality at all the 
 younger and middle ages of life, 
 and, consequently, too low a value 
 of the annuity. The Carlisle tables, 
 formed by Mr. Milne, give much 
 less mortality than most of the 
 old tables, and therefore a higher 
 value of the annuities : they have 
 been proved to represent the actual 
 state of life among the middle 
 classes. 
 
 Carlovingian Architecture. French 
 authors establish two epochs of art, 
 under the terms Merovingian (from 
 Clovis toPepin, 481-751) and Car- 
 lovingian (from Pepin to Hugh 
 Capet, 751-987). 
 
 Carmine (colour], a name originally 
 given only to fine specimens of the 
 tinctures of kermes and cochineal, 
 and denoting generally at present 
 any pigment which resembles them 
 in beauty, richness of colour, and 
 fineness of texture : hence we hear 
 of blue and other coloured car- 
 mines, though the term is princi- 
 pally confined to the crimson and 
 scarlet colours produced from co- 
 chineal by the agency of tin. 
 
 Cam, in Cornish mining, a rock ; a 
 heap of rocks ; a high rock. 
 
 Carnagioni (of the Italians), a colour 
 which differs from terra puzzuoli 
 in its hue ; in which respect, other 
 variations and denominations are 
 produced by dressing and com- 
 pounding. 
 
 Carol, a small closet or enclosure to 
 sit and read in. 
 
 Carpenter's square : the stock and 
 blade are formed, in one piece, of 
 plate-iron, and the instrument is 
 thus constructed : one leg is 18 
 inches in length, numbered from 
 the exterior angle ; the bottoms of 
 the figures are adjacent to the in- 
 terior edge of the square, and con- 
 
CAR 
 
 CARPENTRY. 
 
 CAR 
 
 sequently their tops to the exterior 
 edge : the other leg is 12 inches in 
 length, and numbered from the 
 extremity towards the angle ; the 
 figures are read from the internal 
 angle, as in the other side; and 
 each of the legs is about an inch 
 broad. It is not only used as a 
 square, but also as a level, and as a 
 rule : its application as a square 
 and as a rule is so easy as not to 
 require any example ; but its use 
 as a level, in taking angles, may be 
 thus illustrated : suppose it were 
 required to take the angle which 
 the heel of a rafter makes with the 
 back, apply the end of the short 
 leg of the square to the heel-point 
 of the rafter, and the edge of the 
 square level across the plate ; ex- 
 tend a line from the ridge to the 
 heel-point, and where this line cuts 
 the perpendicular leg of the square, 
 mark the inches : this will show 
 how far it deviates from the square 
 in 12 inches. 
 
 Carpenter's took : the principal tools 
 used in the rougher operations of 
 carpentry are the axe, the adze, 
 the chisel, the saw, the mortise 
 and tenon-gauge, the square, the 
 plumb-rule, the level, the auger, 
 the crow, and the draw-bore-pin, 
 or hook-pin, for draw-boring. 
 
 Carpentry is the art of combining 
 pieces of timber for the support 
 of any considerable weight or pres- 
 sure. 
 
 The theory of carpentrv is 
 founded on two distinct branches 
 of mechanical science : the one in- 
 forms us how strains are propagated 
 through a system of framing; the 
 other, how to proportion the re- 
 sistance of its parts, so that all may 
 be sufficiently strong to resist the 
 strains to which they are exposed. 
 The one determines the stability 
 of position, the other the stability 
 of resistance. Each of these may 
 be considered in the most simple 
 manner the subject admits of, with 
 the addition of rules and practical 
 remarks. 
 
 Timber is wrought into various 
 forms according to the principles 
 of geometry ; and these forms are 
 to be preserved in their original 
 shape only by adjusting the stress 
 and strain according to the laws of 
 mechanics. Hence the importance 
 of studying both these sciences 
 is evident, and particularly the 
 latter ; for unless the stress and 
 strain be accurately adjusted, the 
 most careful attention to geometri- 
 cal rules, and the most skilful work- 
 manship, will be exerted in vain. 
 If, for instance, the centre of ah 
 arch were to be drawn and worked 
 ever so truly to the curve required, 
 what would it avail if the centre 
 changed its form with every course 
 of stone laid upon it ? And it must 
 be remarked, that this is not an 
 imaginary case, but one that has 
 frequently happened ; and not only 
 to men ignorant of mechanics, but 
 to some of the most celebrated 
 engineers that France ever pro- 
 duced. 
 
 The engineers of our own coun- 
 try have been more successful, 
 having succeeded in gradually in- 
 troducing a better principle of con- 
 structing centres than our neigh- 
 bours. The greatest defect of the 
 English centres is now an excess 
 of strength, which, on principles of 
 economy, it would be desirable to 
 avoid in erections for temporary 
 purposes. 
 
 Carpentry, in civil architecture, is 
 the art of employing timber in the 
 construction of buildings. 
 
 The first operation of dividing a 
 piece of timber into scantlings, or 
 boards, by means of the pit-saw, 
 belongs to sawing, and is previous 
 to anything done in carpentry. 
 
 The tools employed by the 
 carpenter are a ripping-saw, a 
 hand-saw, an axe, an adze, a 
 socket-chisel, a firmer-chisel, a rip- 
 ping chisel, an auger, a gimlet, a 
 hammer, a mallet, a pair of pincers, 
 and sometimes planes ; but as these 
 are not necessarily used, they are 
 
CAR 
 
 CARVING. 
 
 CAR 
 
 described under the head of joi- 
 nery, in which they are absolutely 
 necessary. 
 
 Carr (John), born 1723, at Horbury, 
 near Wakefield, in Yorkshire, com- 
 menced his career as a working 
 mason; afterwards settling in York 
 as an architect, in 1750, he executed 
 many fine and expensive buildings ; 
 died in 1807. 
 
 Carrara marble, a species of white 
 marble : it is distinguished from 
 the Parian or statuary marble by 
 being harder and less bright. It 
 takes its name from Carrara, in 
 Italy. 
 
 Carrel, a pew, closet, or desk, with a 
 seat placed under a window, where 
 the monks were engaged in copying 
 writings. 
 
 Carriage of a stair, the timber which 
 supports the steps. 
 
 Carriclc-bend, a kind of knot. Car- 
 rick-bitts are the windlass-bitts. 
 
 Carrier, the piece of iron which is 
 fixed by a set-screw on the end of 
 a shaft or spindle to be turned in 
 a lathe, to carry it round by the 
 action of the driver of the centre 
 chuck. 
 
 Carry away, a sea-term, to break a 
 spar or part a rope. 
 
 Carthusian buildings, Charter-house. 
 The characteristic features of 
 these buildings are austere, and to 
 the Benedictine rule. The monas- 
 teries of this order had generally 
 two courts : the smaller, next the 
 entrance, contained the priorial 
 residence and the buildings allot- 
 ted to secular purposes. Females 
 were not only excluded from the 
 court, but from the church. 
 
 Cartoon, a distemper-coloured draw- 
 ing, made on paper, linen, parch- 
 ment, etc., of the exact pattern of 
 a design intended to be executed 
 either in tapestry, mosaics, or on 
 glass : such are Raphael's divine 
 pictures in Hampton Court Pa- 
 lace. 
 
 Cartoon, in painting, a design drawn 
 on strong paper, sometimes after- 
 wards calqued through, and trans- 
 
 84 
 
 ferred on the fresh plaster of a 
 wall, to be painted in fresco. 
 
 Cartouche, the same as modillion, 
 except that it is exclusively used 
 to signify the blocks or modillions 
 on the eaves of a house. 
 
 Cartouche, an ornament representing 
 a scroll of paper. 
 
 Carucru, or Chica, a new pigment, 
 of a soft powdery texture and rich 
 morone colour, first brought from 
 South America by Lieut. Mawe. 
 
 Carving and inlaying of woods had 
 become pretty general at the latter 
 end of the sixteenth century. " At 
 Hardwick, in Derbyshire (1570), 
 the wood-work, in several of the 
 principal apartments, is oak, inlaid 
 with ebony ornaments on the 
 panels and stiles. The doors and 
 shutters of ' Mary Queen of Scot's 
 room,' as it is called, are framed 
 in panels of light wood, inlaid 
 with profiles of the Caesars, and 
 other enrichments ; the stiles, of 
 darker coloured oak. In the state- 
 room, the walls are divided, at 
 about half the height, by a string- 
 ing, the upper part filled with 
 landscapes, figures, and animals, 
 relieved in plaster, and painted in 
 their proper colours on white 
 ground ; and the lower division 
 hung with tapestry. The chimney 
 front is entirely occupied by a 
 large armorial compartment, re- 
 lieved in plaster and emblazoned." 
 
 Caryates or Caryatides (Greek), fi- 
 gures used instead of columns, 
 employed in architecture to repre- 
 sent the portraiture of the defeated 
 Persians after the subjugation of 
 the Caryatae. The male figures are j 
 denominated Persians, Telamones, 
 or Atlantides ; the female, Caryans 
 or Caryatides. 
 
 1 'Caryatides, anthropostylar pillars or 
 human figures (usually female ones) 
 employed instead of columns to 
 support an entablature. Such fi- 
 gures ought always to be perfectly 
 free from all attitudinizing, and to 
 appear to support their burden 
 without any effort. Some very 
 
CAS 
 
 CASTING. 
 
 CAS 
 
 matter-of-fact critics object to ca- 
 ryatides as being at the best only 
 beautiful absurdities ; as if statues 
 so applied were particularly liable 
 to be mistaken for living persons 
 subjected to a more severe punish- 
 ment than that of being posted up 
 in a niche, or on the top of a 
 building. 
 
 Casa, according to Vitruvius, a cot- 
 tage ; a small country-house. 
 
 Cased tin, in Cornish mining, that 
 which is re-framed by the gentlest 
 current of water, and prevented 
 from running off the frame by turf 
 placed at the bottom. 
 
 Case-hardening. The hardness and 
 polish of steel may be united, in a 
 certain degree, with the firmness 
 and cheapness of malleable iron, 
 by what is called case-hardening, 
 an operation much practised and 
 of considerable use. 
 
 Casement, a frame enclosing part of 
 the glazing of a window, with 
 hinges to open and shut ; also an 
 early English name for a deep 
 hollow moulding. 
 
 'Casement, the same as ' scotia,' the 
 name of a hollowed moulding. 
 
 Casements, sashes or glass frames 
 opening on hinges and revolving 
 upon one of the vertical edges. 
 
 Cases, in Cornwall, very small fissures 
 in the strata of the earth, through 
 which small streams of water flow 
 when they are opened by the work- 
 ing underground, greatly to the 
 hindrance of the workmen. 
 
 Casing of timber-work, the plastering 
 a house all over on the outside with 
 mortar and then striking it wet by 
 a ruler with the corner of a trowel, 
 or the like instrument, to make it 
 resemble the joints of freestone, 
 by which means the whole house 
 appears as if built thereof. 
 
 Casino. The Italian name used at 
 first for a small house, afterwards 
 a pleasure-house in a garden, and 
 then for a place of relaxation in 
 town. 
 
 Cassel earth, or Castle earth, an 
 ochreous pigment of a brown co- 
 
 85 
 
 lour, more inclined to the russet 
 hue. 
 
 Cassia Fistula is a native vegetable 
 pigment, though it is more com- 
 monly used as a medicinal drug. 
 
 Cast, to pay a vessel's head off, in 
 getting under \vay, on the tack she 
 is to sail upon. 
 
 Cast after cast, in Cornwall, is throw- 
 ing up of tin stuff, etc., from one 
 stage of boards to another, each 
 cast about 5 or 6 feet high. 
 
 Castella, square towers in the ce- 
 lebrated Roman wall of Severus, 
 which was raised to separate Eng- 
 land from Scotland. 
 
 Castellated, built in imitation of an 
 ancient castle. 
 
 Castellum, the receptacle in which 
 the water was collected and heated 
 for the public baths of the Romans; 
 a castle. 
 
 Casting, among sculptors, the taking 
 casts of impressions of figures, 
 busts, medals, leaves, etc. 
 
 Casting of draperies : by this term is 
 implied the distribution of the 
 folds, and draperies are said to be 
 well cast when the folds are dis- 
 tributed in such a manner as to 
 appear rather the result of mere 
 chance than of art, study, or labour. 
 In that manner or style of painting, 
 which is called the grand, the folds 
 of the draperies should be great, 
 and as few as possible, because 
 their rich simplicity is more sus- 
 ceptible of great lights ; but it is 
 an error to design draperies too 
 heavy and cumbersome, for they 
 ought to be suitable to the figures, 
 with a combination of ease and 
 grandeur. Order, contrast, and a 
 variety of stuffs and folds, consti- 
 tute the elegance of draperies ; and 
 diversity of colours in these stuffs 
 contributes extremely to the har- 
 mony of the whole in historic com- 
 positions. 
 
 Casting or Warping, in joinery, is the 
 bending of the surfaces of a piece 
 of wood from their original posi- 
 tion, either by the weight of the 
 wood or by an unequal exposure to 
 
CAS 
 
 CASTLE. 
 
 CAT 
 
 the weather, or by the unequal tex- 
 ture of the wood. 
 
 Cast-iron framing, for mill-work, 
 possesses great superiority over 
 that of timber, for constructing 
 the framing. It is not only much 
 more durable, but, from the uni- 
 formity of its texture, may be con- 
 verted into any shape, so as to give 
 it great advantage in arranging the 
 materials with respect to strength, 
 and proportioning it to the stress 
 it has to sustain. 
 
 Cast-iron shoes for roofs. A practice 
 has been recently introduced into 
 the , construction of roofs having 
 the beams of wood, of protecting 
 their extremities from the damp 
 and consequent decay to which 
 they are liable, by resting imme- 
 diately in contact with the brick 
 or stone work of the walls of the 
 building. This is effected by what 
 the workmen call cast-iron shoes, 
 which are attached to the ends of 
 the tie-beams by means of bolts, 
 nuts, etc. 
 
 The iron shoe itself, of course, 
 takes various forms, according to 
 circumstances and the situation 
 where it is introduced, and the 
 particular views of the architect 
 who employs it. 
 
 In cases where, from the nature 
 of the work carried on, every part 
 is exposed to great heat and mois- 
 ture, the defence afforded by such 
 an attachment is of great import- 
 ance ; the wood, unless thus pro- 
 tected, being of course very liable 
 to decay in those parts where damp 
 and moisture might accumulate. 
 
 Castle, a fortified arid strong man- 
 sion, situated and constructed and 
 arranged for the purpose of pro- 
 tecting its inmates against the as- 
 saults of enemies ; in modern use, 
 domestic residences of the nobi- 
 lity and gentry, without the neces- 
 sity of being garrisoned by armed 
 men. 
 
 Cat, the tackle used to hoist the an- 
 chor up to the cat-head. 
 
 Catacombs, subterraneous vaults or 
 
 8G 
 
 excavations used as burying-places. 
 
 Catadrome, a tilt-yard, or place where 
 horses run for prizes ; also an en- 
 gine like a crane, used by builders 
 to draw up or let down any weight. 
 
 Catafalco, a decoration of sculpture, 
 painting, etc., raised on a timber 
 scaffold, to show a coffin or tomb 
 in a funeral solemnity. 
 
 Catagraph, the first draught of a 
 picture. 
 
 Catamaran, a name given both in the , 
 East and West Indies to some kinds 
 of rafts, which are used in short 
 navigations along the sea-shore. 
 
 Cataract, a contrivance applied to 
 Cornish engines for regulating the 
 number of strokes per minute : it 
 consists of a small pump fixed on 
 a cistern ; the piston is raised at 
 each stroke of the engine by a 
 tappet on the plug-rod, and the 
 water rises into the cylinder of the 
 pump ; it is then forced through a 
 cock by means of counterweights 
 attached to a cross-head on the 
 pump piston-rod : when the water 
 has been forced back into the 
 cistern, a series of levers, acting on 
 a rising rod, loosen catches which 
 allow weights to act, by means of 
 levers, to open or shut the steam, 
 equilibrium, and exhaust valves. 
 
 Cataractes, a cataract, cascade, or 
 sudden fall of water from a higher 
 to a lower level ; according to 
 Pliny, a sluice, flood-gate, or lock 
 in a river. 
 
 Catch, a contrivance in machinery, 
 acting on the principle of a latch. 
 
 Catenary, in the higher geometry, a 
 mechanical curve which a chain or 
 rope forms itself into by its own 
 weight, when hung freely between 
 two points of suspension, whether 
 these points be in the same hori- 
 zontal plane or not. 
 
 Catgut, in turnery, the string which 
 connects the fly and the mandril. 
 
 Cat-harpin, an iron leg used to con- 
 fine the upper part of the rigging 
 to the mast. 
 
 Catharpings, small ropes in a ship, 
 running in little blocks, from one 
 
CAT 
 
 CATHEDRALS. 
 
 CAU 
 
 side of the shroud to another, near 
 the deck. 
 
 Cat-head, in naval architecture, a 
 large square piece of timber, one 
 end of which is fastened upon the 
 forecastle and the other end pro- 
 jects without the how, so as to keep 
 the anchor clear of the ship when 
 it is being drawn up by a tackle. 
 
 Cathedra, according to Horace, a chair 
 without arms; according to Juve- 
 nal, a chair with a long deep seat. 
 
 Cathedral, the principal church of a 
 diocese, in which the bishop's 
 throne is placed. 
 
 Very few of the Gothic cathe- 
 drals on the Continent have the 
 tower or spire springing from the 
 centre of the cross, and resting 
 on four pillars, to balance the 
 thrusts of the ranges of arches 
 centering there ; nor have those of 
 Strasburg, Ulm, Vienna, Orleans, 
 or Antwerp. " The distribution of 
 light in a Gothic cathedral is ad- 
 mirably adapted to the grandeur of 
 the edifice, and produces that effect 
 which a painter aims at in his 
 picture. At the entrance at the 
 west, the window being placed high, 
 there is a low-toned light on the 
 lower part of the pillars, and a 
 shadow on the pavement, which, as 
 we walk up the nave, graduates into 
 light from the choir. The east 
 window, always the broadest and 
 the highest, pours in a greater body 
 of light than is to be found in any 
 other kind of building. The altar, 
 rather in shadow, surrounded by 
 this strong light, gives additional 
 effect by contrast. The light from 
 the transept windows is softened 
 down by painted glass. The small 
 windows, placed high along the 
 aisles, enlighten their roofs, but 
 the lower part of the pillars and 
 floor remain in shadow." 
 
 Cathedral (the very ancient) of Usum- 
 bar and other Armenian churches 
 in Georgia have an arcade sur- 
 rounding the outside of the build- 
 ing, of which the arches are in the 
 flattened Gothic style : the same 
 
 87 
 
 form prevails in the windows, doors, 
 etc., in the body of the church. 
 These structures are of an earlier 
 date than any Gothic architecture 
 in Italy. 
 
 Catherine-wheel, in architecture, an 
 ornament that occurs in the upper 
 part of the north and south tran- 
 septs of ancient cathedrals. 
 
 Catherwood (Frederick), architect, 
 born in London 1799: his travels 
 were extensive ; had much to do 
 both in North and South America ; 
 was lost in the Arctic in 1854. 
 
 Cathetus. The eye of the volute is 
 so termed because its position is 
 determined, in an Ionic or voluted 
 capital, by a line let down from the 
 point in which the volute generates. 
 
 Cathimia, a subterraneous mineral 
 vein, out of which gold and silver 
 are dug. 
 
 Cat's-paw, a hitch made in a rope. 
 
 Cauliculus, the volute or twist under 
 the flower in the Corinthian capital. 
 
 Caulking, in naval architecture, the 
 art of driving a quantity of oakum, 
 i.e. old ropes untwisted and soft- 
 ened, into the seams of the planks, 
 to keep out the water. 
 
 Gaunter and Caunting, in Cornish 
 mining, Contra : when two lodes 
 run across, the one, with respect to 
 the other, is called a counter or 
 contra lode. 
 
 Cans (S. de), born in France, was 
 drawing-master to Henry Prince of 
 Wales : he published several scien- 
 tific works. Died in 1614. 
 
 Caus (J. de), of Dieppe, brother of 
 the above, hydraulic engineer. 
 
 Causeway, a carriage-road. 
 
 Cautions in Architectural Construc- 
 tion. 
 
 UNION OF NEW AND OLD WORK. 
 
 In attaching any new work to a 
 building, every allowance must be 
 made for the sinking of the footings 
 under pressure, and for the settle- 
 ment of the masonry into itself. 
 Thus, while it is necessary that a 
 vertical groove, or indent, be made 
 in the old work, to receive a cor- 
 
CAU 
 
 CAUTIONS IN 
 
 CAU 
 
 responding piece of the new, it js 
 still more essential that a freedom 
 for the downward motion of the 
 latter should be secured : otherwise, 
 if it be tightly toothed and bonded 
 into the old work, the result illus- 
 trated in the annexed sketch may 
 be anticipated. 
 
 UNION OF ASHLAR FACING WITH 
 BRICK OR RUBBLE BACKING. 
 
 The same caution required in 
 the latter case must be here equally 
 observed. The backing (composed 
 of small material and much mor- 
 tar) will settle more than the face ; 
 and the latter will consequently 
 
 bulge. This is easily remedied by 
 computing, and allowing for, the 
 difference of settlement ; and by a 
 due regard to the occasional bond- 
 ing of the ashlar, so as to make 
 the wall one substance, instead of 
 two differently conditioned. The 
 preceding sketch illustrates the 
 consequence of weight pressing 
 
 88 
 
 upon unbonded ashlar and upon 
 yielding rubble. 
 
 INVERTED ARCHES. 
 
 Inverted arches must be used 
 cautiously. Here is an instance, 
 
 in which the points A and A were 
 prevented by the inverted arch 
 from sinking with the points B B, 
 which latter sunk the more from 
 the pressure of the arch c in the 
 direction of the dotted lines. It 
 is not uncommon for the young 
 architect to affect precautionary 
 science, without a due considera- 
 tion of the peculiar circumstances 
 of his case. 
 
 DRAINAGE, ETC. 
 
 Always endeavour, if possible, to 
 get your water-closet cess-pit out- 
 side the building, so that it may 
 be approached for cleansing with- 
 out disturbing the interior. Be 
 careful in the efficient use of dip- 
 draps to prevent the ascent of rats 
 from the outer sewer into the 
 drains which are under the floors 
 of the house. Rats are destructive 
 in their operations, and if they die 
 in the drain, prove, for a length 
 of time, an unbearable nuisance. 
 Drains may serve every purpose of 
 carrying off soil and water; but 
 the slightest opening in their upper 
 part will allow the escape of effluvia 
 into the space under the ground 
 flooring, and thence into the rooms, 
 unless that space be thoroughly 
 ventilated with grated openings, 
 allowing a thorough draught, or, 
 
'CAU 
 
 CONSTRUCTION. 
 
 CAU 
 
 at least, a free ingress of fresh air, 
 and equal egress of foul. In the 
 application of covered dry areas 
 round the excavated basements of 
 buildings, on no account omit their 
 entire ventilation. If this be not 
 attended to, the main walling, 
 which they are intended to preserve 
 from damp, may remain even more 
 continually moist than if in imme- 
 diate connection with the natural 
 ground. Moisture frequently rises 
 up the walling from below its foun- 
 dation, and, exuding from the face 
 of the masonry, remains confined, 
 unless it evaporate and escape. 
 Without means to this end, a co- 
 vered area will be merely a recep- 
 tacle for damp, and may keep the 
 masonry continually wet, even when 
 the ground outside is perfectly dry. 
 Be especially cautious that the 
 water from the rain- pipes of the 
 roofs and flats be not conducted 
 by them into the foundations. 
 
 FIRE OPENINGS. 
 
 It will save much subsequent 
 trouble and disturbance of masonry, 
 to be assured as to the size and 
 character of the stoves, grates, 
 ranges, etc., which the proprietor 
 will employ. In the kitchen and 
 cooking-rooms, especially, precau- 
 tionary care should be taken in 
 suiting the openings to the intended 
 apparatus. Do riot forget to be 
 prepared for a smoke-jack, etc. 
 
 DWARF WALLS. 
 
 In constructing these, do not 
 omit the holes, etc., necessary for 
 under-floor ventilation. 
 
 PAVING. 
 
 Be careful that the bottom, on 
 which fine paving is laid, be dry 
 and free from staining material. 
 Common lime mortar is often in- 
 jurious to pavements. Portland 
 paving is especially liable to be 
 disfigured by it. 
 
 WROUGHT STONE-WORK. 
 
 In putting wrought stone-work 
 together, iron is to be avoided as 
 
 89 
 
 the certain cause of its subsequent 
 destruction. The stone cornices, 
 architraves, and dressings of many 
 a noble mansion have been brought 
 into premature ruin by the con- 
 traction and expansion of iron 
 under the effects of cold and heat. 
 But there are careless contractors 
 who will allow their Corinthian 
 capitals and fluted shafts to be 
 ruined, even before the entablature 
 surmounts them ; and the young 
 architect will not, therefore, omit 
 to insert a clause in his specifica- 
 tion (and to be peremptory in its 
 enforcement), that all cut stone- 
 work be securely preserved, during 
 the progress of the building, with 
 wood casing. It is surprising how 
 grossly indifferent each class of 
 artificers is to the work of the 
 others. It is still more surprising 
 to observe how frequently they 
 seem indifferent to the preserva- 
 tion of their own. 
 
 SLATING. 
 
 Get rid of the masons and plas- 
 terers and plumbers before your 
 slaters begin. The injury done to 
 slating by the afterwork of chim- 
 ney-tops, etc., is much to be 
 dreaded. The cementitious ' stop- 
 ping ' to a roof will not be effi- 
 ciently done without close super- 
 vision : the ridge, hip, and valley 
 courses will not be properly formed 
 of large cut slates, nor will every 
 slate have its two nails, unless the 
 architect see to it. 
 
 PLASTERING. 
 
 Clear may be your specification 
 in forbidding salt sand, but, if your 
 work be carried on in the vicinity 
 of any estuary, the chances are 
 (unless you be deemed cruelly 
 strict) that the surface of your in- 
 ternal walls will vary with the 
 weather, from damp to dry, like a 
 seaweed, and throw out salt in 
 abundance. 
 
 BEAMS, JOISTS, AND OTHER TIMBERS. 
 LINTELS, BOND, PARTITION'S. 
 
 It is the office of walls to carry 
 
CAU 
 
 CAUTIONS IN 
 
 CAU 
 
 beams, etc. ; and that of beams to 
 stay the walls from falling otfl- 
 wards or inwards : but it is the 
 duty of architects to see that the 
 wood- work which supplants ma- 
 sonry does not weaken the latter ; 
 t. e. that the ends of timbers in- 
 serted into walls may not, by com- 
 pression or decay, leave the su- 
 perincumbent masonry to loosen 
 downwards. Thus, the beam A, 
 though entering only a portion of 
 
 the wall,presses uponthe thorough- 
 stone e, which throws the weight 
 upon the whole wall, and has, by 
 means of an iron plate c, a hold to 
 secure its perpendicularity. The 
 cover-stone c presses on the surface 
 of the timber to confirm its secu- 
 rity : but should the timber rot, 
 the cover-stone will not sink, be- 
 cause sustained by the side-stones 
 dd. To prevent rot, the backing 
 and side-stones are left free of the 
 timber, so that air 
 may traverse round 
 it. The habit of plac- 
 ing the ends of beams 
 on a template, as G, 
 is bad. The only jus- 
 tification of the employment of 
 wood, so built into the walls, is 
 when it forms a continuous plate, 
 that it may act as a bond to pre- 
 serve the perfect horizontal level of 
 joists, which, however, should ex- 
 
 tend a little beyond the plate, so as 
 to have a bearing also on the solid 
 of the wall. Careful inspection 
 
 will then so manage the construc- 
 tion of the wall in this part, as to 
 leave it but little weakened by the 
 air-hollows required for the plate 
 
 and joists : unless, indeed, it be 
 very thin, as only one brick, for 
 instance, when no law of common 
 sense can justify the use of conti- 
 nuous bond. Where joists uninter- 
 ruptedly cross a thin wall, which 
 is to support another story of ma- 
 sonry, let there only be one plate, 
 thin, and on its edge, in the centre 
 of the wall, so that at least a brick 
 on edge may be placed on each 
 side of it, to fill up the intervals 
 between the joists, and give solid 
 support to the superincumbent 
 masonry. On no account let the 
 upper part of the wall be separated 
 from the lower by a mere layer of 
 perishable wood, or supported by 
 a range of joists on their edge. It 
 has often been seen that iron hoop- 
 ing should be more used than it is 
 as the internal bonding of walls. 
 At the same time it must be re- 
 membered that bond timbering is 
 necessary, at intervals, to receive 
 the nails of the battening. When, 
 however, the wall is thin, it may 
 be imperative to avoid its use, 
 employing old oak bats for that 
 purpose. In short, let it be the 
 care of the young architect, so to 
 contrive the union of his masonry 
 and carpentry, as that the entire 
 removal of the latter may leave the 
 
 90 
 
;AU 
 
 CONSTRUCTION. 
 
 CAU 
 
 former secure in its own strength. 
 In the use of lintels especially, he 
 should be cautious. They are use- 
 ful as bonds to unite the tops of 
 piers, and as means for the fixing 
 of the joinery ; but they ought 
 never to be trusted to as a lasting 
 support of masonry, that support 
 being always really afforded by the 
 relieving segment arch above the 
 lintel. A bressummer may be 
 termed a large lintel ; and by its 
 adoption here, at least, the support 
 of the masonry is truly intended. 
 The use of the bressummer, in shop- 
 front openings, is an evil necessity 
 to which an architect must often 
 submit ; and all that he can do, is 
 to make the best of a bad job, by 
 wrought -iron trussing, which will 
 at least give adequate strength, 
 though it may not ensure perma- 
 nent durability. If time spare it, 
 fire may destroy it ; and the latter 
 evil is not to be met even by iron, 
 which, if wrought, will bend, if 
 cast, will crack, with heat. Let 
 the arch, then, or some modifica- 
 tion of it, be always used, if pos- 
 sible. 
 
 Partitions of wood should not be 
 left to the sagacity of the carpenter. 
 Under all circumstances where they 
 have to support themselves over 
 voids, or to bear, or participate in 
 the bearing of, a pressure from 
 above, they should be considered 
 
 by the architect in his specifica- 
 tion, and carefully studied in 
 making the working drawings. It 
 
 91 
 
 is not enough merely to say, that 
 " they are to be trussed so as to pre- 
 vent any injury to ceilings by their 
 own pressure;" marginal sketches 
 should be made, showing the dis- 
 position of the skeleton framing, 
 with whatever iron-work is neces- 
 sary to its security. See, for in- 
 stance, what a carpenter may do, 
 unless well directed : a roof c, 
 bearing partly on the partition A, 
 when it should have borne only on 
 the walls ; and, instead of distress- 
 ing the partition, should hare 
 rather held it suspended : the par- 
 tition A bearing down with its own 
 weight, and that of the roof, on 
 the floor B, instead of being so 
 truss-framed in its length as to 
 leave the floor unconscious of its 
 existence. No ignorance in the 
 young architect is presumed as to 
 the manner of doing these things ; 
 he is merely admonished not to 
 imagine that they are so obvious as 
 to be done without his guidance. 
 In the framing of roofs, give a 
 
 maximum strength to the purlins : 
 the undulating surface of a weakly- 
 purlined roof will soon proclaim 
 its defect in this particular. The 
 position of the principals should 
 not be observable from without. 
 
 FLOORS J SIMPLE AND FRAMED, ETC. 
 
 For permanent and uniform 
 strength, there is no floor so good 
 as one composed of simple joists, 
 stiffened by cross-bonding : but, in 
 very large rooms, there is more 
 economy in the compound floor of 
 binders and joists, or of joists, 
 binders, and girders. There may 
 be particular reasons for girders, 
 etc.; as, when the weight of the 
 floor has to be thrown upon 
 
CAU 
 
 CAUTIONS. 
 
 CAU 
 
 piers, and not on a continuous 
 wall of uniform strength : but 
 the usual motive to the use of the 
 compound floor, in rooms which 
 exceed 18 or 20 feet in width, is a 
 legitimate economy of materials. 
 It is only necessary to caution the 
 young practitioner on the necessity 
 of considering, that girders have to 
 perform the duty of cross-walls ; 
 that they should be trussed to 
 prevent their ' sagging ' even with 
 their own weight ; that their scant- 
 ling should allow for the weakening 
 effect of the cuttings made into 
 their substance to receive the tim- 
 bers they support ; that their truss- 
 es should be wholly of iron (and 
 not partially of oak) ; and, espe- 
 cially, that the end of each girder, 
 instead of being notched on perish- 
 able templates of wood, and closely 
 surrounded with mortar and ma- 
 sonry, should be housed in a cavity 
 with an iron holding-plate ; or 
 inserted into a cast-iron boxing, 
 notched into a thorough - stone, 
 leaving a space (however small) 
 for the air to circulate about it, 
 
 and prevent rot. The failure of 
 a girder sometimes involves the 
 failure of all the rest of the floor : 
 and, though all timbers inserted 
 in masonry should have a more 
 careful regard to their preservation 
 from decay than it is usual to be- 
 stow, it will be readily admitted, 
 that too much care cannot be given 
 to those leading bearing timbers, 
 without the permanent duration of 
 which the durability of the large 
 remainder is of no avail. 
 
 ROOFS. 
 The same remarks, applying to 
 
 92 
 
 the extremities of girders, apply 
 also to tie-beams. 
 
 CEILINGS. 
 
 To procure a good ceiling in 
 single-joist floors it is necessary 
 there should be ceiling-joists cross- 
 ing below the others : and it is a 
 question whether the ceiling-joists, 
 under double-framed floors, instead 
 of being chase-mortised into the 
 binders, should not be in unbroken 
 lengths nailed under the binders. 
 Where the ceiling-joists (as under 
 roofs) are likely to be trodden 
 upon, they must be well secured. 
 
 SOUND BOARDING. 
 
 Always consider whether the 
 occupants of any particular room 
 will be annoyed by noises from the 
 rooms below or above. Sound 
 boarding and pugging considerably 
 increase the weight of the floor, 
 the scantling of whose timbers 
 should therefore be thought upon. 
 Watercloset partitions should be 
 well pugged. 
 
 MICE IN PARTITIONS AND SKIRT- 
 INGS. 
 
 The space behind the skirtings 
 is often a thoroughfare 
 for mice, which also 
 contrive to travel from 
 floor to floor in the 
 hollows of the quarter- 
 partitions, and become 
 in several ways a great 
 nuisance. Plaster or 
 wood stopping is not 
 . always so efficacious as 
 the use of broken glass 
 in those secret passages which they 
 are prone to frequent. 
 
 COVERINGS TO GUTTERS, CISTERNS, 
 ETC. 
 
 The liability of gutters and 
 cisterns to become choked with 
 snow, or filled up with leaves, etc., 
 renders it advisable to protect them 
 with a boarded covering, which 
 may preserve the under-current of 
 water from receiving what may 
 
CEDARS. 
 
 CED 
 
 speedily produce a chokage or 
 overflow. 
 
 IKON COLUMNS, BEAMS, ETC. 
 
 On this most important subject 
 the young architect should not 
 move a step without carefully con- 
 sulting the experienced knowledge 
 of the engineer. Tredgold's ' Prac- 
 tical Essay on the Strength of Cast 
 Iron ' should be well studied, 
 whenever necessity compels the 
 support of heavy and loaded su- 
 perstructures by iron columns and 
 beams. A careful computation of 
 the weight of the mere building, 
 added to that of its possible bur- 
 then, with allowance for theoretical 
 fallacy, and a due estimate of the 
 increased strength of the hollow 
 pillar, as compared with a solid 
 one having the same amount of 
 metal, must be made, examined, 
 and re-examined, before the speci- 
 fication be issued. 
 
 Cavcedium, one of the courts of a 
 Roman house, most commonly sur- 
 rounded by a covered passage, 
 having the middle area exposed to 
 the air. There are five kinds of 
 cavaedia, which, from their mode 
 of construction, are severally deno- 
 minated Tuscan, Corinthian, tetra- 
 style, displuviatum, and testudi- 
 natum. They are termed Tuscan 
 when the beams which are thrown 
 across the court have timbers and 
 gutters extending diagonally from 
 the angles made by the walls of the 
 court to those made by the junction 
 of the beams, and the rafters of the 
 eaves are made to incline every 
 way towards the centre of the 
 compluvium. The timbers and 
 compluvia of Corinthian cavaedia 
 have a disposition, in all respects, 
 similar ; but beams are made to 
 project from the walls, and are 
 supported upon columns arranged 
 around the court. 
 
 Cavazion, in architecture, the hollow 
 trench made for laying the foun- 
 dation of a building ; according to 
 
 93 
 
 Vitruvius, it ought to be one-sixth 
 part of the height of the whole 
 building. 
 
 Cavetto, a hollow moulding whose 
 profile is a quadrant of a circle ; 
 principally used in cornices. 
 
 Cavendish (the Hon. Henry), one of 
 the most learned men in chemistry 
 and the arts of his age. Born 10th 
 October 1731 ; died 24th Febru- 
 ary, 1810. An octavo volume, pub- 
 lished by the Cavendish Society 
 in 1851, very copiously adduces 
 evidences of Mr. Cavendish's prior 
 claim to the discovery of the theory 
 of the composition of air and 
 water : the volume contains many 
 valuable papers on the life and 
 experimental labours of Cavendish, 
 and the relative merit of Cavendish ; 
 on Watt and Lavoiser and others ; 
 inquiries of the learned men of the 
 latter end of the last, and the be- 
 ginning of the present century. 
 
 Cawk-stone, a mineral, akin to the 
 white milky, mineral juice of lead 
 mines. 
 
 Caya, a kay or water-lock. 
 
 Cede, an old English term for a ca- 
 nopy. 
 
 Cedar. Cedar-wood was known an d 
 used in the earliest times, as in the 
 construction of Solomon's Temple : 
 great varieties are produced in the 
 eastern and western parts of the 
 world : it is used in ship-building, 
 cabinet-work, pencil-making, and 
 for various other purposes. 
 
 Cedars of Lebanon, of great age and 
 size, constitute a peculiar and very 
 observable feature in the landscape 
 of the suburbs of London, and are 
 unusually numerous on the west 
 and south-west sides as the ad- 
 juncts of stately mansions or ele- 
 gant villas, along the valley of the 
 Thames. 
 
 Poplars (Lombardy) are very 
 freely introduced into the scenery 
 around London. Beeches do not 
 appear at home anywhere along the 
 flat grounds near the Thames; but 
 at Burnham, a little below Slough, 
 there are some celebrated ones, 
 
CEI 
 
 CEMENTS. 
 
 CEM 
 
 growing on a thin, light, gravelly 
 soil, and Windsor Park contains 
 some superb specimens. 
 
 Chestnuts (of Spanish) we shall 
 have some prodigious specimens to 
 notice on a property of the Duke 
 of Devonshire, near Chiswick. In 
 Kensington Gardens, Greenwich 
 Park, and other places, there are 
 some very fine ones. It is a first- 
 rate park tree for the low sheltered 
 tract by the sides of the Thames, 
 and is hardly enough esteemed. 
 
 Ceiling, the upper side of an apart- 
 ment, opposite to the floor, gene- 
 rally finished with plastered work. 
 Ceilings are set in two different 
 ways : the best is where the setting- 
 coat is composed of plaster and 
 putty, commonly called ' gauge.' 
 Common ceilings have plaster, but 
 no hair: the latter is the same as 
 the finishing coat in walls set for 
 paper. 
 
 Ceiling, the under covering of a roof, 
 under the surface of the vaulting in 
 vaulted rooms and buildings. Ceil- 
 ings in buildings of any dimensions 
 at either story are the upper or 
 overhead surfaces of the rooms 
 respectively. 
 
 Ceilings. When ceilings are covered, 
 the height of the cove should be 
 regulated by the total height of the 
 room. In proportioning the height 
 of a room to its superficial dimen- 
 sions, the best proportion for the 
 cove is one-quarter of the whole 
 height. 
 
 Celerity is the velocity or swiftness 
 of a body in motion ; or that affec- 
 tion of a body in motion by which 
 it can pass over a certain space in 
 a certain time. 
 
 Cell, an enclosed space within the 
 walls of an ancient temple ; a term 
 applied also to monkish sleeping- 
 rooms in religious establishments. 
 
 Cella, the body or principal part of a 
 temple, anciently written cela. 
 It is thought to be derived from 
 celandus, to be concealed or shut 
 out from public view ; because 
 in early emple the cella could 
 
 94 
 
 only be entered by privileged 
 persons. 
 
 Cellarino, that part of the capital in 
 the Roman, Doric, and Tuscan 
 orders which is below the annulets 
 under the ovolo. 
 
 Cellular beam. A newly introduced 
 application of wrought-iron to the 
 ' purposes of girders and beams, ir 
 which wrought-iron plates are 
 riveted with angle-irons in the 
 form of a series of longitudinal 
 cells with occasional struts. 
 
 Cemetery, a place wherein the bodies 
 of the dead are buried ; a church- 
 yard or burying-ground. 
 
 Cementation is the process of con- 
 verting iron into steel, which is 
 done by stratifying bars of iron ini 
 charcoal, igniting it, and letting! 
 them continue in a kiln in that state 
 for five or six days : the carbon of 
 the charcoal is thus absorbed by 
 the iron, and the latter converted 
 into steel. 
 
 Cements, natural. When the propor- 
 tion of clay in calcareous minerals 
 exceeds 27 to 30 per cent., it is 
 seldom that they can be converted 
 into lime by calcination ; but they 
 then furnish a kind of natural ce- 
 ment, which may be employed in 
 the same manner as plaster of Paris, 
 by pulverizing it, and kneading it 
 with a certain quantity of water. 
 
 There are some natural cements 
 which do not set in water for many 
 days, and some which harden in 
 less than a quarter of an hour : 
 these last are the only ones which 
 have been made use of at present. 
 Though very useful in circum- 
 stances where a quick solidification 
 is indispensable, they are far from 
 affording, in ordinary cases, the 
 advantages of hydraulic mortars or 
 cements of good quality. In fact, 
 they merely adhere to the stone, 
 owing to the roughness of its sur- 
 face, and the entanglement result- 
 ing from it ; and, however dexterous 
 or experienced the workman may 
 be who makes use of them,he will 
 be unable to connect the different 
 
CEM 
 
 CEMENTS. 
 
 CEM 
 
 parts of his masonry in one conti- 
 nuous bond by means of them. 
 This statement must be understood 
 to apply only to cements which 
 harden while in contact with bricks 
 under water, because the adhesion 
 of such as dry in the open air is 
 well known to be much greater 
 than what would be caused merely 
 by asperities of the surface. It is 
 not uncommon to see from twenty 
 to thirty bricks stuck to one an- 
 other by Roman cement, and pro- 
 jecting at right angles from the 
 side of a wall, as a proof of the 
 excellence of the composition ; and 
 an instance has been mentioned in 
 which thirty-three bricks were suc- 
 cessfully supported in this manner. 
 Now, if we assume the weight of a 
 brick and its corresponding joint 
 of cement to be 6 ft>s., and their 
 thickness, when the bricks were 
 joined one to another in the man- 
 ner above alluded to (in which the 
 longest dimension of the brick was 
 placed vertically), to be 2^ inches, 
 then the cohesive force necessary 
 to unite the first brick to the wall, 
 with sufficient firmness to bear the 
 strain occasioned by the weight of 
 the remaining thirty-two supported 
 by it, must have been nearly Qllfes. 
 per square inch, or equivalent to a 
 direct load of 3640 fts. upon its 
 whole surface of about 40 square 
 inches. 
 
 That which is in England very 
 improperly termed Roman cement 
 is nothing more than a natural ce- 
 ment, resulting from a slight calci- 
 nation of a calcareous mineral, 
 containing about 31 per cent, of 
 ochreous clay,and a few hundredths 
 of carbonate of magnesia and man- 
 ganese. A very great consumption 
 of this cement takes place in Lon- 
 don ; but its use will infallibly be- 
 come restricted, in proportion as 
 the mortars of eminently hydraulic 
 lime shall become better known, 
 and, in consequence, better appre- 
 ciated. 
 
 Very recently, natural cements 
 
 95 
 
 have been found in Russia and in 
 France. They may be composed at 
 once by properly calcining mix- 
 tures made in the average propor- 
 tions of 66 parts of ochreous clay 
 to 100 parts of chalk. It is fair, 
 however, to admit, that no artificial 
 product has yet been proved to 
 equal the English cement in point 
 of hardness. 
 
 The pure calcareous substances, 
 when imperfectly calcined, become 
 converted into sub-carbonates, pos- 
 sessed of certain properties. These 
 properties are to afford a powder, 
 which, when kneaded with water 
 in the same way as plaster of Paris, 
 acquires in it, at first, a consistency 
 more or less firm, but which does 
 not continue its progress at the 
 same rate. 
 
 The argillaceous limestones, and 
 the artificial mixtures of pure lime 
 and clay in the proportions requi- 
 site to constitute hydraulic lime by 
 the ordinary calcination, become 
 natural or artificial cements when 
 they have been subjected merely 
 to a simple incandescence, kept up 
 for some hours, or even for some 
 minutes. This result, which has 
 often occurred in the course of 
 first experiments in burning the 
 artificial hydraulic limestones, has 
 been equally observed in Russia by 
 Colonel Raucourt ; and M. Lacor- 
 daire, Engineer of Roads, has not 
 only fully verified it with respect 
 to the different argillaceous lime- 
 stones of the neighbourhood of 
 Pouilly, but has also made a use- 
 ful and happy application of it in 
 the works which have been erected 
 at the junction of the Burgundy 
 canal ; both in transforming these 
 limestones into natural cements, 
 and in turning to account the large 
 quantity of half-burnt lime which 
 is found in the upper layers of the 
 kilns, when the intensity and du- 
 ration of the heat is so regulated 
 as not to exceed the limit proper 
 for the lower strata of the charge. 
 
 The history of these new cements 
 
CEN 
 
 CENTRE FRAMES. 
 
 CEN 
 
 will not be complete until authentic 
 and multiplied experiments shall 
 have established their power to 
 resist the effects of air and frost, 
 and the degree of adhesion with 
 which they unite to the building- 
 stone. 
 
 Cenotaphium, a cenotaph, an empty 
 or honorary tomb, erected by the 
 Greeks as a memorial of a person 
 whose body was buried elsewhere, 
 or not found for burial. 
 
 Censitores, surveyors of the Roman 
 aqueducts. 
 
 Centaur, poetically, and in ancient 
 mythology, a being represented as 
 half man half horse ; the Sagitta- 
 rius of the Zodiac. 
 
 Centering, temporary supports, prin- 
 cipally of timber, placed and affixed 
 under vaults and arches to sustain 
 them while they are in course of 
 building. Much ingenuity is dis- 
 played in the centering for bridges 
 and tunnels. 
 
 Centigrade, the division into grades 
 or degrees by hundredth parts ; 
 called also centesimal. 
 
 Central forces, the powers which 
 cause a moving body to tend to- 
 wards or recede from the centre of 
 motion. When a body is made 
 to revolve in a circle round some 
 r xed point, it will have a continued 
 tendency to fly off in a straight line 
 at a tangent in the circle, which 
 tendency is called the centrifugal 
 force ; and the opposing power by 
 which the body is retained in the 
 circular path is called the centri- 
 petal force. 
 
 Centre, any timber frame, or set of 
 frames, for supporting the arch- 
 stones of a bridge during the con- 
 struction of an arch. 
 
 The qualities of a food centre 
 consist in its being a sufficient sup- 
 port for the weight or pressure of 
 the arch-stones, without any sen- 
 sible change of form taking place 
 throughout the whole progress of 
 the work, from the springing of 
 the arch to the fixing of the key- 
 stone : it should be capable of being 
 
 96 
 
 easily and safely removed, and de- 
 signed so that it may be erected at 
 a comparatively small expense. 
 
 In navigable rivers, where a cer- 
 tain space must be left for the pas- 
 sage of vessels, and in deep and 
 rapid rivers, where it is difficult to 
 establish intermediate supports, 
 and where much is to be appre- 
 hended from sudden floods, the 
 frames should span the whole width 
 of the archway, or be framed so as 
 to leave a considerable portion of 
 the archway unoccupied. In such 
 cases, a considerable degree of art 
 is required to make the centre an 
 effectual support for the arch- 
 stones, particularly when the arch 
 is large. But in narrow rivers, and 
 in those where the above-mentioned 
 inconveniences do not interfere 
 with the work, the framing may be 
 constructed upon horizontal tie- 
 beams, supported in several places 
 by piles, or frames fixed in the bed 
 of the river ; and the construction 
 is comparatively easy. 
 
 In large arches, when the arch- 
 stones are laid to a considerable 
 height, they often force the centre 
 out of form, by causing it to rise 
 at the crown ; and it is sometimes 
 necessary to load the centre at the 
 crown to prevent such rising ; but 
 this is a very imperfect remedy. 
 Notwithstanding the subject has 
 been considered by several very 
 eminent men, their works are not 
 much calculated to instruct the 
 carpenter how to avoid this diffi- 
 culty : indeed, their object seems 
 to have been exclusively to calcu- 
 late the strength of a centre already 
 designed, instead of showing the 
 principles on which it ought to 
 be contrived ; and even in calcu- 
 lating the strength, they are very 
 imperfect guides, because they have 
 hot attempted to find what forces 
 would derange a centre, but only 
 the force that might be supported 
 without fracture. 
 
 Centre, in a general sense, denotes a 
 point equally remote from the ex- 
 
CEN 
 
 CENTRE-BIT. 
 
 CEN 
 
 tremes of a line, surface, or solid : 
 the word signifies a point. 
 
 Centre-bit, in joinery, an instrument 
 with a projecting conical point 
 nearly in the middle, called the 
 centre of the bit : on the narrow 
 vertical surface, the one most re- 
 mote from the centre, is a tooth 
 with a cutting edge. The under 
 edge of the bit on the other side of 
 the centre has a projecting edge 
 inclined forward. The horizontal 
 section of this bit upwards is a 
 rectangle. The axis of the small 
 cone in the centre is in the same 
 straight line as that of the stock ; 
 the cutting edge of the tooth is 
 more prominent than the projecting 
 edge on the other side of the cen- 
 tre, and the vertex of the conic 
 centre is still more prominent than 
 the cutting edge of the tooth. 
 
 The use of the centre-bit is to 
 form a cylindric excavation, having 
 the upper point of the axis of the 
 intended hole given on the surface 
 of the wood. The centre of the bit 
 is first fixed in this point ; then, by 
 placing the axis of the stock and 
 bit in the axis of the hole intended 
 to be bored, with the head of the 
 stock against the breast, and by 
 turning the stock swiftly round by 
 means of the handle, the hollow 
 cone made by the centre will cause 
 the point of the tooth to move in 
 the circumference of a circle, and 
 cut the cylindric surface progres- 
 sively as it is turned round, while 
 the projecting edge upon the other 
 side of the centre will cut out the 
 cone in a spiral-formed shaving. 
 Centre-bits are of various sizes, for 
 bores of different diameters. 
 
 Centre-chuck, a chuck which can be 
 screwed on the mandril of a lathe, 
 and has a hardened steel cone or 
 centre fixed in it ; also a projecting 
 arm or driver. 
 
 Centre-drill, a small drill used for 
 making a short hole in the ends of 
 a shaft about to be turned, for the 
 entrance of the lathe centres. 
 
 Centre of attraction of a body is that 
 
 97 
 
 point into which, if all its matter 
 were collected, its action upon any 
 remote particle would still be the 
 same as it is while the body retains 
 its own proper form ; or it is that 
 point to which bodies tend by 
 their own gravity, or about which 
 a planet revolves as a centre, being 
 attracted or impelled towards it by 
 the action of gravity. The common 
 centre of attraction of two or more 
 bodies is used to denote that point 
 in which, if a particle of matter 
 were placed, the action of each 
 body upon it would be equal, and 
 where it will remain in equilibrium, 
 having no tendency to move one 
 way rather than another. 
 
 Centre of a circle, that point in a 
 circle which is equally distant from 
 etery point of the circumference, 
 being that from which the circle 
 is described. 
 
 Centre of a conic section, that point 
 which bisects any diameter, or that 
 point in which all the diameters 
 intersect each other. This point 
 in an ellipse is within the figure, in 
 the hyperbola without, and in the 
 parabola it is at an infinite distance. 
 
 Centre of conversion, a mechanical 
 term, the signification of which may 
 be thus conceived : if a stick be 
 laid on stagnant water, and drawn 
 by a thread fastened to it, so that 
 the thread makes always the same 
 angle with it, the stick will be 
 found to turn about a certain point, 
 which point is called the ' centre 
 of conversion.' 
 
 Centre of a curve of the higher kind, 
 is the point where two diameters 
 concur ; and when all the diameters 
 concur in the same point, it is 
 called the general centre. 
 
 Centre of a dial, that point where 
 the gnomon or style, placed paral- 
 lel to the axis of the earth, inter- 
 sects the plane of the dial. 
 
 Centre of an equilibrium is the same 
 with respect to bodies immersed in 
 a fluid as the centre of gravity is 
 to bodies in free space ; or it is a 
 certain point on which, if a body, 
 
CEN 
 
 CENTRE OF GRAVITY. 
 
 CEN 
 
 or system of bodies, be suspended^ 
 they will rest in any position. 
 
 Centre of friction is that point in the 
 base of a body on which it revolves, 
 in which, if the whole surface of 
 the base and the mass of the body- 
 were collected and made to revolve 
 about the centre of the base of the 
 given body, the angular velocity 
 destroyed by its friction would be 
 equal to the angular velocity de- 
 stroyed in the given body by its 
 friction in the same time. 
 
 Centre of gravity of any body, or sys- 
 tem of bodies, is that point upon 
 which the body or system of bodies 
 acted upon only by the force of 
 gravity will balance itself in all 
 positions ; or it is a point on which, 
 when supported, the body or sys- 
 tem will be supported, however it 
 may be situated in other respects. 
 Hence it follows, that if a line or 
 plane passing through the centre 
 of gravity be supported, the body 
 or system will also be supported ; 
 and conversely, if a body or system 
 balance itself upon a line or plane, 
 in all positions, the centre of gravity 
 is in that line or plane. In a simi- 
 lar manner it will appear, that if a 
 body rest in equilibrio when sus- 
 pended from any point, the centre 
 of gravity of that body or system 
 is in the perpendicular let fall from 
 the centre of suspension ; and on 
 these principles depends the me- 
 chanical method of finding the cen- 
 tre of gravity of bodies. 
 
 Centre of gyration, that point in a 
 body revolving on an axis, into 
 which, if the matter of the whole 
 body were collected, the same an- 
 gular velocity would be generated 
 by the same moving force. 
 
 Centre of motion of a body is a fixed 
 point about which the body is 
 moved ; and the axis of motion is 
 the fixed axis about which it moves. 
 
 Centre of oscillation, the point in 
 which the whole of the matter 
 must be collected, in order that the 
 time of oscillation may be the same 
 as when it is distributed. 
 
 98 
 
 Centre of percussion, that point of a 
 revolving body which would strike 
 an obstacle with the same force as 
 if the whole of the matter were 
 collected in it. 
 
 Centre of position, in mechanics, de- 
 notes a point of any body, or system 
 of bodies, so selected that we may 
 properly estimate the situation and 
 motion of the body or system by 
 those points. 
 
 Centre of pressure, or metacentre of 
 a fluid against a plane, is that point 
 against which a force being applied, 
 equal and contrary to the whole 
 pressure, it will sustain it, so as 
 that the body pressed on will not 
 incline to either side. This is the 
 same as the centre of percussion, 
 supposing the axis of motion to be 
 at the intersection of this plane 
 with the surface of the fluid ; and 
 the centre of pressure upon a plane 
 parallel to the horizon, or upon any 
 plane where the pressure is uni- 
 form, is the same as the centre of 
 gravity of that plane. 
 
 Centre of spontaneous rotation, that 
 point which remains at rest the 
 instant a body is struck, or about 
 w r hich the body begins to revolve. 
 If a body of any size or form, after 
 rotatory or gyratory motions, be 
 left entirely to itself, it will always 
 have three principal axes of rota- 
 tion ; that is, all the rotary motions 
 by which it is effected may be con- 
 stantly reduced to three, which are 
 performed round three axes per- 
 pendicular to each other, passing 
 through the centre of gravity, and 
 always preserving the same position 
 in absolute space, while the centre 
 of gravity is at rest, or moves uni- 
 formly forward in a right line. 
 
 Centre phonic, in acoustics, the place 
 where the speaker stands in mak- 
 ing polysyllabical and articulate 
 echoes. 
 
 Centre phonocamptic, the place or 
 object which returns the voice. 
 
 Centre-punch., a small piece of steel 
 with a hardened point at one end. 
 
 Centres, in turnery, are the two cones 
 
CEN 
 
 CHAINS. 
 
 CHA 
 
 with their axes horizontally posited 
 for sustaining the body while it is 
 turned. 
 
 Centre-velic or Velic-point, the centre 
 of gravity of an equivalent sail, or 
 that single sail whose position and 
 magnitude are such as cause it to 
 be acted upon by the wind when 
 the vessel is sailing, so that the 
 motion shall be the same as that 
 which takes place while the sails 
 have their usual positions. 
 
 Centrifugal force is that force by 
 which a body revolving about a 
 centre, or about another body, has 
 a tendency to recede from it. 
 
 Centrifugal pump, a machine for 
 raising water by centrifugal force 
 combined with the pressure of the 
 atmosphere. 
 
 Centripetal force is that force by 
 which a body is perpetually urged 
 onwards to a centre, and thereby 
 made to revolve in a curve instead 
 of a right line. 
 
 Ceramics, a term for all the varieties 
 of baked or burnt clay. 
 
 Ctrium, a metal discovered in 1803 
 by Berzelius, and named after the 
 planet Ceres. It is brittle, white, 
 and volatile in a very intense heat : 
 it is not acted upon by nitric acid, 
 but is dissolved in aqua regia, nitro- 
 hydrochloric acid. 
 
 Cesspool, a receptacle, sunk below the 
 level of a drain from a privy or 
 water-closet, for the sediment 
 which would otherwise choke the 
 drain. 
 
 Cerceau (A. du), architect : practised 
 in France in 1575, and built se- 
 veral magnificent palaces and 
 mansions for Royalty and for the 
 nobility. 
 
 Cerceau (J. A. du), architect : born in 
 1516, at Orleans ; died in 1592. 
 He published valuable books on the 
 architecture of the period. 
 
 Ckafery, a forge in an iron mill, 
 wherein the iron is wrought into 
 bars. 
 
 Chain, in surveying, is a lineal mea- 
 sure, consisting of a certain number 
 of iron links, usually 100, serving 
 
 99 
 
 to take the dimensions of fields, 
 etc. : at every tenth link is usually 
 fastened a small brass plate, with 
 a figure engraved upon it, or else 
 cut into different shapes, to show 
 how many links it is from one end 
 of the chain. 
 
 Chains, strong links or plates of iron, 
 the lower ends of which are bolted 
 through a ship's side to the tim- 
 bers. 
 
 Chain-plates, plates of iron bolted to 
 the side of a ship, to which the 
 chains and dead-eyes of the lower 
 rigging are connected. 
 
 Chain-pump, an hydraulic machine 
 for raising water. It is made of 
 different lengths, and consists of 
 two collateral square barrels and 
 an endless chain of pistons of 
 the same form, fixed at proper 
 distances. 
 
 Chain- timber, in brick-building, a 
 timber of large dimensions placed 
 in the middle of the height of a 
 story, for imparting strength. 
 
 Chairs. Anciently, in most apart- 
 ments we find " two great chayers :" 
 these were arm-chairs, with stuffed 
 backs and sides, entirely covered, 
 and similar to the lounging-chairs 
 of the present day. Others are 
 described as 'Flemish chairs,' 
 ' scrolled chairs/ and < turned 
 chairs,' wrought in ebony, walnut, 
 cherry-tree, etc., with high backs, 
 either stuffed in one long upright 
 panel, or filled with wicker- work,etc. 
 
 Chalcedony, a precious stone, in co- 
 lour like a carbuncle; by some trans- 
 lated from the Scriptures as ' eme- 
 rald.' 
 
 Ckalcidicum, among the Romans, a 
 large, low, and deep porch, covered 
 with its own roof, supported on 
 pilasters, and appended to the en- 
 trance-front of a building, where 
 it protected the principal doorway, 
 and formed a grand entrance to the 
 whole edifice. 
 
 Chalcidria, chambers attached to a 
 basilica ; they were built at one end 
 when the situation would allow. 
 
 Chalcoyrapher, an engraver in copper. 
 
 F 2 
 
CHA 
 
 CHANTING. 
 
 CHA 
 
 Chalice, the cup used for the wine at 
 the celebration of the Eucharist. 
 
 Chalinque, >a boat which is almost of 
 a square building, used in Italy. 
 
 Chalk, in geology, forms the higher 
 part of the series or group termed 
 cretaceous : it is composed of nearly 
 44 parts of carbonic acid and 56 
 parts of lime. 
 
 Chamber of a mine, the place where 
 the powder is fixed. 
 
 Chambers (Sir William), born in 
 Stockholm in 1725, was an emi- 
 nent architect of the reign of 
 George III. In the year 1768 was 
 instituted the Royal Academy, to 
 the establishment of which Cham- 
 bers was principally instrumental. 
 In 1775 he was appointed by the 
 Government to construct the mag- 
 nificent edifice of Somerset House, 
 which was commenced in the fol- 
 lowing year. Sir William Cham- 
 bers had social intimacy with Drs. 
 Johnson, Goldsmith, Burney, and 
 Garrick, and other literary men of 
 his day ; he published several ar- 
 chitectural works, among them the 
 celebrated work on the decorative 
 part of civil architecture, which 
 Mr. Joseph Gwilt has re-edited and 
 improved. Died in London 1796. 
 
 Chambers, according to Palladio, are 
 made either arched or with a flat 
 ceiling: if in the last way, the height 
 from the floor to the joist above 
 ought to be equal to their breadth ; 
 and the chambers of the second 
 story must be a sixth part less than 
 them in height. 
 
 Chambranle, an ornament in masonry 
 and joiners' work which borders 
 the sides of doors, windows, and 
 chimneys. 
 
 Chandry, an apartment in a prince's 
 house, where the candles and other 
 lights are kept. 
 
 Chamfer. An edge or arris, taken off 
 equally on the two sides which form 
 it, leaves what is called a chamfer, 
 or a chamfered edge. If the arris 
 be taken off more on one side than 
 the other, it is said to be splayed 
 or bevelled. 
 
 100 
 
 ^"Chamfering, the process of cutting the 
 edge or the end of anything bevel 
 or aslope. 
 Champ, the flat surface of a wall. 
 
 ^Champe, the field or ground on which 
 
 carving is raised. 
 
 Champ de Mars : in French history, 
 the public assemblies of the Franks 
 are said to have been held in an 
 open field, and in the month of 
 March ; whence the name. 
 Chancel, the choir or eastern part of 
 a church appropriated to the use of 
 those who officiate in the perform- 
 ance of the services, and separated 
 from the nave and other portions 
 in which the congregation assemble, 
 sometimes by a screen. 
 Channel, in hydrography, the deepest 
 part of a river, harbour, or strait, 
 which is most convenient for the 
 track of shipping ; also an arm of 
 the sea running between an island 
 and the main, or continent, as the 
 British Channel, etc. 
 
 'Channelling, in architecture, perpen- 
 dicular channels, or cavities, cut 
 along the shaft of a column or 
 pilaster. 
 
 Channels, broad pieces of plank bolted 
 edgewise to the outside of a vessel, 
 used for spreading the lower rig- 
 ging- 
 
 i Chant, Chanting. The word ' chant ' 
 is derived from the Latin Cantus, 
 which signifies singing ; a song, a 
 lune, or melody, the sound of a 
 trumpet, crowing of a cock (whence 
 this bird is called ' chanticleer ') : 
 it also signifies the frequent repe- 
 tition of the same thing. The word 
 chant is not confined to merely a 
 melody consisting of several notes ; 
 it may consist of one only : in this 
 case it is called, in church music, 
 ' intonation,' although in Gregorian 
 music the word intonation has a 
 somewhat different signification. 
 (See Gregorian Chant.} Hence 
 chanting is reciting in a musical 
 tone, and is peculiarly adapted to 
 a dignified utterance of the sublime 
 language of the Liturgy. Chant- 
 ing or intoning on a monotone, or 
 
CHA 
 
 CHAPEL. 
 
 CHE 
 
 single sound, is the simplest and 
 easiest method of reading and re- 
 sponding the various prayers, ex- 
 hortations, litanies, suffrages, Kyrie 
 eleisons, Allelujahs, Gloria Patri, 
 and the Amens, and is eminently 
 more dignified and solemn than 
 when there is neither elevation nor 
 depression of the voice at any one 
 termination. In chanting the 
 greater and lesser Canticles, the 
 Te Deum, Jubilate, Benedicite, 
 Benedictus, Athanasian Creed, Ve- 
 nite exultemus, Magnificat, Can- 
 tate Domino, Nunc dimittis, Deus 
 misereatur, as also the prose 
 Psalms, the chant may consist of 
 more than one tone, although it is 
 preferable to use a small number. 
 The method of chanting the Psalter 
 in the English church is different 
 from that adopted on the Conti- 
 nent, where it appears to be go- 
 verned by no rule; whereas the 
 Gregorian chant is governed en- 
 tirely by rule. 
 
 Chantlate, in building, a piece of 
 wood fastened near the ends of the 
 rafters, and projecting beyond the 
 wall, to support two or three rows 
 of tiles, so placed to hinder the 
 rain-water from trickling down the 
 sides of the walls. 
 
 Chantry, an ecclesiastical benefice or 
 endowment to provide for the 
 chanting of masses. 
 
 Chapel, a small building attached 
 anciently to various parts of large 
 churches or cathedrals, and sepa- 
 rately dedicated ; also a detached 
 building for divine service : in Eng- 
 land chapels are sometimes called 
 chapels of ease, built for the ac- 
 commodation of an increasing po- 
 pulation. 
 
 Chapelling, wearing a ship round, 
 when taken aback, without bracing 
 the head-yards. 
 
 Chapiter, the capital of a column. 
 
 Chaplet, in architecture, a small orna- 
 ment carved into round beads, etc. 
 
 Chapman (Admiral), born in the last 
 century, in Sweden, of English 
 descent. His naval architectural 
 
 101 
 
 works on men-of-war and mer- 
 chant-vessels are, as examples of 
 principles, to practice the most 
 eminent. The plates are drawn to 
 a large scale, both in English and 
 Swedish measurements. 
 
 Chaps, the two planes or flat parts of 
 a vice or pair of tongs or pliers, for 
 holding anything fast, and which 
 are generally roughed with teeth. 
 
 Chapter-house, an establishment for 
 Deans and Prebendaries of cathe- 
 drals and collegiate churches ; the 
 apartment or hall in which the 
 monks and canons of a monastic 
 establishment conduct their affairs 
 connected with ecclesiastical regu- 
 lations. 
 
 Char or Chare, to hew, to work 
 charred stone; hewn stone. 
 
 Character, in a picture, is giving to 
 the different objects their appro- 
 priate and distinguishing appear- 
 ance. 
 
 Charcoal consists mainly of carbon 
 procured from the decomposition 
 of wood by burning. This ope- 
 ration is generally conducted in 
 pits made in the ground, and in 
 iron cylinders. Wood is essentially 
 composed of carbon, oxygen, and 
 hydrogen. Charcoal has the same 
 pr<0|)erties : it is black, lighter than 
 water, and full of pores, occasioned 
 by the expulsion of the bodies vo- 
 latilized. 
 
 Charge, in electricity, is the accumu- 
 lation of the electric matter on one 
 surface of an electric, as a pane of 
 glass, Leyden phial, etc., whilst an 
 equal quantity passes off from the 
 opposite surface. 
 
 Charge, in mining : any quantity of 
 ore put at one time into a furnace 
 to fuse is called a ' charge ;' letting 
 it out is called ' tapping.' 
 
 Chargers, large dishes, sometimes de- 
 scribed as ' flat pieces.' 
 
 Chdtelet, the common gaol and ses- 
 sion-house in the city of Paris. 
 
 Cheeks, the shears orbed of the lathe 
 as made with two pieces for con- 
 ducting the puppets. 
 
 Cheeks, the projection on each side 
 
CHE 
 
 CHEMISTRY. 
 
 CHE 
 
 of a mast, upon which the trestle- 
 trees rest ; the sides of the sheet* 
 of a block. 
 
 Cheeks. Two upright, equal and si- 
 milar parts of any piece of timber 
 work, as the sides of a dormer- 
 window. 
 
 Cheeks (of a mortise) are the two 
 solid parts upon the sides of the 
 mortise. The thickness of each 
 cheek should not be less than the 
 thickness of the mortise, except 
 mouldings on the stiles require it 
 to be otherwise. 
 
 Cheerly, quickly ; with a will. 
 
 Chemistry. The science of chemistry 
 has for its object the study of the 
 nature and properties of the dif- 
 ferent substances of which the 
 earth, the waters, the air, and their 
 inhabitants (namely, plants and 
 animals), are composed. In a 
 word, it embraces the study of 
 Everything under heaven accessible 
 to man. In its highest branches 
 it aims at discovering the laws or 
 rules which regulate the formation 
 of chemical compounds generally ; 
 and in its useful applications it has 
 been already exceedingly service- 
 able in directing and improving 
 the various arts of common life, as 
 agriculture, the working of mftals, 
 dyeing, and many other pursuits. 
 It serves also to guide the medical 
 man in the preparation of his re- 
 medies, and also occasionally in 
 distinguishing between diseases 
 which are in other respects much 
 alike. There is, indeed, scarcely a 
 situation in life in which a know- 
 ledge of chemistry may not prove 
 directly useful. It is a science the 
 study of which, from its simplest 
 beginnings to its highest attempts, 
 is rendered delightful by the con- 
 stant succession of new and inter- 
 esting things brought before the 
 eye and the mind. 
 
 Cherry-tree, a hard, close-grained 
 wood, of a pale red-brown colour : 
 when stained with lime, and oiled 
 and varnished, it resembles maho- 
 gany, and is used for furniture, etc. 
 
 102 
 
 Chess-trees, pieces of oak fitted to 
 the sides of a vessel, abaft the fore- 
 chains, with a sheave in them, to 
 board the main-tack to ; not much 
 used. 
 
 Chest, a piece of furniture for the re- 
 ception of all kinds of goods, par- 
 ticularly household conveniences, 
 deposited therein for security, and 
 for plate ; placed also in churches, 
 for the keeping of the holy ves- 
 sels, vestments, etc. : the seaman's 
 chest contains all the personalities 
 of a sailor. 
 
 Coffers and chests were the 
 general repositories for articles of 
 every kind ; writings, apparel, food, 
 and even fuel, were kept within 
 them. Many of these chests which 
 were raised on feet to protect them 
 from damp and vermin, were beau- 
 tifully ornamented with carving 
 and other sumptuous enrichments. 
 Large trunks, in which clothes, 
 hangings, etc., were packed for 
 removal, were called ' Trussing 
 Chests :' they were substantially 
 made, and bound in every direction 
 with iron straps, wrought into fan- 
 ciful forms, and secured by locks 
 of artful and curious contrivance. 
 Two " standard chests " were de- 
 livered to the laundress of King 
 Henry VI1L; " the one to keep the 
 cleane stuff, and the other to keep 
 the stuff that had been occupied." 
 " In ivory coffers," says Grameo, 
 " I have stuffed my crowns ; in 
 cypress chests, my arras, counter- 
 points, etc." Cypress-wood was 
 selected for its rare properties of 
 neither rottingnor becomingworm- 
 eaten. 
 
 Chestnut wood is very durable, and 
 was formerly much used in house 
 carpentry and furniture. 
 
 Cheval defrise, a square or octagonal 
 beam of wood, from 6 to 9 feet in 
 length, and pierced by iron rods or 
 wooden pickets 6 feet long, which 
 are pointed at each end, and shod 
 with iron : the pickets are placed 
 6 inches asunder, and pass through 
 two opposite faces of the beam, in 
 
CHE 
 
 CHIMNEY-PIECES. 
 
 CHI 
 
 directions alternately at right an- 
 gles to each other, the cheval 
 resting on the ground at the lower 
 extremity of the pickets. 
 Chevet, the termination of a church 
 behind the high altar, when of a 
 semicircular or polygonal form. 
 'Chevron, a moulding of a zig-zag cha- 
 racter, of the Norman style parti- 
 cularly, but sometimes to be found 
 with the pointed arch. 
 Chiaro-oscuro, a drawing made in two 
 colours, black and white ; also the 
 art of advantageously distributing 
 the lights and shadows which ought 
 to appear in a picture, as well for 
 the repose and satisfaction of the 
 eye as for the effect of the whole 
 together. 
 Chief point (in do.) is the uppermost 
 
 part of an escutcheon. 
 Chiliad, an assemblage of several 
 things ranged by thousands ; ap- 
 plied also to tables of logarithms, 
 which were at first divided into 
 thousands. 
 
 Chiliaedron, a solid figure of a thou- 
 sand faces. 
 
 Chiliagon, in geometry, a regular 
 plane figure of a thousand sides 
 and angles. 
 
 Chimes, a set of bells tuned to the 
 modern musical scale, and struck 
 by hammers acted on by a pinned 
 cylinder, or barrel, which revolves 
 by means of clock-work : also ap- 
 plied to the music or tune pro- 
 duced by mechanical means from 
 the bells in a steeple, tower, or 
 common clock. 
 
 Chimney, in locomotive engines. The 
 chimney is regulated in size for 
 each engine so as to act in union 
 with the blast-pipe, to produce a 
 proper blast on the fire. This is 
 done by each exhaust of steam 
 from the cylinders creating a partial 
 vacuum in the chimney : hence a 
 rush of air takes place through the 
 fire and tubes to fill this vacuum ; 
 nd these successive rushes of air 
 blow the fire.' This vacuum ranges 
 from 2 to 8 inches of a water-gauge. 
 The mild blast produces the least 
 
 103 
 
 vacuum and the least consumption 
 of fuel. 
 
 Chimney-pieces. The Egyptians, the 
 Greeks, and the Romans, to whom 
 architecture is so much indebted 
 in other respects, living in warm 
 climates, where fires in the apart- 
 ments were seldom necessary, have 
 thrown hut little light on this 
 branch of the science. Palladio 
 only mentions two, which stood in 
 the middle of the rooms, and con- 
 sisted of columns, supporting archi- 
 traves, whereon were placed the 
 pyramids or funnels through which 
 the smoke was conveyed. Scamozzi 
 mentions only three in his time, 
 placed similarly. In England, Inigo 
 Jones designed some very elaborate 
 chimney-pieces. The size of the 
 chimney must depend upon the 
 dimensions of the room wherein it 
 is placed: the chimney should 
 always be situated so as to be im- 
 mediately seen by those who enter : 
 the middle of the side partition 
 wall is the best place in halls, sa- 
 loons, and other rooms of passage, 
 to which the principal entrances 
 are commonly in the middle of the 
 front or of the back wall; but 
 in drawing-rooms, dressing-rooms, 
 etc., the middle of the back wall 
 is the best situation ; the chimney 
 being then farthest removed from 
 the doors of communication. 
 Chinese architecture, a style peculiar 
 to China, where the material em- 
 ployed is principally wood. It is 
 a style not congenial to English 
 taste or climate : its monstrosity 
 may be seen at Brighton. 
 Chinese Yellow (colour), a very bright 
 sulphuret of arsenic, brought from 
 China. 
 Chinse, to thrust oakum into seams 
 
 with a small iron. 
 
 Chisel, a tool with the lower part in 
 the form of a wedge, for cutting 
 iron plate or bar, and with the 
 upper part flat, to receive the blows 
 of a hammer, in order to force the 
 cutting edge through the substance 
 of the iron. 
 
CHI 
 
 CHISELS. 
 
 CHI 
 
 Chisel, an instrument used by car- 
 penters. The large chisels used by, 
 millwrights for heavy work are 
 generally composed of iron and 
 steel welded together. Chisels are 
 also employed in turning, and they 
 are driven more or less by blows : 
 those used by the joiners are similar; 
 but those used by cabinet-makers 
 are straight across the end. 
 
 Chisels in general. A chisel is an 
 edge tool for cutting wood, either 
 by leaning on it or by striking it 
 with a mallet. The lower part of the 
 chisel is the frustrum of a cuneus 
 or wedge ; the cutting edge is al- 
 ways on and generally at right 
 angles to the side. The basil is 
 ground entirely from one side. 
 The two sides taper in a small de- 
 gree upwards, but the two narrow 
 surfaces taper downwards in a 
 greater degree. The upper part of 
 the iron has a shoulder, which is a 
 plane surface at right angles to the 
 middle line of the chisel. From 
 this plane surface rises a prong in 
 the form of a square pyramid, the 
 middle line of which is the same as 
 the middle line of the cuneus or 
 wedge : the prong is inserted and 
 fixed in a socket of a piece of wood 
 of the same form : this piece of 
 wood is called the handle, and is 
 generally the frustrum of an octa- 
 gonal pyramid, the middle line of 
 which is the same as that of the 
 chisel : the tapering sides of the 
 handle diminish downwards, and 
 terminate upwards in an octagonal 
 dome. The use of the shoulder is 
 for preventing the prong from split- 
 ting the handle while being struck 
 with the mallet. The chisel is 
 made stronger from the cutting 
 edge to the shoulder, as it is some- 
 times used as a lever, the prop 
 being at or very near the middle, 
 the power at the handle, and the 
 resistance at the cutting-edge. 
 Some chisels are made with iron 
 on one side and steel on the other, 
 and others consist entirely of steel. 
 There are several kinds of chisels, 
 
 104 
 
 as the mortise-chisel, the ripping- 
 chisel, and the socket-chisel. 
 
 Chisel, the firmer, is formed in the 
 lower part similar to the socket- 
 chisel ; but each of the edges above 
 the prismoidal part falls into an 
 equal concavity, and diminishes 
 upwards until the substance of the 
 metal between the concave narrow 
 surfaces becomes equal in thickness 
 to the substance of that between 
 the other two sides, produced in a 
 straight line, and meeting a protu- 
 berance projecting equally on each 
 side. The firmer chisel is used by 
 carpenters and joiners in cutting 
 away the superfluous wood by thin 
 chips : the best are made of cast 
 steel. When there is a great deal 
 of superfluous wood to be cut away, 
 sometimes a stronger chisel, con- 
 sisting of an iron back and steel 
 face, is first used, by driving it into 
 the wood with a mallet ; and then 
 a slighter one, consisting entirely of 
 steel sharpened to a very fine edge, 
 is used in the finish. The first 
 used is called a firmer, and the last 
 a paring chisel, in the application of 
 which only the shoulder or hand is 
 employed in forcing it into the wood. 
 
 Chisel, the mortise, is made exceed- 
 ingly strong, for cutting out a 
 rectangular prismatic cavity across 
 the fibres, quite through or very 
 deep in a piece of wood, for the 
 purpose of inserting a rectangular 
 pin of the same form on the end of 
 another piece, and thereby uniting 
 the two. The cavity is called a 
 mortise, and the pin inserted a 
 tenon ; and the chisel used for cut- 
 ting out the cavity is, therefore, 
 called a mortise-chisel. As the 
 thickness of this chisel from the 
 face to the back is great, in order 
 to withstand the percussive force 
 of the mallet, and as the angle 
 which the basil makes .with the 
 face is about 25, the slant dimen- 
 sion of the basil is very great. This 
 chisel is only used by percussive 
 force given by the mallet. 
 
 Chisel, the ripping, is only an old 
 
CHI 
 
 CHORAGIC MONUMENTS. 
 
 CHR 
 
 socket-chisel used in cutting holes 
 in walls for inserting plugs, and for 
 separating wood that has been 
 nailed together, etc. 
 
 Chisel, the socket, is used for cutting 
 excavations : the lower part is a 
 prisraoid, the sides of which taper 
 in a small degree upwards, and the 
 edges considerably down wards: one 
 side consists of steel, and the other 
 of iron. The under end is ground 
 into the form of a wedge, forming 
 the basil on the iron side, and the 
 cutting edge on the lower end of 
 the steel face. From the upper end 
 of the prismoidal part rises the 
 frustrum of a hollow cone, in- 
 creasing in diameter upwards : the 
 cavity or socket contains a handle 
 of wood of the same conic form : 
 the axis of the handle, the hollow 
 cone, and the middle line of the 
 frustrum, are all in the same straight 
 line. The socket-chisel, which is 
 commonly about 1^ or 1^ inch 
 broad, is chiefly used in cutting 
 mortises, and may be said to be the 
 same as the mortise-chisel em- 
 ployed in joinery. 
 
 Chisel, in turnery, a flat tool, skewed 
 in a small degree at the end, and 
 bevelled from each side, so as to 
 make the cutting edge in the 
 middle of its thickness. 
 
 Chock, in navigation, a wedge used to 
 secure anything with, or for any- 
 thing to rest upon. The long-boat 
 rests upon two large chocks when 
 it is stowed. 
 
 Chocolate lead, a pigment prepared 
 by calcinating oxide of lead with 
 about a third of that of copper, 
 and reducing the compound to a 
 uniform tint by levigation. 
 
 Choke. An adit is said to be choked 
 when any earth or stone falls in 
 and prevents the current of water 
 through it : the place or part so 
 filled is called ' the choke.' 
 
 Chopping -block, a block of wood used 
 for reducing bricks to their intended 
 form by axing them : it is made of 
 any chance piece that can be ob- 
 tained, and commonly from 6 to 8 
 
 inches square, supported generally 
 upon two 14 -inch brick piers, if two 
 men are to work at it ; but if four 
 men, the chopping-block must be 
 lengthened and supported by three 
 piers, and so on, according to the 
 number : it is about 2 feet 3 inches 
 in height. 
 
 Choragic monuments, in Grecian story, 
 monuments in honour of those 
 who had gained a prize as choragus, 
 or leader of the play and choruses. 
 
 Choragic monument of Lysicrates, 
 known as the Lantern of De- 
 mosthenes, was built in the lllth 
 Olympiad, and is still entire : it is 
 considered the most exquisite and 
 perfect specimen of the orders. 
 
 Choragic monument of Thrasycles, 
 etc., now the church of our Lady of 
 the Grotto. It is built against the 
 rock of the Acropolis : above it 
 stand two columns, on which tripods 
 have been placed, and on each side 
 of it the rock has been chiseled 
 away in such form as evidently 
 shows that similar buildings had 
 been erected contiguous to it. 
 
 Chord, in geometry, is the right line 
 joining the extremities of any arc 
 of a circle. 
 
 Chorobates (Greek), an instrument 
 for determining the slope of an 
 aqueduct, and the levels of the 
 country through which it was to 
 pass. It differed but slightly from 
 a common carpenter's level, which 
 consists of a straight rule support- 
 ing a perpendicular piece, against 
 which hangs a plumb-line. 
 
 Chorography,i}\e&ri of making a map 
 of a particular country or province, 
 or of teaching geography. 
 
 Chromatics, a division of the science 
 of optics, by which the properties 
 of the colours of light and of 
 natural bodies are illustrated. 
 
 Chromaseape, or optical chromatics : 
 there are three species of optical 
 effects of colours, that of refrac- 
 tion of prisms and lenses, that of 
 the transmission of light through 
 transparent media, and that of the 
 reflection of specula, etc. 
 
 105 
 
 F 3 
 
:HR 
 
 CHRONOMETRICAL GOVERNOR. 
 
 CHU 
 
 Chromate of mercury is improperly . 
 classed as a red with vermillion ; 
 for though it is of a bright ochreous 
 red colour in powder, it is, when 
 ground, of a bright orange ochre 
 hue, and affords, with white, very 
 pure orange-culoured tints. 
 Chromatics, the science of the rela- 
 tions of light, shade, and colours. 
 Chrome greens are compound pig- 
 ments of which chrome yellow is 
 the principal colouring substance. 
 Chrome orange is a beautiful orange 
 pigment,andoneof the mostdurable 
 and least exceptionable chromates 
 of lead, but not of iron. 
 Chrome yellow is a pigment of modern 
 introduction into general use, and 
 of which there are many varieties, 
 mostly chromates of lead, in which 
 the latter metal more or less 
 abounds. They are distinguished by 
 the pureness, beauty, and brilliancy 
 of their colours, which qualities 
 are great temptations to their use 
 in the hands of the painter ; they 
 are, however, far from unexception- 
 able pigments. 
 
 Chromium, a very rare metal, found 
 either in the form of chromate of 
 lead or chromate of iron. 
 Chronometer, a time-keeper, used for 
 determining the longitude at sea, 
 and for other purposes where great 
 accuracy is required. 
 Chronometrical governor, an improved 
 regulator for rendering the mean 
 velocity of an engine uniform. The 
 mechanism is as follows : a spindle 
 placed vertically has a pulley fixed 
 upon the top, to receive motionfrom 
 the crank-shaft ; below the pulley 
 two bevel'wheels of equal diameters 
 are placed face to face ; the upper 
 wheel is fixed to the spindle, and 
 the lower one is free to turn upon 
 it, and has an arm or crank attached 
 to its under side, to act as a driver 
 for the pendulous ball : between the 
 two wheels, and communicating 
 with them, is a third wheel, fixed 
 upon a spindle placed horizontally, 
 and connected at one end with the 
 vertical spindle, so as to turn round 
 
 106 
 
 it ; the other end is supported by a 
 carnage resting upon a plate, and 
 is connected with a spring or coun- 
 ter weight on one side, and on the 
 other side with the throttle-valve ; 
 the ball being suspended from a 
 sperical bearing near the top of 
 the rod. The spring is adjusted 
 so that when the velocity of the 
 engine is as required, the upper and 
 lower wheels revolve at the same 
 speed : when the velocity increases, 
 the centrifugal force causes the ball 
 to rise, and retards the motion of 
 the lower wheel ; then the inter- 
 mediate wheel distends the spring, 
 and moves forward upon the lower 
 wheel as a rack, and closes the 
 throttle-valve : when the velocity 
 diminishes, the ball falls, and the 
 lower wheel requires less power, so 
 that the spring pulls back the inter- 
 mediate wheel and opens the valve. 
 The above is a modification of Mr. 
 James Wood's governor, and is 
 patented by Mr. C. W. Siemans. 
 
 Chrysolite, a precious stone, probably 
 the tenth on the high-priest's pec- 
 toral, bearing the name of Zebulon : 
 it is transparent, the colour of gold, 
 with a mixture of green, which dis- 
 plays a fine lustre. 
 
 Chuck, a piece of wood or metal fixed 
 on the end of the mandril for keep- 
 ing fast the body to be turned. 
 
 Church Music. By this term is com- 
 monly understood all music set to 
 words of a sacred character : hence 
 we have not only the language of 
 Scripture set to music in the shape 
 of anthems, etc., but also metrical 
 versions and paraphrases thereof, 
 used and considered by many as 
 church music. Indeed it too often 
 happens that these are adapted to 
 secular melodies melodies not ori- 
 ginally intended to be applied to 
 words of a sacred character, and yet 
 the music is then termed sacred, 
 probably from an idea that there is 
 no such thing as sacred and profane 
 music. But this is a great error 
 and arises solely from ignorance o: 
 the existence of sacred music, we 
 
CHU 
 
 CHURCH MUSIC. 
 
 CHU 
 
 mean especially church music. Ex- 
 amine any of the ancient authorized 
 liturgical books, and there will be 
 found an order of music that can- 
 not be mistaken for profane, which 
 is not only sacred in its character, 
 but eminently grand, dignified, 
 noble, and sublime ; in short, it is 
 for church purposes so superior to 
 all other music, that it alone can 
 properly be called church music. 
 
 Church music is the music of the 
 holy offices, is that music in which 
 ihewholechtirch,priests and people, 
 can participate. It is easy to exe- 
 cute, being simple and plain (plain 
 chant). It can be sung by every 
 one, and is always most majestic 
 when sung by all ; hence it is also 
 called the full chant (cantus ple- 
 nus). For a long period, and until 
 very lately, scarcely a remnant of 
 church music was to be found, even 
 in those places where we had a 
 right to expect to find it : the plain 
 chant was banished entirely in some 
 places, and mutilated in others, so 
 that it could scarcely be discerned ; 
 but it is now being restored, and 
 we hear the priest intoning his part 
 in the offices of morning and evening 
 prayer, and the people singing, in 
 response, the ancient authorized 
 melodies of the church ; we hear 
 the Psalter chanted to fine old (so 
 called) Gregorian tones ; we hear 
 the Litany chanted to its own proper 
 music, that of the church : we also 
 hear the soul-stirring music in the 
 Communion office, the Gloria in ex- 
 celsis, the Credo, and Sanctus ; the 
 latter moreover in its proper place. 
 We can have also, if so disposed, 
 the church music for the matri- 
 monial,baptismal, and burial offices, 
 as well as an immense variety of 
 tunes for the metrical psalms, of a 
 true church character, unlike any 
 other kind of music, and which is 
 truly church music, inasmuch as it 
 is the church's peculiar property, 
 and would be totally misused in 
 any other place. Our definition of 
 church music is, music which is 
 
 107 
 
 adapted for the services and pur- 
 poses of the church, and unfit for 
 any other place or purpose. 
 
 Church music, such as is here 
 shortly defined, is unisonous; and 
 harmonized music is not fit for 
 congregational purposes ; it is pro- 
 per only in those parts of divine 
 worship which may be called extra- 
 liturgical, such as the anthem. 
 Singing harmonized chants, canti- 
 cles, Te Deum, etc., is thrusting out 
 the congregation, that is, the chief 
 part of the church present. The 
 harmonies should be left entirely 
 to the discretion of an intelligent 
 organist, to be executed on the 
 organ alone. Harmonized music 
 requires accomplished and well- 
 informed musicians for its perform- 
 ance, and can be sung only by the 
 few. The anthem, in cathedral 
 worship, is edifying only when it is 
 performed by the choir-men in a 
 masterly manner, not only with 
 correct musical execution, but with 
 care and attention, to develop all 
 the piety, sublimity, grandeur, dig- 
 nity, and whatever else the music 
 is capable of. 
 
 Before the latter half of the 15th 
 century, the liturgy was chanted in 
 unison ; and it is from this period 
 we can trace the gradual departure 
 from the rigid church style of mu- 
 sic, in the compositions of Josquin 
 de Pres especially. In the early 
 part of the 16th century, we find 
 that Adrian Willaert, who was 
 made singing-master at St. Mark's, 
 Venice, was the first who harmo- 
 nized the psalm melodies for two or 
 more choirs ; then followed the mo- 
 tet, or harmonized antiphon, which 
 before had been chanted in unison, 
 as it is done at this day in the Ro- 
 man Catholic chapels in England, 
 where there are not accomplished 
 singing men to perform the motet. 
 During this century, the use of 
 harmony had not only driven the 
 people away from their part in the 
 performance of ths service, but 
 also corrupted the music itself so 
 
CHU 
 
 CINQUE-CENTO. 
 
 CIR 
 
 much, that it was only saved from 
 being wholly forbidden by the 
 grave and devotional motets and 
 other compositions of the renown- 
 ed Palestrina, whose works were 
 imitated with great success by the 
 disciples of his school, and this in 
 a very eminent degree by the Eng- 
 glish church musicians. The har- 
 monies used by Tallis, Morley, 
 Gibbons, and the rest of the mas- 
 ters of church music of this age, 
 are truly sublime. 
 
 Church ornament consists principally 
 of the painted and stained glass 
 windows of the emblem of the 
 Trinity, of the passion of our Lord, 
 of the evangelists, sacred mono- 
 grams, statues of the holy apostles, 
 of the holy evangelists, and of 
 the saints commemorated by the 
 church. 
 
 Church in rotunda, that whose plan 
 is a perfect circle, in imitation of 
 the Pantheon. 
 Chymol, a hinge, anciently called a 
 
 grimmer. 
 Ciborium, an arch supported by four 
 
 pillars placed over the high altar. 
 I Cilery, in architecture, the drapery 
 or leavage that is wrought upon 
 the head of pillars. 
 Cill, the timber or stone at the foot. 
 Ground-cills are the timbers on 
 the ground which support the posts 
 and superstructure. 
 Cimellare, the vestry or roam where 
 plate, vestments, and other rich 
 things belonging to the church are 
 kept. 
 
 ! Cincture, a ring, list, or fillet at the 
 top and bottom of a column, serv- 
 ing to divide the shaft from the 
 capital and its base. 
 Cinder-frame, in locomotive engines, 
 a wire-work frame placed in front 
 of the tubes, to arrest the ascent 
 of large pieces of ignited coke. 
 Cinque-cento, a term generally archi- 
 tecturally applied to the Revival of 
 art, co-eval with the early Tudor 
 style in England and the Renais- 
 sance style in France. In 1506 
 the church of St. Peter's at Rome 
 
 108 
 
 was commenced by Bramante, the 
 greatest monument of the revived 
 classical or Cinque-cento style of 
 architecture, and on the death of 
 Bramante, in 1514, the great Raf- 
 faello continued the building. The 
 Loggia Vaticano is a monument of 
 his fame for its design and orna- 
 mentation. 
 
 Cinque-cento, literally five hundred, 
 or the fifth Century, generally ap- 
 plied to the period of the Revival 
 of the arts in Italy and even sub- 
 sequently. The ornament was of 
 an enriched kind, much applied by 
 the Italians, and since by the French. 
 ^Cinque-foil, an ornamental foliation 
 or feathering, used in the arches 
 of the lights and tracery of wind- 
 dows, panellings, etc. 
 Cinque Ports, the sea-port towns of 
 Dover, Sandwich, Hastings, Hythe, 
 and Romney, to which three others 
 were afterwards added, viz. Win- 
 chelsea, Rye, and Seaford. These 
 towns possess peculiar privileges, 
 and are under the government of a 
 Lord Warden. 
 
 Cipher, a secret mode of writing. 
 Cipollino, is a name given by the Ita- 
 lians to an impure marble, which 
 containing veins of schistose, de- 
 composes and falls off in flakes like 
 the coats of an onion. 
 Cippus (Latin), a low column, some- 
 times round, but more frequently 
 rectangular, used as a sepulchral 
 monument. 
 
 Circinus, a pair of compasses. Those 
 used by statuaries, architects, ma- 
 sons, carpenters, etc., were often 
 represented on their tombs. 
 Circinus, according to Vitruvius, a 
 pair of compasses employed by 
 architects, carpenters, etc., for de- 
 scribing circles, measuring dis- 
 tances, and taking the thickness of 
 solids. 
 
 Circle, a plain figure contained by 
 one line, which is called the cir- 
 cumference, and is such that all 
 straight lines drawn from a certain 
 point within the figure to the cir- 
 cumference are equal to one an- 
 
CIR 
 
 CIRCULAR. 
 
 CLA 
 
 other, and this point is called the 
 centre of the circle. 
 
 The circumference of a circle is 
 known to be about 3' 141 59 times 
 its diameter," or, in other words, 
 the ratio of the circumference to 
 the diameter is represented by 
 3*14159 : for this number writers 
 generally put the Greek letter IT. 
 
 Circular sailing, is that which is 
 performed in the arch of a great 
 circle. 
 
 'Circular saw. Circular saws, revolv- 
 ing upon an axis, have the advan- 
 tage that they act continually in 
 the same direction, and no force is 
 lost by a backward stroke : they 
 are also susceptible of much greater 
 velocity than the reciprocating 
 saws, an advantage which enables 
 them to cut more smoothly : used 
 principally for cutting mahogany 
 for veneering, and for other woods 
 cut into thin layers. 
 
 Circus, an area used by the Romans 
 for chariot-races and horse-races, 
 and for other public sports. 
 
 Cissoid of Diocles, in the higher geo- 
 metry, a curve line of the second 
 order. 
 
 Cistern. There were cisterns through- 
 out Palestine, in cities and in pri- 
 vate houses. As the cities were 
 mostly built on mountains, and the 
 rains fall in Judea at two seasons 
 only (spring and autumn), people 
 were obliged to keep water in ves- 
 sels. There are cisterns of very 
 large dimensions at this day in Pa- 
 lestine. Near Bethlehem are the 
 cisterns or pools of Solomon : they 
 are three in number, situated in 
 the sloping hollow of a mountain, 
 one above another, so that the 
 waters of the uppermost descend 
 into the second, and those of the 
 second descend into the third. 
 The breadth is nearly the same in 
 all, between 80 and 90 paces, but 
 the length varies : the first is about 
 160 paces long; the second, 200 ; 
 the third, 220. These pools for- 
 merly supplied the town of Beth- 
 lehem and the city of Jerusalem 
 
 109 
 
 with water. Wells and cisterns, 
 fountains and springs, are seldom 
 correctly described in Scripture. 
 
 Cistern, in the steam-engine, the 
 vessel which surrounds the con- 
 denser, and contains the injection 
 water. 
 
 Cisterna, an artificial tank or reser- 
 voir, sunk in the ground and co- 
 vered in with a roof, for the pur- 
 pose of collecting and preserving 
 good water for the use of a house- 
 hold. Near the baths of Titus are 
 nine subterraneous cisterns, 17i 
 feet wide, 12 feet high, and above 
 137 feet long. 
 
 Citrine, or the colour of the citron, 
 is the first of the tertiary class of 
 colours, or ultimate compounds of 
 the primary triad, yellow, red, and 
 blue, in which yellow is the archeus 
 or predominating colour, and blue 
 the extreme subordinate ; for ci- 
 trine being an immediate compound 
 of the secondaries, orange and 
 green, of both which yellow is a 
 constituent, the latter colour is of 
 double occurrence therein, while 
 the other two primaries enter singly 
 into the composition of citrine ; 
 its mean or middle hue compre- 
 hending eight blue, five red, and 
 six yellow, of equal intensities. 
 
 Citrine lake is a durable and better 
 drying species of brown pink, pre- 
 pared from the quercitron bark. 
 
 City, a town, an incorporated town, 
 a town having had a bishop's see. 
 
 Clack, the valve of a pump piston; 
 the can-lead, in Derbyshire. 
 
 Clacks, in locomotive engines, the 
 complete valves of the pumps where 
 the ball-valve is enclosed in a 
 frame or cage, to limit its rise, and 
 guide its fall into the steam-tight 
 seat of the orifice of the pipe. 
 
 Clack-box, in locomotive engines, the 
 box fitted on to the boiler where 
 a ball-clack is placed, to close the 
 orifice of the feed-pipe, and pre- 
 vent steam or hot water reaching 
 the pumps. The ball of the clack 
 is raised from its seat by the stroke 
 of the pump-plunger forcing the 
 
CLA 
 
 CLASSIC ORDERS. 
 
 CLI 
 
 water against it, which water then 
 passes into the boiler, while the 
 instant fall of the ball prevents 
 egress from the boiler. 
 
 Clack-door, a square iron-plate screw- 
 ed on to the side of a bottom-pump, 
 or small bore for convenience of 
 changing the clack or valve. 
 
 Clack-seats, in locomotive engines, 
 two recesses in each pump, for the 
 clacks to fit into. 
 
 Clack-valve, in the steam-engine, a 
 flat valve in the cold-water pump, 
 with a hinge joint. 
 
 Clamp, a kiln built above the ground, 
 for the purpose of burning bricks 
 in: 
 
 Clamp, a piece of wood fixed to the 
 end of a board by mortise and 
 tenon, or by groove and tongue, 
 so that the fibres of the one piece, 
 thus fixed, traverse those of the 
 board, and by this means prevent 
 it from casting : the piece at the 
 end is called a clamp, and the board 
 is said to be clamped. 
 
 Clamps, in naval architecture, thick 
 planks in a ship's side, which sup- 
 port the ends of the beams. 
 
 Clamping, in joinery : when a piece 
 of board is fitted with the grain to 
 the end of another piece of board 
 across the grain, the first board is 
 said to be clamped. 
 
 Clamp-nails, used to fasten on clamps 
 in the building of ships. 
 
 Clasp-nails, are such with heads, 
 brought into a little compass, so 
 that they will sink into the wood. 
 
 Classic Orders, in architecture : of 
 these there are but three, the 
 Doric, Ionic, and Corinthian : two 
 others, the Tuscan and Composite, 
 are often improperly classed with 
 them, and the whole denominated 
 ' the five orders of architecture.' 
 
 Claude Roman, architect of Paris ; 
 he designed and executed the grand 
 altar, and, in consideration of the 
 merit of that work, was permitted 
 to be buried before the image of 
 the Virgin, which he had chosen 
 for the place of his interment ; he 
 died in 1675, aged 65. 
 
 110 
 
 Claustura, brushwood for fences and 
 hedges. 
 
 Cleading, in locomotive engines, is 
 usually made of narrow strips of 
 timber, neatly fitted round the 
 boiler and fire-box, to prevent the 
 radiation of the heat. Externally, 
 this is sometimes covered with 
 zinc, and a coating of dry hair felt 
 is commonly placed between the 
 boiler and the timber, for the same 
 purpose. 
 
 Clear, in architecture, inside work. 
 
 Clearing the deads, a term for clearing 
 a shaft or drift, etc. 
 
 Cleat, a piece of wood used in different 
 parts of a vessel to belay ropes to. 
 
 Cleavage, in geology, is an indicator 
 of peculiar fossility in certain 
 rocks, which is independent of, 
 and meets at a considerable angle, 
 the surfaces of lamination or de- 
 position. Clay slate furnishes the 
 best examples of this phenomenon. 
 
 Cleithral, a covered Greek temple. 
 
 Cleithros, an enclosed place ; a temple 
 whose roof covers or encloses it. 
 
 Clench-dolts, in a ship, clenched at 
 the ends where they come through. 
 
 Clench-nails, are such as will drive 
 without splitting the board, and 
 draw without breaking. 
 
 Clepsydra, an instrument anciently 
 used by the Egyptians to measure 
 time by the running of water out 
 of one vessel into another ; which 
 we call an hour-glass. 
 
 Clerestory, an upper story or row of 
 windows in a Gothic church, rising 
 clear above the adjoining parts of 
 the building. 
 
 Clew, the lower corner of square- 
 sails, and the after corner of a fore- 
 and-aft sail. 
 
 Clew-garnet, a rope for hauling up 
 the clew of a fore-sail or main- 
 sail in a square-rigged vessel. 
 
 Clew-line, a rope for hauling up the 
 clew of a square-sail : the clew- 
 garnite is the clew-line of a course. 
 
 Clicket, a latch-key ; the latch of a 
 door. 
 
 Clinch, in navigation, the great ring 
 connected with themooring-chains. 
 
COAL. 
 
 COA 
 
 Clinch, a. half-hitch stopped to its 
 
 own part. 
 
 Clinker-bar, in steam-engines, the bar 
 fixed across the top of the ash-pit 
 for supporting the rods used for 
 clearing the fire-bars. 
 
 Clinkers, bricks which, by the vio- 
 lence of the fire, are run together 
 and glazed over ; hard bricks im- 
 ported from Holland, so called. 
 
 Cloaca, a common sewer. The term 
 cloaca is generally used in reference 
 to those spacious subterraneous 
 vaults, either of stone or brick, 
 through which the foul waters of 
 the city, as well as all the streams 
 brought to Rome by the aque- 
 ducts, finally discharged themselves 
 into the Tiber ; according to Livy, 
 a large subterranean canal, con- 
 structed of masonry or brick-work, 
 for the purpose of carrying off the 
 rain-water from the streets of a 
 town, and the impurities from 
 private houses, which were thus 
 discharged into some neighbouring 
 river. 
 
 Cloacarium, the sewers-rate ; a tax 
 which was levied in Home for the 
 expenses of cleansing and repair- 
 ing the sewers. 
 
 Cloister, a covered ambulatory, form- 
 ing part of a monastic or collegiate 
 establishment. Cloisters are always 
 attached to a college cathedral, 
 and arranged round three or four 
 sides of a quadrangular area, with 
 large windows, not often glazed, 
 looking into the quadrangle. 
 
 Close-hauled, a term applied to a ves- 
 sel sailing with her yards braced 
 up so as to get as much as possible 
 to windward. 
 
 Closer, a brick-back inserted where 
 the distance will not permit of a 
 brick in length. 
 
 Closet, a small chamber or private 
 room. 
 
 Clout-nails, used for nailing clouts on 
 the axle-trees of the carriage. 
 
 Clove-hitch, two half-hitches round a 
 spar or other rope. 
 
 Clove-hook, an iron clasp, in two 
 parts, moving upon the same pivot 
 
 111 
 
 and overlapping one another, used 
 for bending chain-sheets to the 
 clews of sails. 
 
 Clubbing, drifting down a current 
 with an anchor out. 
 
 Club-haul, to bring a vessel's head 
 round on the other tack, by letting 
 go the lee anchor, and cutting or 
 slipping the cable. 
 
 Clue garnets, in navigation, tackles 
 fixed to the clews or lower corners 
 of the fore and main sail, to clew 
 them up to the yards. 
 
 Clustered column, a pier which con- 
 sists of several columns or shafts 
 clustered together. 
 
 Clutch, an apparatus for engaging or 
 disengaging two shafts : it consists 
 of two pieces of metal formed so 
 that when placed together, project- 
 ing pieces on one (made to slide 
 to and fro on the shaft, but turn 
 with it) fit into recesses in the 
 other, which is fixed on the driving 
 shaft, so that the first being pulled 
 back, its shaft will remain at rest. 
 
 Coaking, in ship-building, uniting 
 pieces of spar by means of tabular 
 projections, formed by cutting 
 away the solid of one piece into 
 a hollow, so as to make a projection 
 in the other in such a manner that 
 they may correctly fit, the buts pre- 
 venting the pieces from drawing 
 asunder. 
 
 Coal belongs to the third series of 
 the Wernerian principle, viz. car- 
 boniferous rocks, coal-measures, 
 carboniferous limestone, and old 
 red sandstone ; it is admitted to be 
 of vegetable origin, and comprises 
 1. Lignites, a species of mineral 
 charcoal or intermediate gradation 
 from wood to coal ; 2. Ordinary 
 bituminous coal, of numerous va- 
 rieties ; 3. Anthracite, found gene- 
 rally in connection with the lowest 
 portion of the third series, and 
 sometimes in the primary rocks 
 themselves. Coal, then, appears to 
 have been formed of large vegetable 
 masses, of considerable extent, in 
 strata varying from a few inches 
 to many feet in depth, the strata 
 
COA 
 
 COBALT. 
 
 COC 
 
 alternating with rocks wonder- 
 fully uniform, and consisting, in* 
 most cases, of the following : sand- 
 stone, slate clay or shale, fire-clay, 
 ironstone, limestone, etc. Rocks 
 are found participating of both 
 clay and sandstone texture, greatly 
 predominating. The coal-beds are 
 indiscriminately accompanied by 
 rocks either of sandstone or shale, 
 which often rest upon fire-clay. It 
 is in the shale accompanying the 
 coal that the fossil impressions are 
 so numerous; they are seldom 
 found in the sandstones, or in the 
 shales considerably distant from 
 the coal-beds. The organic remains 
 of coal formation consist of many 
 shells of freshwater origin. The 
 fossils, with land plants, occur in 
 great abundance and variety, be- 
 longing to extinct species, but 
 bearing considerable analogy to 
 those now growing only in tropical 
 climates. These plants are mostly 
 succulent, and are of enormous 
 growth. 
 
 Coal-gas, carburetted hydrogen ; coal- 
 gas, when freed from the obnoxious 
 foreign gas, may be propelled in 
 streams out of small apertures, 
 which, when lighted, from jets of 
 flame, and are called gas-lights. 
 
 Coal-tar, tar made from bituminous 
 coal. 
 
 Coamings, in ships, raised work round 
 the hatches, to prevent water from 
 getting down into the hold. 
 
 Coat. Mast-coat is a piece of canvas 
 tarred or painted, placed round a 
 mast or bowsprit where it enters 
 the deck. 
 
 Coat, in building, a stratum or thick- 
 ness of plaster- work. 
 
 Cob (Cornish), to break or bruise: 
 a cobber, a bruiser of tin. Cobbed 
 ore is spoiled which is broken out 
 of the solid large stones with 
 sledges, and not put to water, 
 being the best ore: the same as 
 bing ore in the lead-mines. 
 
 Cobalt (among miners), the damps 
 of mines, so very fatal to the 
 workmen. 
 
 Cobalt. The ancient name for this 
 mineral is not known. Theophras- 
 tus mentions its use for staining 
 glass. No cobalt has been disco- 
 vered in any of the remains of 
 ancient painting. It makes a co- 
 lour, according to Vitruvius, be- 
 tween scarlet and purple. 
 
 In chemistry, a metal, when 
 pure, of a white colour, inclining 
 to bluish or steel gray : at the com- j 
 mon temperature its specific gra- 
 vity is more than 8'5. 
 
 Cobalt-blue is the name now appro- 
 priated to the modern improved 
 blue prepared with metallic cobalt, 
 or its oxides, although it properly 
 belongs to a class of pigments in- 
 cluding Saxon blue, Dutch ultra- 
 marine, Thenard's blue, royal blue, 
 Hungary blue, smalt, Zaffoe or 
 enamel blue, and Dumont's blue. 
 These differ principally in their 
 degrees of purity, from the nature 
 of the earths with which they are 
 compounded. 
 
 Cobalt-green. There are two pig- 
 ments of this denomination, the 
 one a compound of cobalt-blue and 
 chromic yellow, which partakes of 
 the qualities of those pigments, and 
 may be formed on the pallet. 
 
 Caboose, the place where the victuals 
 are cooked on board of merchant 
 and passenger ships. 
 
 Cob-wall, a wall built of unburnt clay 
 mixed with straw. 
 
 Cochineal is extremely rich in the 
 finest red colouring matter, and has 
 been long employed in scarlet dye- 
 ing, and in the manufacture of 
 carmine. 
 
 Cochlea, a term used by the ancients 
 to denote something of a spiral 
 form ; a spiral pump for raising 
 water, etc. 
 
 Cock, or stop-cock, a kind of valve 
 contrived for the purpose of per- 
 mitting or arresting at pleasure the 
 flow of a liquid through a pipe. 
 
 Cock-boat, a small boat used on rivers. 
 
 Cock-pit, that part of a ship which is 
 appropriated to the use of the sur- 
 geon, being the place where the 
 
COG 
 
 COHESION. 
 
 COH 
 
 wounded are dressed : it is near 
 the hatchway, and under the 
 lower gun-deck. 
 
 Cockle, the skiorl of the Swedes and 
 the schorl of the Germans : a la- 
 minated mineral substance of a 
 blackish brown colour, like tin. 
 
 Cocoa-wood, the heart of which is 
 seldom sound, is much used in 
 turnery. 
 
 Coctilis, according to Pliny, a brick 
 hardened by burning. 
 
 Cock-water (among miners), a stream 
 of water brought into a trough to 
 wash away the sand from tin-ore. 
 
 Cod-line, an eighteen-thread line. 
 
 Co-efficients, in algebra, are numbers 
 or letters prefixed to other letters 
 or unknown quantities, into which 
 they are supposed to be multiplied ; 
 and therefore with such letters, or 
 the quantities represented by them, 
 making a product, or co-efficient 
 product. 
 
 Coigne, a corner ; a wooden wedge. 
 
 Coining (in the tin works), is the 
 weighing and stamping the blocks 
 of tin. 
 
 Coelum, according to Vitruvius, a 
 soffit or ceiling. 
 
 Comobium, anciently a monastery of 
 monks or friars. 
 
 C6fer, in Cornish mining, a small 
 wooden trough which receives the 
 tin claused from its impurities or 
 slime. 
 
 Coffee-tree, a wood of a light greenish 
 brown, close-grained, and small in 
 stature, sometimes used by cabi- 
 net-makers. 
 
 Coffer, a deep panel in a ceiling; also 
 applied to a casket for keeping 
 jewels, and sometimes to a chest. 
 
 Coffer-dam, a hollow space formed 
 by a double range of piles, with 
 clay rammed in between, for the 
 purpose of constructing an en- 
 trance lock to a canal, dock, or 
 basin, or for the piers of a bridge. 
 
 Coffin, in Cornish mining, old work- 
 ings which were all worked open 
 to grass, without any shafts, by dig- 
 ging and casting up the thin stuff 
 from one stall of boards to another. 
 
 113 
 
 Coffin, a wooden case in which a 
 dead body is placed, sometimes en- 
 cased in lead : anciently, stone 
 coffins were used for interment. 
 
 Cog, the wooden tooth of a large 
 wheel. 
 
 Cog-teeth are formed of a different 
 material from the body of the 
 wheel : a timber tooth on a cog- 
 wheel is one made of wood, when 
 the teeth stand perpendicularly to 
 the plane of the wheel. 
 
 Cog-wheel, an iron wheel with wooden 
 teeth or cogs. 
 
 Cohesion of fluids. M. Monge and 
 others assert that the phenomena 
 of capillary tubes are referable to 
 the cohesive attraction of the su- 
 perficial particles only of the fluids 
 employed, and that the surface 
 must consequently be formed into 
 curves of the nature of linteariae, 
 which are supposed to be the re- 
 sults of a uniform tension of a 
 surface resisting the pressure of a 
 fluid, either uniform or varying 
 according to a given law. 
 
 Cohesion, the attraction which takes 
 place between the particles of bo- 
 dies, denoting that force by which 
 the particles firmly cohere. 
 
 Cohesion and resistance of fluids, as 
 examined by the force of torsion. 
 Pressure does not augment the 
 friction ; on the contrary, the re- 
 sistance is greater when the im- 
 mersion is only partial. Greasing 
 wood does not lessen the friction : 
 the friction of oil is 17 times as 
 great as that of water. A part of 
 the friction is proportional to the 
 velocity : the constant part is al- 
 most insensible. Thus a circle -195 
 metre in diameter, turning in water 
 with a velocity equal to '14m. in 1", 
 meets a resistance equivalent to 
 a weight of 1 gramme acting on 
 a lever of '143 m. The portion 
 proportional to the velocity is e- 
 quivalent to '042 gr. for a surface 
 equal to twice such a circle moving 
 in its own direction with a velocity 
 of -01 m. 
 
 Cohesive strength of materials. The 
 
COI 
 
 COKE. 
 
 COK 
 
 force of cohesion may be defined 
 to be that force by which the fibre* 
 or particles of a body resist sepa- 
 ration, and is proportioned to the 
 number of fibres in the body, or in 
 the area of its section. 
 
 Coiling, a serpentine winding of ropes, 
 by which they occupy a small space, 
 and are not liable to be entangled in 
 working the sails of a ship., 
 
 Coin, or quoin, the angle of a building; 
 used also for the machicolation of 
 a wall. 
 
 Coke, charred pitcoal. The most va- 
 luable of the secondary products of 
 a gas establishment is coke. The 
 best kind is obtainedfrom coalwhen 
 carbonized in large masses, in ovens 
 constructed on purpose. In a gas 
 manufactory, the production of 
 coke being of minor importance to 
 the formation of good gas, it is ge- 
 nerally of an inferior quality to that 
 made in coke ovens, where it is the 
 primary, and indeed sole object for 
 which the coal is carbonized. But 
 gas-coke is excellent for many pur- 
 poses in the arts and manufactures, 
 producing as clear a fire as that of 
 the first quality, though it is neither 
 so lasting nor so free from slag : for 
 domestic use, however, it is unob- 
 jectionable, and may be burnt both 
 in the drawing-room and kitchen 
 with economy and comfort. 
 
 The distinguishing characters of 
 good coke are, first, a clean, granu- 
 lar fracture in any direction, with 
 a pearly lustre, inclining to that 
 exhibited by cast-iron. Secondly, 
 density, or close proximity of its 
 particles, which adhere together in 
 masses, and specific gravity of 1*10, 
 or rather higher. Thirdly, when 
 exposed to a white heat, it con- 
 sumes entirely away, without leav- 
 ing either slag or ashes. 
 
 It is invariably the case that the 
 quality of the coke is inversely as 
 that of the gas. The manufacturer 
 must not expect to produce both of 
 the best quality. The process by 
 which the best gas is made gene- 
 rally leaves the coke light, spongy, 
 
 114 
 
 and friable, although an increase of 
 quantity is gained ; for the simple 
 reason, that the degree of heat and 
 other circumstances required to 
 form perfect coke must be entirely 
 changed when gas of a high specific 
 gravity is to be obtained. Thus 
 large masses of coal exposed to a 
 red heat in close vessels are acted 
 upon by slow degrees, the external | 
 portions preventing heat from pene- 
 trating into the interior until most 
 of the bituminous portions are given 
 off in condensable vapour, or as 
 charcoal and free hydrogen ; the 
 after products being light carbu- 
 retted hydrogen, carbonic oxide, 
 and carbonic-acid gases. The re- 
 sidue is a carbon of a dense granular 
 composition. 
 
 Coke, as prepared for use in locomo- 
 tive and other steam-engines, may 
 be regarded as purified coal, or coal 
 from which the extraneous matters 
 not conducive to combustion have 
 been expelled by the application of 
 heat. It appears from experiments 
 that the heating power of every 
 description of fuel, whether coal, 
 coke, wood, lignite, turf, or peat, 
 is proportional to the quantity of 
 carbon it contains, and that from 
 83 to 86 per cent, of this element 
 enters into the composition of any 
 given weight of Newcastle, D urham , 
 or Lancashire coal, the other in- 
 gredients being hydrogen, azote, 
 oxygen, and ashes. The exact pro- 
 cess which takes place in the con- 
 version of coal into coke is not yet 
 thoroughly understood, although 
 the result can be readily estimated, 
 and is found to depend, to a con- 
 siderable extent, upon the manner 
 in which the process is performed. 
 Thus, by coking in close ovens, 
 Welsh coal loses about 30 per cent, 
 of its weight ; but if the coking 
 be effected in uncovered heaps of 
 coarse lumps, as it often is in the 
 Welsh coal and iron districts (where 
 abundance is allowed, as the excuse 
 for extravagance and waste), the 
 loss of weight is from 50 to 55 
 
COL 
 
 COLLAR. 
 
 COL 
 
 per cent. While the weight is thus 
 diminished by coking in close 
 ovens, the bulk is increased from 
 22 to 23 per cent. The rapid and 
 complete combustion of the carbon 
 which takes place in the burning 
 of coke has the effect of preventing, 
 to a considerable extent, the emis- 
 sion of that palpable smoke which 
 arises from the combustion of coal ; 
 and for this property coke was 
 resorted to for use in locomotive 
 engines, when the non-emission of 
 smoke was imposed as one of the 
 conditions upon which railway 
 companies were empowered by Act 
 of Parliament. The practical ad- 
 vantages since found to be derived 
 from the burning of coke instead 
 of coal are, its greater power in 
 evaporating water and producing 
 steam, and the less rapid destruc- 
 tion of the boiler which ensues 
 from its employment. 
 
 Colarin, the little frieze of the capital 
 of the Tuscan and Doric column, 
 placed between the astragal and 
 the annulets. 
 
 Cold chisel, a piece of steel flattened 
 and sharpened at one end, which 
 is properly tempered, so that it 
 may be used for cutting metal. 
 
 Cold-harbour, an inn ; a shelter from 
 the cold ; a protection on the way- 
 side for travellers benighted or 
 benumbed. 
 
 Cold short iron, iron in an impure 
 state. 
 
 Cold-water well and reservoir. To 
 effect the condensation of steam, 
 the water is very commonly raised, 
 by means of the cold-water pump, 
 from a reservoir or well. This ab- 
 sorbs from the engine some portion 
 of its power. Indeed, when the 
 wells are deep, the quantity of 
 power thus expended is so great, 
 that the condensing system can 
 no longer be judiciously applied. 
 This may be known by the follow- 
 ing investigation : 
 
 Rule. Multiply the weight of 
 water, in pounds, by the feet 
 through which it passes in a minute, 
 
 and divide the product by 33,000 ; 
 the quotient will exhibit, friction 
 excluded, the horses' power ex- 
 pended. 
 
 Example. To condense 103; 
 
 Weight of cold water 10 ft. 
 per gallon, at 62 of tem- 
 perature, 
 
 Engine, nominal power . . 4 horses. 
 
 Water, per horse power . . 4 gals. 
 
 Lift of do., or height 
 raised, 230 feet per minute. 
 
 Hence 
 
 4 x 40 x 230 
 33,000 
 
 power. 
 
 Cold-water pump, the pump for sup- 
 plying the water for condensation. 
 
 Collar, in ships, an eye in the end or 
 bight of a shroud or stay, to go 
 over the mast-head. 
 
 Collar, in turnery, a ring inserted in 
 the puppet for holding the end of 
 the mandril next the chuck, in 
 order to make the spindle run 
 freely and exactly. 
 
 Collar, a plate of metal screwed down 
 upon the stuffing-box of a steam- 
 engine, with a hole to allow the 
 piston-rod to pass through. 
 
 Collar of a shaft, the timber and 
 boarding used to secure the upper- 
 most part of a shaft in loose rub- 
 ble from falling in. 
 
 Collar-beam, a beam framed across 
 and between two principal rafters. 
 
 Collision, in mechanics. Whenever 
 two bodies act on each other so as 
 to change the direction of their 
 relative motions, by means of any 
 forces which preserve their activity 
 undiminished at equal distances on 
 every side, the relative velocities 
 with which the bodies approach to 
 or recede from each other will al- 
 ways be equal at equal distances. 
 
 Colliquation, smelting or dissolving 
 anything by heat. 
 
 Colluviarium, anciently a well or 
 opening formed at intervals in the 
 channel of an aqueduct for procu- 
 ring a free current of air along its 
 course, and to facilitate the ope- 
 ration of clearing away foul depo- 
 sits left by the waters. 
 
 115 
 
COL 
 
 COLOURS, SYMBOLIC. 
 
 COL 
 
 Cologne earth is a native pigment, 
 similar to the Vandyke brown iif 
 its uses and properties as a colour. 
 
 Colonnade, a range of columns, 
 whether attached or insulated, and 
 supporting an entablature. 
 
 Colosseum, a name given to the theatre 
 of Vespasian, either from its mag- 
 nitude or from its colossal statue 
 of Nero ; also the name of a fine 
 building in the Regent's Park. 
 
 Colossus, a statue of gigantic dimen- 
 sions, or very much beyond the 
 proportions of nature. 
 
 Colour. The term colour being used 
 synonymously for pigment is the 
 cause of much ambiguity, particu- 
 larly when speaking of colours as 
 sensible or in the abstract; it would 
 be well, therefore, if the term pig- 
 ment were alone used to denote 
 the material colours of the pallet. 
 
 Colouring, in painting, the art of dis- 
 posing the tints, so as to produce 
 either an imitation of the natural 
 colours of the objects represented, 
 or force and brightness of effect. 
 Although a subject inferior to many 
 others which the painter must 
 study, this is yet of sufficient im- 
 portance to employ a considerable 
 share of his attention ; and to 
 excel in it, he must be well ac- 
 quainted with that part of optics 
 which has the nature of light and 
 colours for its object. Light, how- 
 ever simple and uncompounded it 
 may appear, is nevertheless made 
 up, as it were, of several distinct 
 substances; and the number and 
 quantity of component parts have 
 been happily discovered by the 
 moderns. 
 
 Colours (symbolic), in antiquity, the 
 middle ages, and modern times. 
 The history of symbolic colours is 
 but little known. Colours had 
 the same signification amongst all 
 nations of the remotest antiquity : 
 this conformity indicates a com- 
 mon origin, which extends to the 
 earliest state' of humanity, and 
 develops its highest energies in the 
 religion of Persia : the dualism of 
 
 116 
 
 light and darkness presents, in 
 effect, the two types of colours 
 which become the symbols of two 
 principles, benevolence and male- 
 volence. The ancients admitted 
 but two primitive colours, white 
 and black, whence all others are 
 derived. 
 
 The language of colours, inti- 
 mately connected with religion, 
 passed into India, China, Egypt, 
 Greece, and Rome, and re-ap- 
 peared in the middle ages ; the 
 large windows of Gothic cathedrals 
 found their explanation in the 
 books of the Zends, the Vedas, 
 and the paintings of the Egyptian 
 temples. 
 
 Among the Egyptians, the pro- 
 phets did not allow metal-founders 
 or statuaries to represent the gods, 
 lest they should deviate from the 
 rules. 
 
 At Rome, the penalty of death 
 was incurred by selling or being 
 clothed in a purple stuff. At this 
 day, in China, any one who wears 
 or buys clothes with the prohibited 
 design of the dragon or phoenix, 
 is subjected to 300 stripes and 
 three years' banishment. 
 
 Symbolism explains this severity 
 of laws and customs : to each co- 
 lour, to each pattern, appertained 
 a religious or political idea: to 
 change or to alter it was a crime 
 of apostasy or of rebellion. 
 
 Archaeologists have remarked 
 that Indian and Egyptian paint- 
 ings, and those of Greek origin, 
 named Etruscan, are composed of 
 plain tints of a brilliant colour, 
 but without demi-tints ; the pat- 
 tern and the colour had a necessary 
 signification, it was essentially 
 restrictive : perspective, chiaro- 
 oscuro, and demi-tints, would have 
 led to confusion. 
 
 Christianity, in recalling these 
 forgotten significations, restores a 
 new energy to the language of 
 colours : the doctrine taught by 
 Christ was not therefore new, since 
 it borrowed the symbols of ancient 
 
COL 
 
 COLOURS, SYMBOLIC. 
 
 COL 
 
 religions. The Son of God, in lead- 
 ing back mankind to the truth, 
 came not to change, but to fulfil 
 the law; this law was the worship 
 of the true God. 
 
 The three languages of colours, 
 divine, consecrated, and profane, 
 classify, in Europe, the three estates 
 of society, the clergy, the nobles, 
 and the people. 
 
 The large glass windows of 
 Christian churches, like the paint- 
 ings of Egypt, have a double sig- 
 nification, the apparent and the 
 hidden ; the one is for the uniniti- 
 ated, and the other applies itself to 
 the mystic creeds. The theocratic 
 era lasts to the Renaissance; at this 
 epoch, symbolic expressions are ex- 
 tinct; the divine language of co- 
 lours is forgotten, painting be- 
 came an art, and was no longer a 
 science. 
 
 The aristocratic era commences ; 
 and symbolism, banished from the 
 church, takes refuge at the court: 
 disdained by painting, it is found 
 again in heraldry. Modern paint- 
 ing still preserves its symbolism in 
 church pictures : St. John wears a 
 green robe, Christ and the Virgin 
 are likewise draped in red and blue, 
 and God in white. 
 
 Natural philosophy recognizes 
 seven colours, which form the solar 
 ray, decomposed by the prism ; 
 namely, violet, indigo, blue, green, 
 yellow, orange, and red. Painting 
 admits but five primitives, the 
 first and last of which are rejected 
 by natural philosophy, white, 
 yellow, red, blue, and black. 
 From the combination of these five 
 colours every hue is produced. 
 
 According to symbolism, two 
 principles produce all colours, light 
 and darkness. 
 
 Light is represented by white, 
 and darkness by black ; but light 
 does not exist but by fire, the sym- 
 bol of which is red : setting out 
 from this basis, symbolism admits 
 two primitive colours, red and 
 white. Black was considered as 
 
 117 
 
 the negation of colours, and at- 
 tributed to the spirit of darkness ; 
 red is the symbol of divine love ; 
 white, the symbol of divine wis- 
 dom. From these two attributes of 
 God, love and wisdom, the creation 
 | of the universe emanates. 
 
 Secondary colours represent dif- 
 ferent combinations of the two 
 principles ; yellow emanates from 
 red and white ; it is the symbol of 
 revelation of the love and of the 
 wisdom of God. 
 
 Blue emanates likewise from red 
 and white ; it indicates divine wis- 
 dom manifested by life, by the 
 spirit or the breath of God (air, 
 azure) ; it is the symbol of the 
 spirit of truth. 
 
 Green is formed by the union of 
 yellow and blue ; it indicates the 
 manifestation of love and wisdom 
 in action ; it was the symbol of 
 charity, and of the regeneration of 
 the soul by works. 
 
 Gold and yellow were, in Chris- 
 tian symbolism, the emblems of 
 faith : St. Peter was represented 
 by the illuminators and minia- 
 turists of the middle ages with a 
 golden-yellow robe, and the rod or 
 the key in his hand. 
 
 Christianity restored truth to 
 mankind, and reinstated symbolic 
 language in its original purity. In 
 the Transfiguration, the counte- 
 nance of our Lord became resplen- 
 dent as the sun, and his vesture 
 shone like the light. Such, in their 
 highest energy, are the symbols of 
 divine love and wisdom. The angel 
 who rolled away the stone from 
 the sepulchre reproduced them in 
 an inferior order, his face shone 
 like lightning, and his robe was 
 white as snow. Finally, in the last 
 degree, appeared the just, in robes 
 washed white in the blood of the 
 Lamb. The artists of the middle 
 ages preserved their precious tra- 
 ditions, and gave to Jesus Christ, 
 after the resurrection, a white or 
 red costume. 
 Columbaria, the holes left in walls 
 
COL 
 
 COMBUSTION. 
 
 COM 
 
 for the insertion of pieces of tim- 
 ber; so called from resembling 
 tbe niches of a pigeon-house. The 
 niches of a mausoleum, made to 
 receive the cineral urns, were like- 
 wise termed columbaria. The co- 
 lumbarium was a place of sepul- 
 ture used for the ashes of the 
 Romans, after the custom of burn- 
 ing the dead had been introduced 
 among them. 
 
 Columen, the term applied to the 
 upright timbers of a roof, corre- 
 sponding to the modern kingposts. 
 
 Column, in architecture, a member 
 of a cylindrical form, placed up- 
 right for support of buildings, 
 principally wrought in stone, and 
 made decorative in conformity to 
 the order and style of architectural 
 composition. It consists of a base, 
 a shaft or body, and a capital, and 
 differs from the pilaster, which is 
 square on the plan. 
 
 Columns, in architecture, ac- 
 cording to Vitruvius, were of the 
 three orders. The proportions of 
 Corinthian columns are in every 
 respect, excepting their capitals, 
 similar to those of Ionic ; although 
 their form is more graceful and 
 proportionably more delicate, by 
 reason of the greater height of the 
 capitals; for Ionic capitals are a 
 third part only of the lower dia- 
 meter of the columns, whereas 
 the Corinthian capital is equal 
 in height to an entire diameter. 
 The peculiar character of the ca- 
 pitals, which admits of their being 
 higher than those of Ionic co- 
 lumns by two-thirds of a diameter, 
 gives beauty to them, bypermitting 
 an increase of the height without 
 violating the laws of symmetry. 
 
 Combustion, the operation of fire 
 upon an inflammable substance, 
 by which it smokes, flames, and is 
 reduced to ashes. 
 
 Few or no chemical combinations 
 can take place without a disturb- 
 ance in the equilibrium of caloric 
 in the substances to be so com- 
 bined ; and when caloric is thereby 
 
 118 
 
 evolved in sufficient extent and 
 rapidity, and when one or all the 
 bodies engaged may be freely com- 
 bustible, ignition takes place. 
 When this is unintentional, or is 
 the result of ignorance or care- 
 lessness, it is convenient to call it 
 spontaneous combustion. Thus we 
 frequently hear of hayricks, etc., 
 on fire ; occasionally of carts 
 loaded with quicklimebeing burned 
 by the rain falling upon the lime. 
 There are also somewhat apocry- 
 phal accounts of coal in coal-yards 
 being destroyed in like manner. 
 But the most important instance 
 of this class, as far as regards the 
 preservation of Government esta- 
 blishments, is the combustion that 
 infallibly and rapidly ensues when 
 greasy hemp, flax, or cotton, is 
 allowed to remain loosely heaped 
 together, in any quantity, in a 
 confined unventilated space. Full 
 proof of this has been made by 
 experiment in the dockyards ; and 
 there is much reason to attribute 
 many fires in former days to care- 
 lessness in the rope-walks and 
 hemp-stores ; in consequence of 
 which, rigorous orders have been 
 of late years issued as to the im- 
 mediate disposal of loose oakum 
 and hemp sweepings all more or 
 less greased or oiled. The very 
 oil-rags used by engravers iu clean- 
 ing plates, when heaped together 
 to any amount, will be consumed 
 in a few hours. 
 
 The combination in question 
 seems to be between the oil and 
 the oxygen of the atmosphere. 
 Oil has always an affinity for 
 oxygen ; though, when the bulk of 
 the former is considerable in pro- 
 portion to the surface, the action 
 is but feeble, and the results not 
 ordinarily appreciable : but in the 
 case of admixture of such fibrous 
 vegetable bodies as hemp, flax, or 
 cotton with oily matters, where 
 the ratio of surface to solidity is 
 great, and when the conditions for 
 accumulating heat are favourable, 
 
COM 
 
 COMPARTMENT. 
 
 COM 
 
 this accumulation soon produces 
 ignition amongst such inflammable 
 bodies as those just enumerated. 
 
 Come. ' Come home ;' said of an an- 
 chor when it is broken from the 
 ground, and drags. To ' come up ' 
 a rope or tackle, is to slack it off. 
 
 Commandry, a religious house be- 
 longing to a body of knights of 
 the order of St. Bernard and St. 
 Anthony. 
 
 Commissure, the joins between two 
 stones, in masonry. 
 
 Common pitch, an old term still ap- 
 plied by country workmen to a 
 roof in which the length of the 
 rafters is about three-fourths of 
 the entire span. 
 
 Common sewer of Rome : it was near 
 the Senatorian bridge, and was 16 
 feet in diameter. 
 
 Communication valves, the valves in 
 a steam-pipe which connects two 
 boilers to an engine, for cutting off 
 the communication between either* 
 boiler and the engine. 
 
 Communion table, a piece of church 
 furniture usually placed near the 
 wall of the east end of the chan- 
 cel, and enclosed by rails, within 
 which the clergyman stands to 
 administer the Sacrament. 
 
 Companion, a wooden covering over 
 the staircase to a ship's cabin. 
 
 Compartition, the division or distri- 
 bution of the ground-plan of an 
 edifice into its various apartments. 
 
 Compartment of the streets within 
 a city. According to Palladio, re- 
 gard must be always had to the 
 temperature of the air, and also to 
 the region of heaven, or the cli- 
 mate under which the place is 
 situated ; because where the air is 
 cold or temperate, there the streets 
 ought to be made large and noble, 
 since thereby the city will become 
 more wholesome, convenient, and 
 beautiful : it being certain that 
 the less piercing, and the freer the 
 air is, the less will it offend the 
 head ; and therefore the more a 
 town is situated in a cold place, or 
 in a piercing air, and the houses are 
 
 119 
 
 high, the longer ought the streets 
 to be made, that they may be vi- 
 sited by the sun in every part. 
 
 Compartment, a division or separate 
 part of a general design. 
 
 Compass (Harris's magneto-electric). 
 The inventor's object, in the appli- 
 cation of his discovery of the stea- 
 dying action of the copper ring, 
 " is the combination of great sensi- 
 tiveness with stability and simpli- 
 city of construction ; so that while 
 the needle is free to obey the mag- 
 netic force of the earth in the most 
 perfect way, it yet remains tran- 
 quil amidst the disturbing motions 
 to which a ship is exposed ; and 
 this stability is obtained without 
 the aid of friction or other me- 
 chanical impediment, which often 
 produce an apparent steadiness or 
 rather sluggishness of the com- 
 pass (arising from indifference to 
 motion), at the expense of ac- 
 curacy. 
 
 " When the horizontal position 
 of the card is disturbed by any 
 alteration of dip incidental to a 
 change of latitude, it is to be cor- 
 rected by moving the silver sliders 
 on the needle. 
 
 " Should the compass be out of 
 use, care must be taken to let the 
 needle hang freely in the meridian ; 
 and if put into a store-room, or 
 otherwise set by, the card and 
 needle should be removed alto- 
 gether, and placed with the needle 
 downward in the shallow box pro- 
 vided for it, the north point being 
 on that part of the keeper marked 
 with a cross, thus x . A good 
 compass is liable to deterioration 
 and damage when stowed away 
 without regard to its magnetic 
 properties, and without due care 
 being taken to preserve the agate 
 and the point of suspension in a 
 perfect state." 
 
 Compasses, an instrument with two 
 long legs, working on a centre pin 
 at one extremity ; used for draw- 
 ing circles, measuring distances, 
 setting out work, etc. 
 
COM 
 
 COMPOSITION. 
 
 COM 
 
 Compass-headed, in ancient architec- 
 ture, circular. 
 
 Compass-plane, in joinery, a tool si- 
 milar to the sraoothing-plane in 
 size and shape, but the sole is 
 convex, and the convexity is in 
 the direction of the length of the 
 plane. The use of the compass- 
 plane is to form a concave cylin- 
 drical surface, when the wood to 
 be wrought upon is bent with the 
 fibres in the direction of the curve, 
 which is in a plane surface perpen- 
 dicular to the axis of the cylinder : 
 consequently, compass-planes must 
 be of various sizes, in order to 
 accommodate different diameters. 
 
 Compass-roof, a roof in which the 
 braces of the timbers are inclined 
 so as to form a sort of arch. 
 
 Compass-saw, in joinery, a tool for 
 cutting the surfaces of wood into 
 curved surfaces : for this purpose it 
 is narrow, without a back, thicker 
 on the cutting edge, as the teeth 
 have no set : the plate is about 
 an inch broad, next to the handle, 
 and diminishes to about one quar- 
 ter of an inch at the other extre- 
 mity ; there are about five teeth in 
 the inch: the handle is single. 
 
 Compass-window, a bay window, or 
 oriel. 
 
 Complement (the) of an arch or angle 
 is what it wants of 90 degrees : thus 
 the complement of 50 is 40, and 
 the complement of 40 is 50. 
 
 Compluvium (Latin), the interval be- 
 tween the roofs of porticoes which 
 surround the cavsedium. The rain 
 was admitted through this opening 
 and fell upon the area below, 
 which was termed by some authors 
 the impluvium. 
 
 Composite Order: by some considered 
 not a distinct order, but a variety 
 of the Corinthian. For its height 
 and proportion, see Architecture, 
 Orders. 
 
 Care must be taken in Compo- 
 site as well as in Corinthian capi- 
 tals, that the feet of the lower 
 leaves do not project beyond the 
 upper part of the column, as at 
 
 120 
 
 St. Carlo, in the Corso at Rome, 
 and at the Banqueting-house in 
 London ; for nothing can be uglier. 
 Neither are these leaves, as they 
 mount, to bend forwards, as in 
 many of the antiques, and in some 
 modern buildings, because they 
 then hide a considerable part of 
 the upper row of leaves, and give 
 a stunted disagreeable form to the 
 whole capital. The different divi- 
 sions of the acanthus-leaf, and 
 bunches of olive or parsley which 
 compose the total of each leaf, 
 must be firmly marked, and massed 
 in a very distinct manner : the 
 stems that spring from between 
 the upper leaves are to be kept 
 low upon the vase of the capital, 
 while rising between the leaves, 
 then spring gradually forwards, to 
 form the different volutes ; and 
 the ornaments, which sometimes 
 are used to adorn the sides of the 
 , angular volutes, are never to pro- 
 ject beyond the fillets between 
 which they are confined. 
 
 Composition of motion, in mechanics, 
 an assemblage of several directions 
 of motion resulting from several 
 powers acting in different though 
 not in opposite directions. 
 
 Composition, in painting, is a tasteful 
 and proper distribution of the ob- 
 jects of a picture, in grouping, in 
 the attitudes, in the draperies and 
 the management of the back- 
 ground. In architecture, the seve- 
 ral parts which constitute a temple 
 ought to be subject to the laws of 
 symmetry, the principles of which 
 should be familiar to all who pro- 
 fess the science of architecture. 
 Symmetry results from proportion, 
 which, in the Greek language, is 
 termed analogy. Proportion is the 
 commensuration of the various 
 constituent parts with the whole ; 
 in the existence of which, sym- 
 metry is found to consist ; for no 
 building can possess the attributes 
 of composition in which symmetry 
 and proportion are disregarded, 
 nor unless there exists that perfect 
 
COM 
 
 CONCRETE. 
 
 CON 
 
 conformation of parts which may 
 be observed in a well-formed hu- 
 man being. 
 
 Compound arch, according to Profes- 
 sor Willis, an arch which has the 
 archivolt moulded or formed into a 
 series of square recesses and angles, 
 on the principle that " it may be 
 resolved into a number of concen- 
 tric archways successively placed 
 within and behind each other." 
 
 Compound pier, a term applied to a 
 clustered column. 
 
 Compression, the result of pressing 
 or squeezing matter so as to set its 
 parts nearer to each other, and to 
 make it occupy less space. 
 
 Computation, the method of esti- 
 mating time, weights, measures, 
 etc. 
 
 Concamerate, to arch over. 
 
 Concameratio, arched work. 
 
 Concave, a term denoting the curvi- 
 linear vacuity of hollow bodies. 
 
 Concentric, having a common centre ; 
 as concentric circles, ellipses, etc. 
 
 Concha, according to Dr. Whewell, a 
 term for the concave ribless sur- 
 face of a vault. 
 
 Conclave, a private or secret council ; 
 an inner room for meeting pri- 
 vately. 
 
 Concluding line, a small line leading 
 through the centre of the steps of 
 a rope or Jacob's ladder. 
 
 Concrete, a composition of lime, 
 sand, pebbles, or other materials, 
 now commonly used for the foun- 
 dations of buildings. The general 
 employment of the mixtuie of 
 lime and gravel, commonly known 
 by the name of concrete, in all 
 foundations where, from the nature 
 of the soil, precautions against 
 partial settlements appear neces- 
 sary, and the great probability of 
 an extension of its use in situa- 
 tions where the materials of which 
 it is composed are easily and 
 cheaply procured, must of course 
 render it a subject of great inte- 
 rest to the engineer. Much va- 
 luable information on this subject 
 will be found in a prize essay by 
 
 121 
 
 Mr. G. Godwin, published in the 
 ' Transactions of the Institute of 
 British Architects.' In this essay, 
 many instances are brought for- 
 ward of the employment by the 
 ancients of a mixture analogous 
 to concrete, both for foundations 
 and for walls. Several cases are 
 also mentioned in which, of late 
 years, it has been used advanta- 
 geously for foundations, by some 
 of the most distinguished architects 
 and civil engineers. In these lat- 
 ter instances, the proportion of the 
 ingredients varies from one of lime 
 and two of gravel, to one of lime 
 and twelve of gravel, the lime 
 being in most cases Dorking lime, 
 and the gravel, Thames ballast. 
 The proportion, however, most 
 commonly used now, in and about 
 London, is one of lime to seven of 
 ballast; though, from experiments 
 made at the building of the West- 
 minster New Bridewell, it would 
 appear that one of lime to eight of 
 ballast made the most perfect con- 
 cretion. 
 
 Concrete, compounded solely of 
 lime and screened stones, will 
 never assume a consistence at all 
 equal to that of which sand forms 
 a part. The north wing of Buck- 
 ingham Palace affords an instance 
 of this : it was first erected on a 
 mass of concrete composed of lime 
 and stones, and when subsequent 
 alterations made it necessary to 
 take down the building and remove 
 the foundation, this was found not 
 to have concreted into a mass. 
 
 Mr. Godwin states, as the result 
 of several experiments, that two 
 parts of stones and one of sand, 
 with sufficient lime (dependent on 
 the quality of the material) to 
 make good mortar with the latter, 
 formed the best concrete. As the 
 quality of the concrete depends, 
 therefore, on the goodness of the 
 mortar composed of the lime and 
 sand, and as this must vary with 
 the quality of the lime, no fixed 
 proportions can of course be laid 
 
CON 
 
 CONCRETE. 
 
 CON 
 
 down which will suit every case. 
 The proportions must be deter-" 
 mined by experiment ; but in no 
 case should the quantity of sand 
 be less than double that of the 
 lime. 
 
 The best mode of compounding 
 the concrete is to thoroughly mix 
 the lime, previously ground, with 
 the ballast in a dry state ; sufficient 
 water being then thrown over it to 
 effect a perfect mixture, it should 
 be turned over at least twice with 
 shovels, and then wheeled away 
 instantly for use. In some cases, 
 where a great quantity of concrete 
 has to be used, it has been found 
 advisable to employ a pug-mill to 
 mix the ingredients : in every case 
 it should be used hot. 
 
 With regard to the quantity of 
 water that should be employed in 
 forming concrete, there is some 
 difference of opinion ; but as it is 
 usually desirable that the mass 
 should set as rapidly as possible, it 
 is not advisable to use more water 
 than is necessary to bring about a 
 perfect mixture of the ingredients. 
 A great change of bulk takes place 
 in the ingredients of concrete when 
 mixed together : a cubic yard of 
 ballast, with the due proportion of 
 lime and water, will not make a 
 cubic yard of concrete. Mr. God- 
 win, from several experiments made 
 with Thames ballast, concludes that 
 the diminution is about one-fifth. 
 To form a cubic yard, therefore, of 
 concrete, the proportion of lime 
 being ^th of the quantity of ballast, 
 it requires about 30 cubic feet of 
 ballast, and 3| cubic feet of ground 
 lime, with sufficient water to effect 
 the admixture. 
 
 An expansion takes place in the 
 concrete during the slaking of the 
 lime, of which an important use 
 has been made in the underpinning 
 of walls : the amount of this ex- 
 pansion has been found to be about 
 fths of an inch to every foot in 
 height; and the size thus gained, 
 the concrete never loses. 
 
 122 
 
 The examples from which the 
 above rules are deduced are princi- 
 pally of buildings erected in or 
 about London ; the lime used is 
 chiefly from Dorking, and the bal- 
 last from the Thames. It is very 
 desirable that a more extended 
 collection of facts should be made, 
 that the proportions of the mate- 
 rials, when other limes and gravels 
 are used, should be stated, in order 
 that some certain rules may be laid 
 down by which the employment of 
 concrete may be regulated under 
 the various circumstances which 
 continually present themselves in 
 practice. 
 
 The Dorking and Hailing limes 
 are slightly hydraulic. Will com- 
 mon limes, such as chalk, and 
 common stone-lirne, answer for 
 forming foundations of concrete, 
 where the soil, although damp, is 
 not exposed to running water ? Is 
 it possible, even with hydraulic 
 lime, to form a mass of concrete in 
 running water ? If common lime 
 will not answer, may it not be 
 made efficient by a slight mixture 
 of cement ? These, and questions 
 similar to these, are of great in- 
 terest; and facts which elucidate 
 them will be valuable contributions 
 to the stock of knowledge on this 
 subject. 
 
 It is a question for consideration, 
 whether a great variety of sizes in 
 the materials used would not form 
 the most solid as well as the hardest 
 wall. The walls of the fortress of 
 Ciudad Rodrigo, in Spain, are of 
 concrete. The marks of the boards 
 which retained the semi-fluid mat- 
 ter in their construction are every- 
 where perfectly visible ; and besides 
 sand and gravel, there are every- 
 where large quantities of round 
 boulder-stones in the walls, from 
 4 to 6 inches in diameter, procured 
 from the ground around the city, 
 which is everywhere covered with 
 them. 
 
 Condensation, the conversion of va- 
 pour into water by cold. 
 
CON 
 
 CONDUCTION, ELECTRICAL. 
 
 CON 
 
 Condenser, in steam-engines, the ves- 
 sel connected with the exhaust-port 
 of the cylinder of a low-pressure 
 engine, and also with the air-pump, 
 by a passage at the bottom fitted 
 by the foot-valve of the pump : it 
 receives the steam from the cylin- 
 der, and condenses it by a jet of 
 cold water, thus forming a vacuum 
 for the return stroke : the water, 
 air, etc., are then drawn off by the 
 air-pump, and discharged into the 
 hot well. 
 
 Conditorium, a secret place ; a sepul- 
 chre ; a vault. 
 
 Conduction, electrical, a series of 
 phenomena in electricity, giving 
 origin to a classification of sub- 
 stances as conductors of electricity. 
 The substances which properly 
 come under this conducting or non- 
 electric class are principally as fol- 
 lows : 
 
 LIST OF ELECTRICAL CONDUCTORS. 
 
 Every metallic substance known. 
 
 Well-burned charcoal. 
 
 Plumbago. 
 
 Concentrated and diluted acids, 
 
 and saline fluids. 
 
 Water, and moist vegetable matter. 
 Living animal matter. 
 Flame smoke steam. 
 
 The distinctive difference in the 
 conducting and non - conducting 
 property of bodies may be readily 
 illustrated in the following way : 
 Excite a glass tube and wire, and 
 bring the ball of the wire into 
 contact with any of the electrics, 
 as a rod of glass, a stick of sealing- 
 wax, or brimstone rendered per- 
 fectly dry : the attractive power of 
 the ball and wire, together with 
 the tube, will not be in any sensi- 
 ble degree impaired. Let the elec- 
 trified ball now touch the walls of 
 the room or other conducting sub- 
 stance communicating with the 
 ground ; the attractive power will 
 instantly vanish. 
 
 It is evident from these facts 
 that all electric substances are non- 
 conductors or insulators, as they 
 are appropriately termed ; whilst, 
 
 on the other hand, non-electric 
 substances are transmitters or con- 
 ductors of electrical action. When, 
 therefore, any conducting sub- 
 stance is placed on an electrical 
 support, such as a rod of glass or 
 shell-lac, it is considered to be 
 insulated, and is termed an insu- 
 lated conductor; when electrified 
 by contact with any excited or 
 other electrified body, it is said 
 to be charged. The electrical 
 charge thus communicated to an 
 insulated conductor appears to be 
 collected about its surface, and to 
 be rather dependent on that than 
 on the solid content. Thus, if two 
 metallic spheres or cylinders, the 
 one solid, the other hollow and 
 extremely light, be suspended by 
 silk lines, or placed on dry insu- 
 lating supports, and be charged by 
 contacts with an excited tube, the 
 attractive energy of each upon any 
 light substance presented to it will 
 be found quite alike in each. In 
 this experiment the insulators must 
 be very dry and perfect. 
 
 The best insulating substances 
 are of the vitreous and resinous 
 class, such as shell-lac, brimstone, 
 dry glass rods, vitrified and crys- 
 talline bodies : to these may be 
 added silk. 
 
 The best conducting substances 
 are principally metallic bodies, sa- 
 line fluids, and common charcoal. 
 
 It should, however, be here un- 
 derstood, that modern researches, 
 especially those of Faraday, lead us 
 to conclude that there are really 
 no substances which perfectly con- 
 duct or perfectly obstruct electrical 
 action. The insulating and con- 
 ducting power is, in fact, a differ- 
 ence of degree only : still, the ex- 
 treme differences are so great, that 
 if classed in relation to such dif- 
 ferences, those at the extremes of 
 the series admit of being considered 
 the one as insulators, the other as 
 conductors ; whilst the interme- 
 diate terms are made up of sub- 
 stances which may be considered 
 
 r, 9 
 
CON 
 
 CONICAL POINTS. 
 
 CON 
 
 as imperfect, taken as either. Con- 
 versely, every substance is capable 
 of excitation by friction ; yet the 
 differences in this respect are so 
 great as to admit of some bodies 
 being called electrics and others 
 non-electrics, with an intermediate 
 class between these extremes, 
 which may be termed imperfect 
 electrics. 
 
 Series of conductors and insu- 
 lators. Metals and concentrated 
 acids are found at the conducting 
 extremity of such a series, shell- 
 lac, brimstone, all vitreous and 
 resinous bodies, at the other or 
 electric extremity ; whilst the im- 
 perfect or intermediate substances 
 comprise such matter as common 
 earth and stones, dry chalk, mar- 
 ble, porcelain, paper, and alkaline 
 matter. 
 
 The attractive power evinced by 
 any electrical body in a state of 
 excitation, although the first and 
 usually the most evident electrical 
 effect, is yet not the only force 
 which seems to result from this 
 curious condition of common mat- 
 ter. On a closer examination of 
 the phenomena, a new class of 
 facts present themselves, of re- 
 markable interest. If the excita- 
 tion be considerable, and the at- 
 tracted body insulated, it will, after 
 being drawn into contact with the 
 electrified substance, rebound from 
 it with great violence, as if repelled 
 by some new power, and will not 
 be again attracted until it has had 
 conducting communication with 
 the earth, or some other mass of 
 matter capable of reducing it to its 
 original condition before the con- 
 tact. 
 
 Conduit, a structure forming a reser- 
 voir for water, and from which it 
 is drawn for use. 
 
 Cone, a solid body having a circular 
 base, and its other extremity ter- 
 minating in a single point or vertex. 
 Cones are either right or oblique. 
 
 Cone-plate, a strong plate of cast iron 
 fixed vertically to the bed of a lathe, 
 
 124 
 
 with a conical hole in it, to form a 
 support for the end of a shaft 
 which it is required to bore. 
 
 Confessional, a recess or seat in which 
 the priest sits to hear the confes- 
 sions of penitents. 
 
 Conge, another name for the echinus 
 or quarter-round, as also for the 
 cavetto : the former is called the 
 swelling conge, the latter the hol- 
 low conge. 
 
 Conic sections, the curves formed by 
 the intersection of a circular cone 
 and a plane ; the former being 
 either oblique or right. 
 
 Conical points, in turnery, the cones 
 fixed in the pillars for supporting 
 the body to be turned : that on the 
 right hand is called the fore centre, 
 and that on the left hand, the back 
 centre. 
 
 Conissinet, the stone which crowns a 
 pier, or that lies immediately over 
 the capital of the impost, and 
 under the sweep. The bed of it is 
 level below, and curved above, 
 receiving the first rise or spring of 
 the arch or vault. 
 
 Conisterium, an apartment in the pa- 
 laestra, in which sand was kept for 
 sprinkling the athletae, after they 
 had been anointed. 
 
 Connecting-rods, in locomotive en- 
 gines, the strong iron rods which 
 connect the piston to the driving- 
 wheel axle, and thus give motion 
 to all the machinery. 
 
 Connecting-rods, in locomotive en- 
 gines, outside or side rods, those 
 which connect together the wheels 
 of good engines. They are seen 
 outside the wheels, making an ir- 
 regular forward motion, like water- 
 men rowing a boat. By connect- 
 ing the wheels together, one pair 
 cannot slip without the others, 
 and the greatest practicable adhe- 
 sion is thus obtained. 
 
 Connecting-rod straps, in locomotive 
 engines, strong pieces of iron bent 
 like the letter c, which fit the 
 ends of the connecting-rod; and 
 into which the axle-bearing is fitted 
 in two parts. They are attached 
 
CON 
 
 CONSERVATORY. 
 
 CON 
 
 to their respective ends of the rod 
 by keys and cotters, which are 
 taken out, and the half of the 
 bearing also, when a connecting- 
 rod has to be put on. The strap 
 and half-bearing are then brought 
 over the axle or cross-head, the 
 other half-bearing put into the 
 strap, the end of the rod brought 
 up against the bearing, and se- 
 cured by the keys and cotters. 
 Taking off a rod is of course the 
 reverse of putting one on. 
 
 Connecting-rod bearings, in locomo- 
 tive engines, the gun-metal or 
 composition metal bearings fitted 
 into the straps, to suit the parti- 
 cular part they are to work on. 
 
 Conning, directing the helmsman in 
 steering a vessel. 
 
 Conservation, the ceremony of sanc- 
 tifying or making holy. 
 
 Conservatory, a superior kind of 
 greenhouse, for preserving curious 
 and rare exotic plants. It is made 
 with beds of the finest composts, 
 into which the trees and plants are 
 removed for culture and preser- 
 vation. Its construction is more 
 capacious than the ordinary green- 
 house, and it is furnished in a 
 superior style, provided with a 
 free admission of light, and, in 
 addition, with flues or boiling- 
 water pipes to raise the tempera- 
 ture when necessary, and also 
 contrivances for the introduction 
 of fresh air. 
 
 Consideration (the), which one onght 
 to have before he begins to build. 
 Palladio says, " The first thing that 
 requires our consideration, when 
 we are about to build, is the plan, 
 and the upright of the edifice we 
 propose to erect." Three things, 
 according to Vitruvius, are chiefly 
 to be considered, without which a 
 building cannot be of any value. 
 These are, conveniency, solidity, 
 and beauty : for no edifice can be 
 allowed to be perfect, if it be com- 
 modious and not durable; or, if 
 being durable, it be subject to 
 many inconveniences ; or if having 
 
 both solidity and conveniency, it 
 has no beauty or uniformity. 
 
 Consistory court, a spiritual court, ! 
 formerly held in the nave of the 
 cathedral church. 
 
 ''Console, a bracket or truss, mostly 
 with scrolls or volutes at the two 
 ends, of unequal size and con- i 
 trasted, but connected by a flowing 
 line from the back of the upper I 
 one to the inner convolving face of \ 
 the lower. 
 
 Constant white, permanent white, or j 
 barytic white, is a sulphate of ha- i 
 rytes, and, when well prepared and ; 
 free from acid, is one of the best ! 
 whites for water-painting, being of 
 superior body in water, but desti- 
 tute of this quality in oil. 
 
 Construction, in architecture : for this 
 the chief requisites are, magnitude 
 and strength, and the art of distri- 
 buting the different forces and 
 strains of the parts and materials 
 of a building in so scientific a 
 manner as to avoid failure and to 
 insure durability. 
 
 Continuous imposts, according to Pro- 
 fessor Willis, are the mouldings of 
 an arch which are continued with- 
 out interruption down the uprights 
 to the ground or base, the impost 
 point having no mark or distinc- 
 tion of any kind. 
 
 Contouring (surveying altitudes and 
 levels). This term is applied to 
 the outline of any figure, and con- 
 sequently to that of any section of 
 a solid body ; but when used pro- 
 fessionally, in connection with the 
 forms of ground, or of works of 
 defence, the outline of a horizontal 
 section of the ground, or works, is 
 alone to be understood by it. 
 
 When the forms of ground, or 
 works, are described by contours, 
 or horizontal sections, these sec- 
 tions are taken at some fixed ver- 
 tical interval from each other, 
 suited to the scale of the drawing, 
 or to the subject in hand; and the 
 distance of each, above or below 
 some assumed plane of compari- 
 son, is given in figures at the most 
 
 125 
 
CON 
 
 COPPER. 
 
 COR 
 
 convenient places on the plan. 
 When the scale of the drawing r3 
 about 100 feet to an inch, 2 or 3 
 feet will be found a convenient 
 vertical interval between the con- 
 tours ; and however large the scale 
 of the plan, it will scarcely be 
 found necessary to obtain contours 
 with a less vertical interval than 2 
 feet. If the scale of the plan be 
 about 250 feet to an inch, or the 
 ordinary special survey scale of 4 
 chains to an inch, 5 feet will prove 
 a convenient vertical interval : and 
 with a horizontal scale of from 500 
 to 800 feet per inch, 10 feet may 
 be taken as the vertical interval. 
 
 In tracing and surveying the 
 contours of ground, the following 
 process may be adopted : com- 
 plete the survey of the occupation 
 of the ground, the streams, etc., 
 and determine carefully the alti- 
 tudes of the trigonometrical points 
 employed above the intended place 
 of comparison ; take an accurate 
 trace from the plot of one of the 
 triangles, which, if the distances 
 between the trigonometrical points 
 are properly proportioned to the 
 scale of the plan, will generally be 
 a convenient piece in point of size 
 to contour ; take this trace to the 
 ground, and find upon the ground, 
 and mark upon the trace the points 
 where each of the intended con- 
 tours will cut the boundary lines of 
 the triangle. 
 
 Contraction, the effect of cold upon 
 a warm body, causing a diminution 
 in its size by the particles ap- 
 proaching each other. 
 
 Contramure, an out-wall built about 
 the wall of a city or fortification. 
 
 Convent, a building appropriated to 
 religious persons ; a nunnery. 
 
 Convocation and Convocators, or par- 
 liament of tinners. All Stannary 
 laws are enacted by the several 
 convocations, and carry with them 
 all the force and law of acts of 
 parliament. 
 
 Coopertorium, the roof of a building. 
 
 Co-ordinates, in the theorv of curves, 
 
 any absciss and its corresponding 
 ordinate. 
 
 Cope (to), to jut out as a wall. 
 
 Cope (to), to cover over an arch. 
 
 Coping, the reversing course of a 
 wall, either flat or sloping on the 
 upper surface, to throw off water. 
 
 Coppe-house, anciently a tool-house. 
 
 Copper, one of the six primitive 
 metals, and the most ductile and 
 malleable after gold and silver. Of 
 this metal and lapis calaminaris is 
 made brass, which is comparatively 
 a modern invention. 
 
 Copper green (colour); the appellation 
 of a class rather than of an indi- 
 vidual pigment, under which are 
 comprehended verdigris, verditer, 
 malachite, mineral green, green 
 bice, Scheele's green, Schweinfurt 
 or Vienna green, Hungary green, 
 emerald green, true Brunswick 
 green, lake green, mountain green, 
 African green, French green, Saxon 
 green, Persian green, patent green, 
 marine green, Olympian green, etc. 
 The general characteristic of these 
 greens is brightness of colour, well 
 suited to the purposes of house- 
 painting, but not adapted to the 
 modesty of nature in fine art. 
 
 Coral wood is of a fine red colour, 
 hard, and polishable. 
 
 Corbel, or Corbeille, a short piece of 
 timber or stone let into a wall half 
 its length or more, as the burthen 
 superimposed may require, to carry 
 a weight above it, and projecting 
 from the general face of the work: 
 it is carved in various fanciful ways ; 
 the commonest form is, however, 
 that of an ogee. 
 
 ^Corbel, in Gothic architecture, a pro- 
 jecting stone or piece of timber 
 which supports a superincumbent 
 weight. 
 
 Corbel-table, a cornice supported by 
 corbels. 
 
 Corbie steps, steps up the sides of a 
 gable, found in old houses in Flan- 
 ders, Holland, etc. 
 
 Corbona, in mining, a dropper from a 
 
 lode in irregular masses. 
 -Corbs, ornaments in architecture. 
 
 126 
 
COR 
 
 CORONA. 
 
 COR 
 
 Cordon, the edge of stone on the out- 
 side of a building. 
 Core, with the Cornish tinmen, is a 
 
 division of time and lahour. 
 Corinthian Order. The three columns 
 in the Campo Vaccino, supposed 
 remains of the temple of Jupiter 
 Stator, are generally allowed to be 
 the most perfect models of the 
 Corinthian order amongst the an- 
 tiques at Rome. Palladio, in his 
 fourth book, where he gives the 
 whole profile at large, acknow- 
 ledges that he never had seen any 
 work better executed, or more deli- 
 cately finished ; that its parts are 
 beautifully formed, well-propor- 
 tioned, and skilfully combined ; all 
 which last qualities are certainly 
 signified by his benissimo intesi. 
 
 With these favourable senti- 
 ments, it is extraordinary that, in 
 his design of the Corinthian order, 
 he should have so very considerably 
 deviated from this excellent origi- 
 nal as scarcely to leave the smallest 
 shadow of resemblance. 
 
 Vignola, in his Corinthian pro- 
 file, has chiefly imitated the above- 
 mentioned fragment, and the inte- 
 rior order of the Pantheon, another 
 very perfect model. His compo- 
 sition is uncommonly beautiful, 
 and, without dispute, superior to 
 that of any other master: he art- 
 fully collected all the perfections 
 of his originals, and formed a whole 
 far preferable to either of them. 
 
 Corinthian Brass. Gold, silver, and 
 copper, casually mixed together at 
 the burning of the city of Corinth, 
 there being a great many statues 
 and vessels melted down and so 
 embodied. 
 
 Corner-stones, in architecture, the two 
 stones which stand one in each joint 
 of the chimney. 
 
 Corneus, a kind of tin ore, found in 
 black columns, with irregular sides, 
 
 / and terminating in prisms. 
 
 Cornice, the projection, consisting of 
 several members, which crowns or 
 finishes an entablature, or the body 
 or part to which it is annexed. The 
 
 127 
 
 cornice used on a pedestal is called 
 the cap of the pedestal. 
 
 Cornish engine, a single-acting beam 
 engine, used for raising water ; the 
 steam is worked very expansively, 
 and used for the down-stroke only, 
 to raise an immense weight, fas- 
 tened to the pump-rod, at the end 
 of the beam : the steam having 
 acted for the down-stroke, and the 
 entrance-valve being closed, a com- 
 munication is formed between the 
 top and bottom of the cylinder, by 
 lifting a valve in the steam passage, 
 called an equilibrium valve ; the 
 pressures on the piston are thus 
 equalized, and the weight acts to 
 force the water up, and raise the 
 piston. 
 
 ^Cornucopia, or horn of plenty; among 
 architects, painters, etc., it is repre- 
 sented under the figure of a large 
 horn, out of which issue fruit, 
 flowers, etc. 
 
 Corollary, an inference or deduction. 
 
 Coromandel wood, the produce of 
 Ceylon and the coast of India, is 
 shipped in logs and planks from 
 Bombay and Madras ; it is of a red 
 hazel-brown colour, handsome for 
 furniture wood, and turns well. 
 
 Corona, the members constituting the 
 uppermost of the three divisions of 
 the entablature of a portico, or any 
 other building in which columns 
 are introduced ; this division is 
 termed cornice. 
 
 Corona, that flat, square, and massy 
 member of a cornice, more usually 
 called the drip or larmier, whose 
 situation is between the cymatium 
 above and the bed-moulding below; 
 its use is to carry the water drop 
 by drop from the building. 
 
 Corporate cloth, a linen cloth or nap- 
 kin spread upon the altar, on which 
 the host and chalice are placed at 
 the mass in the Catholic service. 
 
 Corpse-gate, a covered place at the 
 entrance to a churchyard, intended 
 to shelter the corpse and mourners 
 from rain. 
 
 Correggio (Antonio Allegri); of the 
 Lombard school he acquired the art 
 
COR 
 
 COTTON. 
 
 COU 
 
 of modelling. His early style was 
 acquired probably from Andrejf 
 Mantegna. 
 
 ^Corridor, a gallery or open communi- 
 cation to the different apartments 
 of a house. 
 
 Corrugated Iron, a design for the 
 strength of iron beams or girders, 
 in the employment of corrugated 
 sheet iron. This was the subject 
 of a patent, granted in 1848 to 
 Mr. J. H. Porter, " for an improved 
 mode of applying corrugated iron 
 in the formation of fire-proof floors, 
 roofs, and other structures." 
 
 Coma, the name given by Vitruvius to 
 a platband or square fascia whose 
 height is more than its projecture. 
 
 Cortile, a small court enclosed by the 
 divisions or appurtenances of a 
 building. 
 
 Cords, in the middle ages, a court 
 surrounded by edifices. 
 
 Coryceum, a room similar to a tennis- 
 court. 
 
 Cosecant of an arch, the complement 
 of another to 90 degrees. 
 
 Costean pits, in Cornish mining, are 
 shallow pits sunk to trace or find tin. 
 
 Costeaning, in mining, the discover- 
 ing of lodes by sinking pits in their 
 vicinity, and drawing transversely 
 to their supposed direction. 
 
 Cot, in nautical phraseology, a bed- 
 frame suspended from the beams 
 of the ship, or otherwise. 
 
 Cotangent, is the tangent of any com- 
 plemental arch, or what the arch 
 wants of a quadrant or 90 degrees. 
 
 Cotton, a white woolly or downy 
 substance, found in a brown bud, 
 produced by a shrub, the leaves of 
 which resemble those of the syca- 
 more-tree. The bud, which grows 
 as large as a pigeon's egg, turns 
 black when ripe, and divides at 
 top into three parts ; the cotton is 
 as white as snow, and with the 
 heat of the sun swells to the size 
 of a pullet's egg. Scripture speaks 
 of cotton. 
 
 Cotton manufactures and trade. Cot- 
 ton was woven by the Hindoos and 
 Chinese many centuries before the 
 
 128 
 
 Christian era. The Egyptians are 
 supposed to have imported woven 
 cotton before the plant had begun 
 to be cultivated in their country, 
 and the Romans received woven 
 cotton from India long before the 
 cotton-plant was known in Europe. 
 The extension of the manufacture 
 of it has now become enormous. 
 The export of cotton goods from 
 England, in 1846, was 25,600,693 
 in value. 
 
 The distinctive names by which 
 cotton is known in commerce are 
 mostly derived from the countries 
 which produce it ; the exceptions 
 are, sea-island cotton, and upland 
 cotton. The former of these was 
 first cultivated in the low sandy 
 islands near the coastof Charleston, 
 in America, while the latter is 
 grown in the inner or upland 
 country. The sea-island cotton is 
 the finest of the several varieties. 
 The upland is often called Bowed 
 Cotton. 
 
 The spinning of cotton into the 
 form of yarn or thread requires 
 many preparatory processes ; but 
 the inventions and improvements 
 in machinery that have been ef- 
 fected in recent years have rendered 
 the process simple and of great 
 national value. 
 
 Cotton and Calico printing, the art 
 of staining woven fabrics of cotton 
 with various figures and colours. 
 
 Cotton, ffun, is prepared with cotton 
 wool, and explodes at 400 Fahr. 
 Gunpowder explodes at 600. 
 
 Couched, laid close, as in a stratum. 
 
 Couissinet. (See Conissinet.} 
 
 Coulisse, any piece of timber which 
 has grooves in it ; also pieces of 
 wood which hold the floodgates in 
 a sluice. 
 
 Counter, that part of a vessel between 
 the bottom of the stern and the 
 wing transom and buttock. 
 
 Counterfort, a pier, buttress, or ob- 
 lique wall, built up against a wall 
 to strengthen and support it. 
 
 Counter-gauge, in carpentry, a method 
 of measuring joints by transferring 
 
cou 
 
 COUNTRY RESIDENCES. 
 
 COU 
 
 the breadth of a mortise to the 
 place on another timber where the 
 tenon is to be made. 
 
 Counter-lath, in tiling, a lath placed 
 by the eye. 
 
 Counterpoise, any weight which, 
 placed in opposition to another 
 weight, produces an equilibrium ; 
 but it is more commonly used to 
 denote the weight used in the Ro- 
 man balance, or steelyard. 
 
 Countersinks, in joinery, are bits for j 
 widening the upper part of a hole j 
 in wood or iron, for the head of a i 
 screw or pin, and have a conical j 
 head. Those for wood have one 
 cutter in the conic surface, and 
 have the cutting edge more remote 
 from the axis of the cone than any 
 other part of the surface. Coun- 
 tersinks for brass have eleven or 
 twelve cutters round the conic sur- 
 face, so that the horizontal section 
 represents a circular saw. These 
 are called rose-countersinks. The 
 conic angle at the vertex is about 
 90 degrees. Countersinks for iron 
 have two cutting edges, forming an 
 obtuse angle. 
 
 I Counterview, in painting, a contrast 
 or situation in which two things 
 illustrate or set off each other. 
 
 Counters, in ships, two parts of a ship 
 called the upper and lower counter. 
 
 Count-house, a reckoning-house, in 
 Derbyshire ; a house or room on 
 the mine used for keeping accounts 
 of the products, etc. 
 
 Country residences. There are im- 
 portant advantages which deserve 
 to be brought into notice, whether 
 for comfort and convenience, for 
 gratifying taste or fashion. Addi- 
 tional rooms appropriated for new 
 purposes are often requisite. For- 
 merly a gallery, although there were 
 no works of art to fill it, was a ne- 
 cessary part of a mansion ; of late 
 years, the billiard-room and the 
 conservatory enter into the arrange- 
 ments of an architect ; and a suit 
 of well-planned nursery-rooms have 
 been made a necessary part of the 
 plan of a country mansion. The 
 
 129 < 
 
 gallery is again about to resume its 
 importance, and perhaps we may 
 hereafter imitate the Romans in 
 having covered walks contiguous 
 to the house, in order to enjoy 
 fresh air in the many rainy and 
 snowy days at a country residence 
 in an English winter. The irregu- 
 lar style admits of such additions, 
 arid loses nothing of the picturesque 
 effect. The exterior decorations of 
 terraces, parterres, stairs of com- 
 munication, and different gardens 
 filled with groups of the many 
 flowering shrubs and plants, are ad- 
 mirably in harmony with this style 
 of architecture. While we thus 
 decorate closely around the house, 
 it becomes less necessary to sacri- 
 fice so much to the park. The 
 masonry of such irregular archi- 
 tecture requires not the expen- 
 sive labour bestowed on a Grecian 
 or Roman mansion. The whole 
 should be in rough rubble-work, 
 excepting the parapets, the corners, 
 the windows, and doors. Many 
 very good designs of castellated 
 dwellings have been, in the execu- 
 tion, deprived of their effect, by 
 being built of smooth, hewn free- 
 stone. If circular or square towers 
 are introduced in a composition of 
 the irregular style, they should, in 
 every case, be of great dimensions, 
 as much for their being applied to 
 useful rooms, as to produce that 
 grandeur of appearance which bulk 
 in towers always gives. 
 
 The Country-seats of the Ita- 
 lians have been copied by most civi- 
 lized nations of Europe ; celebrated 
 by poets, visited and admired by 
 travellers : they have not, however, 
 been described or represented as 
 they deserve. They are so ar- 
 ranged as to produce the best 
 effect, and advantage of the nature 
 of the site has been taken with 
 admirable skill. The regularities 
 of the gardens accompany the de- 
 coration, and support the architec- 
 ture. (See Parker's 'Villa Rus- 
 tica,' recently published.) 
 
cou 
 
 COUPLINGS. 
 
 COW 
 
 Couple-close, a pair of spars of a roof; 
 also used by heralds as a diminu-* 
 tive of the chevron. 
 
 Coupled columns. When, from the 
 extent between columns sometimes 
 necessary for the introduction of 
 doors, windows, niches, or other 
 decorations, neither the eustylos 
 nor the diastylos intercolumniation 
 can be used, coupled columns are 
 frequently introduced. In this case 
 two sistylos intercolumniations are 
 used ; the column which would 
 otherwise occupy the middle of the 
 space being brought to the distance 
 of only half a diameter (or suffi- 
 cient room for the projection of 
 the capitals) from the extreme 
 column. The middle space will 
 then be three diameters and a half. 
 This species has been called araeo- 
 sistylos. When buildings are small, 
 the intercolumniations will not re- 
 quire such particular attention to 
 the foregoing rules, for columns 
 should never be placed nearer to 
 each other than three feet, which 
 will allow for the easy passage of 
 a bulky person. 
 
 Coupling, in machinery, is the name 
 given to various arrangements by 
 which the parts of a machine may 
 be connected or disconnected at 
 pleasure, or by which a machine 
 may be disengaged from, or re- 
 engaged with, a revolving wheel or 
 shaft, through which it receives 
 motion from a steam-engine, water- 
 wheel, or other prime mover. 
 Couplings, in mill-work : it is fre- 
 quently necessary to convey motion 
 much farther than would be prac- 
 ticable by any one shaft, and there- 
 fore often requisite to connect two 
 or more shafts together. These 
 connections are denominated cou- 
 plings, and may be divided into two 
 classes: 1st, Those having two 
 bearings ; 2ndly, Those having one 
 bearing. Couplings having two 
 bearings have been long in use, 
 and before those having one bear- 
 ing, and are generally more simple 
 in their construction. 
 
 130 
 
 Coupling-box, a metal box for joining 
 the ends of two shafts, so that they 
 may revolve together. 
 Course, a continuous range of stones 
 or bricks, of uniform height, in the 
 wall of a building. 
 
 Course, in Cornish mining, is a tin 
 or copper course; a phrase for 
 working of the lode. 
 Courses, sails that hang from a ship's 
 lower yards : the fore-sail is called 
 the fore-course, and the main-sail 
 the main-course. 
 
 Courts of Justice: there were in 
 Rome twelve halls or courts of 
 justice, where causes were heard 
 and tried : they were adorned with 
 statues, fine columns, and porticoes 
 with double rows of columns. 
 /Cove, a cave, a recess ; any kind of 
 concave moulding; the concavity 
 of an arch or of a ceiling. 
 Coved ceiling, the upper surface of an 
 apartment formed in an arched or 
 coved shape at its junction with 
 the side walls. 
 
 Covenants of the Old and New Testa- 
 ment (The Two), in the Table of 
 Symbols of the early ages, are re- 
 presented by the wheel in the 
 middle of a wheel. Ezek. i. 1 6. 
 Cover, in slating, the part of the slate 
 that is hidden; the exposed part 
 being called the margin. 
 Cover-way, in roofing, the recess or 
 internal angle left to receive the 
 covering. 
 
 Cover, a turret or cupola on the rooi 
 of a hall or kitchen, pierced at the 
 sides to let out smoke or steam. 
 Covie or Covey, a pantry. 
 Coving, the exterior projection of the 
 upper parts of a building beyond 
 the limits of the ground-plan. 
 Coving, a term applied to houses, etc., 
 that project over the ground-plot. 
 Coving of a fireplace, the vertical 
 sides, inclining backwards and in- 
 wards, for the purpose of reflecting 
 the heat. 
 
 Cowl, a cover for the top of a chim- 
 ney, made to turn round by the 
 wind, and used to facilitate the 
 escape of smoke. 
 
cox 
 
 CRANK. 
 
 CRE 
 
 ] Cowner, an arch part of a ship's stern. 
 j Coxswain, the person who steers a 
 
 hoat, and has charge of her. 
 ! Crab, a wooden apparatus, something 
 like a capstan, hut not furnished 
 with a drum-head ; it is used for 
 similar purposes, with holes made 
 to insert the bars. 
 
 Crab, a machine with three claws, 
 used to launch ships, to heave 
 them into the dock, or off the quay. 
 
 Cradle, a frame placed under the bot- 
 tom of a ship, in order to conduct 
 her steadily into the water when 
 she is to be launched, at which 
 time it supports her weight while 
 she slides down the descent or 
 sloping passage, called the Ways, 
 which are for this purpose daubed 
 with soap or tallow. 
 
 Craft, a general name for all sorts of 
 vessels employed to load or dis- 
 charge merchant ships, or to carry 
 alongside or return the guns, stores, 
 or provisions of a man-of-war : such 
 are lighters, hoys, barges, etc. 
 
 Cramp, a short bar of iron, with its 
 ends bent so as to form three sides 
 of a parallelogram : at one end a 
 set-screw is inserted, so that two 
 pieces of metal, being placed be- 
 tween, can be held firmly together 
 by the screw. 
 
 Crane, a machine used for hoisting and 
 lifting stones, ponderous weights, 
 and heavy goods, principally at 
 wharfs and warehouses, now much 
 employed for hoisting heavy build- 
 ing materials ; also as travelling 
 cranes on framed scaffolding, for 
 the assistance of masons, brick- 
 layers, anji other artisans in build- 
 ing, saving the time and labour 
 formerly so much prolonged in the 
 execution of the work to be done. 
 
 Cranes, pieces of iron or timber at a 
 vessel's sides, used to stow boats 
 or spars upon. 
 
 Crank, the condition of a vessel when 
 she is inclined to lean over a good 
 deal, arid cannot bear much sail : 
 this may be owing to her construc- 
 tion, or to her stowage. 
 
 Crank, the arms projecting from the 
 
 131 
 
 main shaft of an engine, joined to- 
 gether at the outer ends. 
 
 Crank, in mechanics, a square piece 
 projecting from a spindle, serving 
 by its rotation to raise and fall the 
 pistons of engines : it also denotes 
 the iron support for a lantern, and 
 the iron made fast to the stock of 
 a bell. 
 
 Crank, in machinery, is a bend in an 
 axle, by which a reciprocating mo- 
 tion in a rod is made to produce a 
 revolving motion of an axle and of 
 a wheel which may be connected 
 with it. 
 
 Crank, in turning that part of the 
 axle of the fly which is bent into 
 three knees, or right angles, and 
 three projecting parts : one of the 
 parts is parallel to the axis, and 
 has the upper part of the crank- 
 hook collared round it. 
 
 Crank-axle, the driving axle con- 
 nected to the piston-rods of a loco- 
 motive engine. 
 
 Crank-hook, in turning, sometimes 
 also called the connecting-rod, as it 
 connects the treadle and the fly. 
 
 Crank-pin, the cylindrical piece join- 
 ing the ends of the crank arms, 
 and attached to the connecting- 
 rod, or, in vibrating engines, to 
 the piston-rod : if the crank has 
 only one arm, the pin projects 
 from the end of it. 
 
 Crayon, a chalk ; a species of mate- 
 rial for drawing. Black chalk, 
 found in Italy, white chalk, found 
 in France, and red chalk, form 
 three of the best varieties of cra- 
 yons : each has its own peculiar 
 value as a drawing material. 
 
 Creates, in mining, the work or tin 
 in the middle part of the huddle 
 or dressing. 
 
 Credence, the small table at the side 
 of the altar, or communion table, 
 on which the bread and wine were 
 formerly placed before they were 
 consecrated. 
 
 Creeper, an iron instrument like a 
 grapnel, with four claws, used for 
 dragging the bottom of a harbour 
 or river, to find anything lost. 
 
CRE 
 
 CROSS. 
 
 CRO 
 
 Cremona school of painting, Boc- v 
 caccio Boccaccino bears the same* 
 character among the Cremonese, 
 as Ghirlandajo, Mantegna, Vanucci, 
 etc., in their respective schools. 
 Caraillo Boccaccino was the chief 
 master of this school, grounded in 
 the ancient maxims of his father. 
 
 Crenelle, the embrasure of a battle- 
 ment, or loopholes. 
 
 Crepido, according to Pliny, any 
 raised basement upon which other 
 things are built or supported, as of 
 a temple, altar, obelisk, etc. 
 
 Crescent, or half-moon. 
 
 Cresset, a candlestick or lamp to 
 contain a light. 
 
 Crest, a term in heraldry ; the orna- 
 ment of the helmet. 
 
 Creste, the ornamented finishing sur- 
 rounding a screen or canopy of a 
 building. 
 
 Crest-tiles, those used to cover the j 
 ridge of a roof, upon which they 
 fit on the principle of a saddle. 
 
 Creux, a kind of sculpture, when the 
 lines and figures are cut and formed 
 within the face of the plate. 
 
 Cringle, a short piece of rope with 
 each end spliced into the bolt-rope 
 of a sail, confining an iron ring or 
 thimble. 
 
 Criplings, short spars at the sides of 
 houses. 
 
 Crista, a crest ; the apex or highest 
 
 part of a shrine. 
 
 Brockets, ornaments of foliage or 
 animals running up the back of a 
 pediment, arch-pinnacle, or spire, 
 from the corbels below to the 
 finial above, in which latter the 
 crockets on both sides appear to 
 merge. Projecting leaves, flowers, 
 or bunches of foliage, used in 
 Gothic architecture to decorate the 
 angles of spires, canopies, pinna- 
 cles, etc. 
 
 Cromlech, in British antiquity, high, 
 broad, and flat stones, raised upon 
 other stones set on end, apparently 
 for the purpose of an altar. 
 Crop, ore or tin of the first quality, 
 after it is dressed or cleaned for 
 smelting. 
 
 132 
 
 Crosette, a truss, or console, in the 
 flank or return of an architrave of 
 a door, window, or other aperture 
 in a wall. 
 
 Crosettes, in decoration, the trusses 
 or consoles on the flanks of the 
 architrave, under the cornice. 
 
 Cross-beam, a beam laid across an- 
 other. In a ship, a great piece of 
 timber so called, crossing two 
 others, called bites, and to which 
 the cable is fastened, when a ship 
 rides at anchor. 
 
 Cross-jack, in a ship, is a small yard 
 flung at the upper end of the 
 mizen-mast under the top. 
 
 Cross, a gibbet constructed of two 
 pieces of wood placed transversely, 
 whether they cross each other at 
 right angles at the top, like a T, 
 or in the middle of their length, 
 like an X. 
 
 Cross, the symbol of the Christian 
 religion. 
 
 Cross, cross crusse, cross-bar, cross 
 yoffan, cross lode, either a vein of 
 a metallic nature, or a soft earth, 
 clay, or flookan, like a vein, which 
 unheads and intersects the true 
 lode. 
 
 Cross-bars, round bars of iron bent 
 at each end, used as levers to turn 
 the shank of an anchor. 
 
 Cross-chocks, pieces of timber fayed 
 across the deadwood amidships, to 
 make good the deficiency of the 
 heels of the lower futtocks. 
 
 Cross (church), or a Greek cross, that 
 in which the length of the trans- 
 verse part is equal to that of the 
 nave ; so called because most of 
 the Greek churches were built in 
 that form. 
 
 Cross (church), or a Latin cross, that 
 whose nave is longer than the cross 
 part, as in most Gothic churches. 
 
 Cross-grained stuff, in joinery, wood 
 having its fibres running in con- 
 trary positions to the surfaces, and 
 which consequently cannot be made 
 perfectly smooth when planed in 
 one direction, without turning it 
 or turning the plane. 
 
 Cross-heads, in locomotive engines, 
 
CRO 
 
 CRYPT. 
 
 CRY 
 
 the part of the motion into which 
 the piston-rod is fitted on the cy- 
 linder side and the connecting-rod 
 attached on the driving wheel axle 
 side. 
 
 Cross-head guides, in locomotive en- 
 gines, the parallel bars between 
 which the cross-head moves in a 
 right line with the cylinder and 
 driving wheel axle : they are also 
 called motion bars. 
 
 Cross-head blocks, in locomotive en- 
 gines, the parts which slide between 
 the parallel guides. The ends of 
 the cross-head are fitted into these 
 blocks. The cross-head, cross- 
 head guides, and block, constitute 
 what is called ' the motion of the 
 engine.' 
 
 Cross-head, in the steam-engine, a 
 cross-bar fixed centrally on the top 
 of a piston-rod, and connected to 
 the beam: its motion is confined 
 to a direct line by guides at each 
 end ; or, in the side-lever and beam 
 engines, by an apparatus called a 
 ' parallel motion.' 
 
 Cross-jack : the cross-jack yard is the 
 lower yard on the mizen-mast. 
 
 Cross-spales, pieces of timber placed 
 across a vessel, and nailed to the 
 frames, to keep the sides together 
 until the knees are bolted. 
 
 Cross-somer, a beam of timber. 
 
 Cross-springer, in groined vaulting, 
 the rib which extends diagonally 
 from one pier to another. 
 
 Cross-trees, pieces of oak supported 
 by the cheeks and trestle-trees at 
 the mast-heads, to sustain the tops 
 on the lower mast, and to spread 
 the top-gallant rigging at the top- 
 mast head. 
 
 Cross vaulting is formed by the inter- 
 section of two or more simple 
 vaults of arch-work. 
 
 Crotchet, a support, or piece of wood 
 fitted into another to sustain it. 
 Also crooked pieces of iron, used 
 on board sloops and long-boats. 
 
 Croud, or Crowde, a crypt, or under- 
 croft of a church. 
 
 Crow, in mechanics, an iron lever, 
 made with a sharp point at one 
 
 133 
 
 end, and two claws at the other ; 
 used in heaving and purchasing 
 great weights. 
 
 Crow-foot, a number of small lines 
 rove through to suspend an awning. 
 
 Crown, in geometry, a plane ring in- 
 cluded between two concentric 
 perimeters, generated by the mo- 
 tion of part of a right line round 
 the centre, to which the moving 
 part is not contiguous. 
 
 Crown of an anchor, the place where 
 
 the arms are joined to the shank. 
 ''Crown of an arch, that line or point 
 upon its surface which is the 
 highest or most elevated from its 
 springing. 
 
 Crown-post, the middle post of a 
 trussed roof. 
 
 Crown-wheels. Circular motion is 
 communicated at right angles by 
 means of teeth or cogs situated 
 parallel to the axis of the wheel. 
 Wheels thus formed are denomi- 
 nated ' crown' or ' contrate wheels : ' 
 they act either upon a common 
 pinion or upon a lantern. 
 
 Crozier, the pastoral staff of a bishop 
 or mitred abbot, having the head 
 curled round somewhat in the 
 manner of a shepherd's crook. 
 
 Crucifix, a representation of our 
 blessed Saviour on the cross. 
 
 Crustce, figures or images in low 
 relief, embossed upon plate. 
 
 Crustarius, an artist; an engraver 
 for inlaid work, etc. 
 
 Crutch, a knee or piece of knee 
 timber, placed inside a vessel to 
 secure the heels of the cant-tim- 
 bers abaft. 
 
 Cryophorus, an instrument by which 
 the freezing qualities of the atmo- 
 sphere may be ascertained. 
 
 Crypt, a vault beneath a building, 
 either entirely or partly under- 
 ground, frequently under churches 
 and cathedrals. 
 
 Crypta, or Crypt, among the Romans, 
 any long narrow vault, whether 
 wholly or partially below the level 
 of the earth. 
 
 Crypto Portico, an enclosed gallery 
 or portico having a wall with 
 
CTE 
 
 CUPBOARDS. 
 
 CUP 
 
 openings or windows in it, instead 
 of columns at the side. 
 
 Ctesibica machina, a double-actioned 
 forcing-pump invented byCtesibius 
 of Alexandria. 
 
 Cuare (Cornish), a quarry of stones. 
 
 Cubature, the cubing of a solid, or 
 measuring of the space compre- 
 hended in a solid, as in a cone, 
 pyramid, cylinder, etc. 
 
 Cube, in geometry, a regular or solid 
 body consisting of six square and 
 six equal faces and sides, and its 
 angles all right and therefore 
 equal. 
 
 Cube, or Hexahedron, a solid regular 
 body, consisting of six equal square 
 sides. 
 
 Cubes, or Cube numbers in arithmetic, 
 and the theory of numbers, are 
 those whose cube-root is a com- 
 plete integer ; or they are numbers 
 produced by multiplying a given 
 number twice into itself, or by the 
 multiplication of three equal fac- 
 tors. 
 
 Cube-root, of a number, say 8, the 
 number which multiplied into itself 
 twice will produce 8, namely, 2 ; 
 or it is that number by which, if 
 you divide a number twice, the 
 quotient will be equal to itself. 
 
 Cubic foot of water, what a vessel 
 one foot square and one foot deep 
 will hold. 
 
 Cubicule, among the Romans, a bed- 
 chamber, tent, or balcony. 
 
 Cubiculum, according to Pliny, a 
 room furnished with a sofa or bed. 
 
 Cubile, the ground-work or lowest 
 course of stones in a building. 
 
 Cubit, a measure used among the 
 ancients, and which the Hebrews 
 call ' amma,' the mother of other 
 measures. A cubit was originally 
 the distance from the elbow to the 
 extremity of the middle finger ; 
 which is the fourth part of a well- 
 proportioned man's stature. 
 
 Cubital, a bolster or cushion for the 
 elbow to rest upon, for invalids. 
 
 Cuboch, a name for the unit or in- 
 teger of a power, being the effect 
 produced by one cubic foot of 
 
 134 
 
 water in one foot perpendicular 
 descent. 
 
 Cuckold's -neck, a knot by which a 
 rope is secured to a spar, the two 
 parts of the rope crossing each 
 other and seized together. 
 
 Cuddy, a cabin in the fore part of a 
 boat. 
 
 Culage, the laying up a ship in the 
 dock, to be repaired. 
 
 Cul-de-four of a niche, arched roof of 
 a niche, on a circular plan, a sphe- 
 rical vault. 
 
 Cul-de-lampe, for several decorations 
 
 both of masonry and ironery. 
 1 Cullis, a gutter in a roof; any groove 
 or channel. 
 
 Culm, stone coal, resembling the Kil- 
 kenny coal of Ireland. 
 
 Culmen, the roof of a house or 
 church. 
 
 Culverhouse, a dove-cot or pigeon- 
 house. 
 
 Culvert, an arched drain for the pas- 
 sage of water. 
 
 Culvert, an arched passage or bridge 
 beneath a road, canal, or railway. 
 
 Culver-tail, to dove-tail. 
 
 Cuneus, the wedge. 
 
 Cuneus, the division of the audience 
 part of a theatre comprehended 
 between two adjoining scalaria or 
 staircases which lead from one 
 pra3cinctio to another: so called 
 from its form, which resembles a 
 wedge. The foremost cunei were 
 termed ' cavea prima ;' the middle, 
 'cavea media;' and the uppermost, 
 ' cavea summa.' The whole of the 
 audience part, exclusive of the or- 
 chestra, was likewise called ' cavea.' 
 
 Cupboards answered in some respects 
 to the sideboards of the present 
 day. They were sometimes mere 
 planched tops, resting on trestles, 
 or fixed with legs against the 
 wall ; at others, framed on stages, 
 rising one above another, and 
 moveable : these were called 
 ' joined cupboards,' occasionally 
 carved, and, like tables, covered 
 with carpets. At the marriage of 
 Prince Arthur, son of Henry VII., 
 in the hall was a triangular cup- 
 
CUP 
 
 CYCLOIDAL CURVES. 
 
 CYC 
 
 board, five stages high, set with' 
 plate, valued at 1200, entirely 
 ornamental ; and in the " utter 
 chamber," where the princess 
 dined, was another cupboard, " set 
 with gold plate, garnished with 
 stone and pearl," and valued at 
 20,000. 
 
 'Cupola, a small room, either circular 
 or polygonal, standing on the top 
 of a dome : by some it is called 
 a lantern. 
 
 Cupola, a spherical or spheroidal 
 covering to a building, or any part 
 of it. 
 
 Cup-valve, for a steam-engine : it re- 
 sembles a conical valve, made to 
 fit a cover in the form of a vase or 
 of the portion of a sphere. 
 
 Curia, in architecture; the building 
 in which the highest council of the 
 Roman state assembled, described 
 by Vitruvius as being adjacent to 
 the agora or forum. 
 
 Cur ling -stuff, in joinery, that which 
 is produced by the winding or 
 coiling of the fibres round the 
 boughs of a tree, when they begin 
 to shoot out of the trunk. 
 
 Current '; a stream or flux of water in 
 any direction. The setting of the 
 current is that point of the com- 
 pass towards which the waters 
 run ; and the drift of a current is 
 the rate it runs per hour. 
 
 Curtilage, a term formerly applied to 
 the division or boundary of mano- 
 rial lands. 
 
 Curve, in geometry, a line wherein 
 the several points of which it con- 
 sists tend several ways, or are po- 
 sited towards different quarters. 
 
 Curvilinear, consisting of curved 
 lines. 
 
 Cushion- capital, the capital of a co- 
 lumn so sculptured as to resemble 
 a cushion pressed down by the 
 weight of its entablature. 
 
 Cushions and window -pillows were, in 
 Tudor times, stuffed not unlike 
 the woolsack of the Lord Chancel- 
 lor in round, square, and oblong 
 shapes, covered with carpet-work, 
 velvet, or embroidery ; the family 
 
 135 
 
 arms frequently supplying the de- 
 vice. 
 
 , an ornament generally in Gothic 
 windows or doors ; it is to be found 
 in the concave bends of stone-work. 
 
 'Cusps, projecting points forming the 
 featherings or foliation in Gothic 
 tracery, archery, panels, etc. 
 
 Cut, in mining, to intersect a vein, 
 branch, or lode, by driving hori- 
 zontally or sinking perpendicularly 
 at right angles. 
 
 Cutter, a small boat ; also a kind of 
 sloop. 
 
 Cutting. Cutting instruments act in 
 dividing bodies upon the same 
 principle as the wedge. The blade 
 of the instrument is in general a 
 thin wedge, but the edge itself is 
 usually much more obtuse. 
 
 Cutwater, in a ship, is the sharp part 
 of the head under the beak or 
 figure. 
 
 Cycle, a round of time ; a space in 
 which the same revolution begins 
 again ; a periodical space of time. 
 A lunar cycle is a period of nine- 
 teen years. A solar cycle is a 
 period of twenty-eight years, after 
 which the days of the month re- 
 turn to the same days of the week. 
 
 Cyclograph, or Arcograph, an instru- 
 ment for drawing arcs of circles 
 without centres, used in architec- 
 tural aitd engineering drawings 
 when the centres are too distant 
 to be conveniently accessible. 
 
 Cycloidal curves are defined as fol- 
 lows : 1. When a circle is made to 
 rotate on a rectilinear basis, the 
 figure described on the plane of 
 the basis by any point in the plane 
 of the circle is called a trochoid : 
 a circle concentric with the gene- 
 rating circle, and passing through 
 the describing circle. 2. If the 
 describing point is in the circum- 
 ference of the rotating circle, the 
 two circles coincide, and the curve 
 is called a cycloid. 3. If a circular 
 basis be substituted for a rectilinear 
 one, the trochoid will become an 
 epitrochoid, and the cycloid an 
 epicycloid. 
 
CYC 
 
 CYPRESS-TREE. 
 
 CYZ 
 
 Cyclopean Architecture, a class of 
 building supposed to have preceded 
 the invention of the classic orders 
 in Greece, and attributed to the 
 Cyclopes. 
 
 Cyclopean wall, the oldest example of 
 mason-work in Italy: in town-walls 
 only has this style of building been 
 used. The history of its origin is 
 obscure. A large irregular mass 
 of stone, having three, four, five, 
 or more sides, hewn only on the 
 irregular sides to be built upon, 
 begins a wall : to this mass others 
 are added, the sides of which are 
 made to fit the irregular sides of 
 the first block ; and on these again 
 others of similar forms are built in 
 the same manner. 
 
 Cyclostylar, relating to a structure 
 composed of a circular range of 
 columns without a core; with a 
 core, the range would be a peri- 
 style. 
 
 Cylinder, a body having two flat sur- 
 faces and one circular : for in- 
 stance, a roller is a cylinder. 
 
 Cylinder, a roller used for levelling 
 and condensating the ground in 
 agricultural and other operations. 
 
 Cylinders, in steam-engines, hollow 
 cylindrical vessels : within the cy- 
 linder the steam exerts its power 
 upon the piston, which, by means 
 of its rod, transmits it to the other 
 parts of the engine. In locomotive 
 engines, hollow vessels, usually 
 made of cast-iron, and bored out 
 accurately, into which pistons are 
 fitted steam-tight, yet easily mov- 
 able by the pressure of the steam. 
 
 Cylinder cocks, in steam-engines, 
 cocks placed in convenient parts 
 of the cylinder for admitting oil to 
 lubricate the piston, or by which 
 to blow out the condensed steam, 
 or any deposit in the cylinders. 
 
 Cylinder cover, in steam-engines, the 
 lid bolted to a flanch round the top 
 of a cylinder, so as to be perfectly 
 
 136 
 
 steam-tight : it has a stuffing-box 
 cast in the centre, through which 
 the piston-rod alternates. 
 
 Cylindrical vault, a vault without 
 groins, resting upon two parallel 
 walls. 
 
 Cylindrical walling is that erected 
 upon a circular plan, forming a 
 cylinder, or a part less than a cy- 
 linder, according as the plan is an 
 entire circumference or a less por- 
 tion. 
 
 Cyling, anciently ceiling, 
 
 Cyma, called also cymatium, its name 
 arising from its resemblance to a 
 wave ; a moulding which is hollow 
 in its upper part, and swelling be- 
 low. There are two sorts, the 
 Cyma recta, just described, and 
 the Cyma reversa, whose upper- 
 part swells, whilst the lower part 
 is hollow. 
 
 Cymatium, a moulding whose section 
 or profile is convex below and con- 
 cave above, somewhat resembling 
 the letter S. 
 
 Cymatium, in sculpture, carved work, 
 resembling rolling waves. 
 
 Cymophane, a mineral of a green 
 colour, resembling the chrysoberyl. 
 
 Cypress-tree, one of the evergreens ; 
 very proper to mix with pines and 
 firs in forming clumps. The wood 
 of the cypress is very valuable, 
 when grown to a size fit for planks, 
 which dimension it attains in as 
 short a time as oak. It was much 
 used by the ancients, and was em- 
 ployed in the original doors of St. 
 Peter's at Rome, which, on being 
 replaced, after six hundred years, 
 by gates of brass, were found to be 
 perfectly free from decay, and with- 
 in to have retained part of the ori- 
 ginal odour of the wood. 
 
 Cyrtostyle, a circular projecting por- 
 tico. 
 
 Cyzicenus, anciently a hall decorated 
 with sculpture. 
 
DAC 
 
 DAGUERREOTYPE. 
 
 DAT 
 
 13. 
 
 DACTYLUS, a Greek measure of 
 length, the sixteenth part of an 
 
 / English foot. 
 
 Dado, a terra for the die or plane 
 face of a pedestal. The dado em- 
 ployed in the interior of buildings 
 is a continuous pedestal, with a 
 plinth and base moulding, and a 
 cornice or dado moulding sur- 
 
 . mounting the die. 
 'Dado, the solid block or cube forming 
 the body of a pedestal, in classical 
 architecture, between the base 
 mouldings and cornice; an archi- 
 tectural arrangement of mouldings, 
 etc., round the lower part of the 
 wails of a room. 
 
 Dagger, in ship-building, a piece of 
 timber that crosses all the poppets 
 of the bulge-ways, to keep them 
 together: the plank that secures 
 the heads of the poppets is called 
 the dagger-plank. 
 
 Dagger knees are lodging knees, with 
 side arms cast down and bolted 
 through the clamp : they are placed 
 at the lower decks of some ships, 
 instead of hanging knees, to pre- 
 serve as much stowage in the hold 
 as possible. 
 
 Daguerreotype, sun drawing ; na- 
 ture's drawing by the aid of light. 
 It was the invention of two French- 
 men, M. Daguerre and M. Niepce. 
 The invention consists of the fix- 
 ation of the images formed on the 
 focus of the camera-obscura ; is 
 made on very smooth surfaces of 
 pure silver plated on copper. 
 
 Dairy-house, a place for keeping milk. 
 
 Dais, in early domestic architecture, 
 the chief seat at the high board or 
 principal table (cross-table) in a 
 baronial hall ; also the principal 
 table itself, and the raised part of 
 the floor on which it is placed. 
 
 Dais, a canopy to cover an altar, 
 throne, or tribunal ; the chief or 
 upper table in a monastery. 
 
 Dam, a bank or obstruction built 
 across a river or stream, for the 
 
 137 
 
 purpose of raising the level of the 
 water on the opposite side of it. 
 Dams built for the purpose of in- 
 land navigation, or for that of se- 
 curing a water power, may be con- 
 sidered as having a more permanent 
 character. 
 
 Damascus steel, a sort of steel brought 
 from the Levant, greatly esteemed 
 for the manufacture of cutting in- 
 struments. 
 
 Damasquine, a term applied to orna- 
 mental work of gold or silver, in- 
 crusted on iron or steel. 
 
 Damonico or Monicon, an iron ochre, 
 being a compound of terra di sienna 
 and Roman ochre, burnt, and hav- 
 ing all their qualities : it is rather 
 more russet in hue than the orange 
 de Mars, has considerable transpa- 
 rency, is rich and durable in colour, 
 and affords good flesh tints. 
 
 Damper, a valve placed in a chimney, 
 to diminish the draught when the 
 heat is too intense. 
 
 Damper, in locomotive engines, a kind 
 of iron Venetian blind, fixed to the 
 smoke-box end of the boiler, in 
 front of the tubes : it is shut down 
 when the engine is standing, and 
 thus stops the draught and econo- 
 mizes fuel ; but it is opened when 
 the engine is running. 
 
 Damps : various kinds of permanently 
 elastic fluids generated in mines 
 are thus named by the miners : 
 choke-damps consist mostly of 
 carbonic acid gas, and fire-damps 
 of carburetted hydrogen gas. 
 
 Dancette, in heraldry, zigzag or 
 chevron fret ; seen in Norman 
 buildings. 
 
 Dark ages were periods when the 
 monks and ecclesiastics were the 
 only learned persons : when reli- 
 gion, law, politics, and physics were 
 administered and controlled by the 
 clergy, denominated clerks. 
 
 Data useful in various calculations of 
 the properties of materials. [The 
 data correspond to the mean tern- 
 
DAT 
 
 DATA. 
 
 DAT 
 
 perature and pressure of the atmo- 
 sphere ; the materials are assumeti 
 to be dry, and the temperature is 
 measured by Fahrenheit's scale.] 
 
 AIR. Specific gravity, 0-0012; 
 weight of a cubic foot, 0-0753 Ibs., 
 or 527 grains (Shuckburgh) ; 13"3 
 cubic feet, or 17 cylindric feet of 
 air, weigh 1 Ib. ; it expands -^-^ or 
 00208 of its bulk at 32 by the 
 addition of one degree of heat. 
 (Dulong and Petit.) 
 
 ASH. Specific gravity, 0'76 ; 
 weight of a cubic foot, 47'51bs.; 
 weight of a bar 1 foot long and 1 
 inch square, 0'33 Ibs. ; will bear 
 without permanent alteration a 
 strain of 3540 Ibs. upon a square 
 inch, and an extension of -^^ of its 
 length ; weight of modulus of elas- 
 ticity for a base of an inch square, 
 1,640,000 Ibs. ; height of modulus 
 of elasticity, 4,970,000 feet ; mo- 
 dulus of resilience, 7'6 ; specific 
 resilience, 10. (Calculated from 
 Barlow's experiments.) 
 
 Compared with cast iron as unity, 
 its strength is 0'23 ; its extensibi- 
 lity, 2-6 ; and its stiffness, 0-089. 
 
 ATMOSPHERE. Mean pressureof, 
 at London, 28'89 inches of mercury 
 = 14-18 Ibs. upon a square inch. 
 (Royal Society.) The pressure of 
 the atmosphere is usually estimated 
 at 30 inches of mercury, which is 
 very nearly 13f Ibs. upon a square 
 inch, and equivalent to a column 
 of water 34 feet high. 
 
 BEECH. Specific gravity, 0'696 ; 
 weight of a cubic foot, 45'3 Ibs. ; 
 weight of a bar 1 foot long and 
 1 inch square, 0'3151b. ; will bear 
 without permanent alteration on a 
 square inch, 2360 Ibs., and an ex- 
 tension of -g-^y of its length ; weight 
 of modulus of elasticity for a base 
 of an inch square, 1, 345,000 Ibs. ; 
 height of modulus of elasticity, 
 4,600,000 feet; modulus of resi- 
 lience, 4-14 ; specific resilience, 6. 
 (Calculated from Barlow's Experi- 
 ments.) 
 
 Compared with cast iron as unity, 
 its strength is 0*15 ; its extensi- 
 
 bility, 2-1 ; and its stiffness, 0'073. 
 
 BRASS, cast. Specific gravity, 
 8.37 ; weight of a cubic foot, 
 523 Ibs.; weight of a bar 1 foot long 
 and 1 inch square, 3'63 Ibs. ; ex- 
 pands -5^0-77 of its length by one 
 degree of heat (Troughton) ; melts 
 at 1869 (Daniell); cohesive force 
 of a square inch, 18,000 Ibs. (Ren- 
 nie); will bear on a square inch 
 without permanent alteration, 
 6700 Ibs., and an extension in 
 length of rgVa > weight of modulus 
 of elasticity for a base of an inch 
 square, 8,930,000 Ibs.; height of 
 modulus of elasticity, 2,406,000 
 feet ; modulus of resilience, 5 ; 
 specific resilience, - 6. (Tredgold). 
 
 Compared with cast iron as unity, 
 its strength is 0-435 ; its extensi- 
 bility, 0-9; and its stiffness, 0-49. 
 
 BRICK. Specific gravity, 1 841 ; 
 weight of a cubic foot, 115 Ibs. ; 
 absorbs -^ of its weight of water ; 
 cohesive force of a square inch, 
 275 Ibs. (Tredgold) ; is crushed by 
 a force of 562 Ibs. on a square 
 inch (Rennie.) 
 
 BRICK-WORK. Weight of a cubic 
 foot of newly built, 117 Ibs.; 
 weight of a rod of new brick-work, 
 16 tons. 
 
 BRIDGES. When a bridge is 
 covered with people, it is about 
 equivalent to a load of 1 20 Ibs. on 
 a superficial foot ; and this may be 
 esteemed the greatest possible ex- 
 traneous load that can be collected 
 on a bridge; while one incapable 
 of supporting this load cannot be 
 deemed safe. 
 
 BRONZE. See Gun-metal. 
 
 CAST IRON. Specific gravity, 
 7*207 ; weight of a cubic foot, 
 450 Ibs. ; a bar 1 foot long and 1 
 inch square weighs 3'21bs. nearly; 
 it expands y^Wo of its len g tn b V 
 one degree of heat (Roy) ; greatest 
 change of length in the shade in 
 this climate, TT V? greatest change 
 of length when exposed to sun's 
 rays, -^y^; melts at 3479 (Da- 
 niell), and shrinks in cooling from 
 ' ff to ^ of its length (Muschet); 
 
 138 
 
DAT 
 
 DATA. 
 
 DAT 
 
 is crushed by a force of 93,000 Ibs. 
 upon a square inch (Rennie) ; will 
 bear without permanent alteration 
 15,300 Ibs. upon a square inch, and 
 an extension of -j-oV* of its length ; 
 weight of modulus of elasticity, for 
 abase 1 inch square, 18, 400,0001bs.; 
 height of modulus of elasticity, 
 5,750,000 feet ; modulus of resi- 
 lience, 127; specific resilience, 
 1-76. (Tredgold.) 
 
 CHALK. Specific gravity, 2-315 ; 
 weight of a cubic foot, 144'7 Ibs. ; 
 is crushed by a force of 500 Ibs. on 
 a square inch. (Rennie.) 
 
 CLAY. Specific gravity, 2'0 ; 
 weight of a cubic foot, 125 Ibs. 
 
 COAL, Newcastle. Specific gra- 
 vity, 1-269 ; weight of a cubic foot, 
 79'31 Ibs. A London chaldron of 
 36 bushels weighs about 28 cwt., 
 whence a bushel is 87 Ibs. (but is 
 usually rated at 84 Ibs.) A New- 
 castle chaldron, 53 cwt. (Smea- 
 ton.) 
 
 COPPER. Specific gravity, 8'75 
 (Hatchett) ; weight of a cubic foot, 
 549 Ibs. ; weight of a bar 1 foot 
 long and 1 inch square, 3'811bs. ; 
 expands in length by one degree of 
 heat, 7 os T 5 o (Smeaton) ; melts at 
 2548 (Daniell) ; cohesive force of 
 a square inch, when hammered, 
 33,000 Ibs. (Rennie.) 
 
 EARTH, common. Specific gra- 
 vity, 1-52 to 2-00; weight of a 
 cubic foot, from 95 to 125 Ibs. 
 
 ELM. Specific gravity, 0-544 ; 
 weight of a cubic foot, 34 Ibs. ; 
 weight of a bar 1 foot long and 1 
 inch square, 0-236 Ibs.; will bear on 
 a square inch without permanent 
 alteration, 3240 Ibs., and an ex- 
 tension in length of -^\-^ ; weight 
 of modulus of elasticity for a base 
 of an inch square, 1,340,000 Ibs. ; 
 height of modulus of elasticity, 
 5, 680, 000 -feet ; modulus of resi- 
 lience, 7 '8 7 ; specific resilience, 
 14-4. (Calculated from Barlow's 
 Experiments.) 
 
 Compared with cast iron as unity, 
 its strength is 0-21 ; its extensi- 
 bility, 2-9 ; and its stiffness, 0*073. 
 
 FIR, red or yellow. Specific gra- 
 vity, 0'557 ; weight of a cubic foot, 
 34-8 Ibs. ; weight of a bar 1 foot 
 long and 1 inch square, 0*242 Ib. ; 
 will bear on a square inch without 
 permanent alteration, 4290 Ibs. = 
 2 tons nearly, and an extension in 
 length of T f n ; weight of modulus 
 of elasticity for a base of an inch 
 square, 2,016, 000 Ibs. ; height of 
 'modulus of elasticity, 8,330,000 
 feet; modulus of resilience, 9'13; 
 its specific resilience, 16'4. (Tred- 
 gold.) 
 
 Compared with cast iron as unity, 
 its strength is 0'3 ; its extensibility, 
 2-6, and its stiffness, 0'1154,= 
 
 ** 
 
 FIR, white. Specific gravity, 0-47; 
 weight of a cubic foot, 29'3 Ibs. ; 
 weight of a bar 1 foot long and 
 1 inch square, 0-204 Ib. ; will bear 
 on a square inch without perma- 
 nent alteration, 3630 Ibs., and an 
 extension in length of -5-^ ; weight 
 of modulus of elasticity for a base 
 of an inch square, 1,830,000 Ibs. ; 
 height of modulus of elasticity, 
 8,970,000 feet; modulus of resi- 
 lience, 7'2 ; specific resilience, 15'3. 
 (Tredgold.) 
 
 Compared with cast iron as unity, 
 its strength is 0-23 ; its extensibi- 
 lity, 2-4 ; and its stiffness, 0-1. 
 
 FLOORS. The weight of a super- 
 ficial foot of a floor is about 40 Ibs. 
 when there is a ceiling, counter- 
 floor, and iron girders. When a 
 floor is covered with people, the 
 load upon a superficial foot may be 
 calculated at 120 Ibs. : therefore, 
 1 20 + 40 = 160 Ibs. on a superficial 
 foot is the least stress that ought to 
 be taken in estimating the strength 
 for the parts of a floor of a room. 
 
 FORCE. See Gravity, Horse, etc. 
 
 GRANITE, Aberdeen. Specific 
 gravity, 2'625 ; weight of a cubic 
 foot, 164 Ibs. ; is crushed by a force 
 of 10-910 Ibs. upon a square inch. 
 (Rennie.) 
 
 GRAVEL. Weight of a cubic 
 foot, about 120 Ibs. 
 
 GRAVITY generates a velocity 
 
 139 
 
DAT 
 
 DATA. 
 
 DAT 
 
 of 32 feet in a second in a body 
 falling from rest ; space described 
 in the first second, 16 T ^ feet. 
 
 GUN-METAL, cast (copper 8 
 parts, tin 1). Specific gravity, 
 8-153; weight of a cubic foot, 
 509^ Ibs. ; weight of a bar 1 foot 
 long and 1 inch square, 3'54 Ibs. 
 (Tredgold) ; expands in length by 
 1 of heat, TO^OT (Smeaton) ; will 
 bear on a square inch without pe'r- 
 manent alteration, 10, 000 Ibs., and 
 an extension in length of ^^ ; 
 weight of modulus of elasticity for 
 a base 1 inch square, 9,873,000 Ibs. ; 
 height of modulus of elasticity, 
 2,790,000 feet; modulus of resi- 
 lience, and specific resilience, not 
 determined. (Tredgold.) 
 
 Compared with cast iron as unity, 
 its strength is 0'65 ; its extensibi- 
 lity, 1-25 ; and its stiffness, 0-535. 
 
 HORSE, of average power, pro- 
 duces the greatest effect in draw- 
 ing a load when exerting a force 
 of 187^ Ibs. with a velocity of 2 
 feet per second, working 8 hours 
 in a day. (Tredgold.) A good 
 horse can exert a force of 480 Ibs. 
 for a short time. (Desaguliers.) 
 .., In calculating the strength for 
 horse machinery, the horse's power 
 should be considered 400 Ibs. 
 
 IRON, cast. See Cast Iron. 
 
 Iron, malleable. Specific gravity, 
 7"6 (Muschenbroek) ; weight of a 
 cubic foot, 475 Ibs. ; weight of a 
 bar 1 foot long and 1 inch square, 
 3-3 Ibs. ; ditto, when hammered, 
 3-4 Ibs.; expands in length by 1 of 
 heat, TroVuo (Smeaton); good 
 English iron will bear on a square 
 inch without permanent alteration, 
 17, 800 Ibs. = 8 tons nearly, and an 
 extension in length of 1-4 00 ; cohe- 
 sive force diminished -g^ 1 ^ by an 
 elevation 1 of temperature ; weight 
 of modulus of elasticity for a base 
 of an inch square, 24,920,000 Ibs. ; 
 height of modulus of elasticity, 
 7,550,000 feet ; modulus of resi- 
 lience, and specific resilience, not 
 determined. (Tredgold.) 
 
 Compared with cast iron as unity, 
 
 140 
 
 its strength is T12 ; its extensibi- 
 lity, 0-86 ; and its stiffness, 1-3- 
 
 LARCH. Specific gravity, -500 ; 
 weight of a cubic foot, 35 Ibs. ; 
 weight of a bar 1 foot long and 
 1 inch square, 0-243 Ib. ; will bear 
 on a square inch without perma- 
 nent alteration, 2065 Ibs., and an 
 ^extension in length of -^-^ ; weight 
 of modulus of elasticity for a base 
 of an inch square, 10,074,000 Ibs. : 
 height of modulus of elasticity, 
 4,415,000 feet; modulus of resi- 
 lience, 4; specific resilience, 7'1. 
 (Calculated from Barlow's Experi- 
 ments.) 
 
 Compared with cast iron as unity, 
 its strength is 0-136; its extensi- 
 bility, 2-3 ; and its stiffness, 0-058. 
 
 LEAD, cast. Specific gravity, 
 11 '353 (Brisson); weight of a 
 cubic foot, 709'5 Ibs.; weight of a 
 bar 1 foot long and 1 inch square, 
 4-94 Ibs.; expands in length by 1 
 degree of heat, -^^ (Smeaton) ; 
 melts at 612 (Crichton) ; will 
 bear on a square inch without per- 
 manent alteration, 1500 Ibs., and 
 an extension in length of -5^; 
 weight of modulus of elasticity for 
 a base 1 inch square, 720, 000 Ibs. ; 
 height of modulus of elasticity, 
 146,000 feet; modulus of resi- 
 lience, 3-12; specific resilience, 
 0-27 (Tredgold). 
 
 Compared with cast iron as unity, 
 its strength is 0-096 ; extensi- 
 bility, 2-5; and its stiffness, 0'0385. 
 
 MAHOGANY, Honduras. Specific 
 gravity, 0'56 ; weight of a cubic 
 foot, 35 Ibs. ; weight of a bar 1 foot 
 long and 1 inch square, 0'243 Ib. ; 
 will bear on a square inch without 
 permanent alteration, 3800 Ibs., 
 and an extension in length of ^^ ; 
 weight of modulus of elasicity for 
 a base 1 inch square, 1,596,000 Ibs.; 
 height of modulus of elasticity, 
 6,570,000 feet; modulus of resi- 
 lience, 9-047 ; specific resilience, 
 16-1. (Tredgold.) 
 
 Compared with cast iron as unity, 
 its strength is 0-24 ; its extensibi- 
 lity, 2-9 ; and its stiffness, 0'487. 
 
DAT 
 
 DATA. 
 
 DAT 
 
 MAN. A man of average power 
 produces the greatest effect when 
 exerting a force of 31i Ihs. with a 
 velocity of 2 feet per second, for 
 10 hours in a day. (Tredgold.) A 
 strong man will raise and carry 
 from 250to3001bs. (Desaguliers.) 
 
 MARBLE, white. Specific gra- 
 vity, 2-706; weight of a cubic foot, 
 169 Jbs; weight of a bar 1 foot 
 long and 1 inch square, 1*1 7 lb. ; 
 cohesive force of a square inch, 
 1811 Ibs. ; extensibility, -3^ of its 
 length ; weight of modulus of elas- 
 ticity for a base of an inch square, 
 2,520,000 Ibs. ; height of modulus 
 of elasticity, 2,150^000 feet ; mo- 
 dulus of resilience at the point of 
 fracture, 1"3 ; specific resilience at 
 the point of fracture, 0'48 (Tred- 
 gold) ; is crushed by a force of 
 6060 Ibs. upon a square inch 
 (Rennie). 
 
 MERCURY. Specific gravity, 
 13'568 (Brisson) ; weight of a 
 cubic inch, 0'4948 lb. ; expands in 
 bulk by 1 of heat, ^^ (Dnlong 
 and Petit) ; weight of modulus of 
 elasticity for a base of an inch 
 square, 4,417,000 Ibs. ; height of 
 modulus of elasticity, 750,000 feet. 
 (Dr. Young, from Canton's Experi- 
 ments.) 
 
 OAK, good English. Specific 
 gravity, 0'83; weight of a cubic 
 foot, 52 Ibs. ; weight of a bar 1 foot 
 long and 1 inch square, 0'36 lb. ; 
 will bear upon a square inch with- 
 out permanent alteration, 3960 Ibs., 
 and an extension in length of -^-^ ; 
 weight of modulus of elasticity for 
 abase 1 inch square, 1,7 00,000- Ibs.; 
 height of modulus of elasticity, 
 4,730,000 feet; modulus of resi- 
 lience, 9'2; specific resilience, 11. 
 (Tredgold.) 
 
 Compared with cast iron as unity, 
 its strength is 0*25 ; its extensibi- 
 lity, 2'8 ; and its stiffness, 0-093. 
 
 PENDULUM. Length of pendu- 
 lum to vibrate seconds in the lati- 
 tude of London, 39-1372 inches 
 (Kater) ; ditto to vibrate half- 
 seconds, 9'7843 inches. 
 
 141 
 
 PINE, American yellow. Specific 
 gravity, 0'46 ; weight of a cubic 
 foot, 26 Ibs. ; weight of a bar 
 1 foot long and one inch square, 
 0-186 lb. ; will bear on a square 
 inch without permanent alteration, 
 3900 Ibs., and an extension in length 
 of 7Ti: 5 weight of modulus of elas- 
 ticity for a base of an inch square, 
 1, 600,000 Ibs. ; height of modulus 
 of elasticity, 8,700,000 feet; mo- 
 dulus of resilience, 9'4 ; specific 
 resilience, 20. (Tredgold.) 
 
 Compared with cast iron as 
 unity, its strength is 0'25 ; its ex- 
 tensibility, 2'9 ; and its stiffness, 
 0-087. 
 
 PORPHYRY, red. Specific gra- 
 vity, 2*871 ; weight of a cubic foot, 
 179 Ibs. ; is crushed by a force of 
 35, 568 Ibs. upon a square inch. 
 (Gauthey.) 
 
 ROPE, hempen. Weight of a 
 common rope 1 foot long and 1 
 inch in circumference, from 0*04 
 to 0'46 lb. ; and a rope of this size 
 should not be exposed to a strain 
 greater than 200 Ibs. ; but in com- 
 pounded ropes, such as cables, the 
 greatest strain should exceed 
 120 Ibs. ; and the weight of a ca- 
 ble 1 foot in length and 1 inch 
 in circumference does not exceed 
 0'027 lb. The square of the circum- 
 ference in inches multiplied by 
 200 will give the number of pounds 
 a rope may be loaded with ; and 
 multiply by 120 instead of 200 for 
 cables. Common ropes will bear a 
 greater load with safety after they 
 have been some time in use, in con- 
 sequence of the tension of the fibres 
 becoming equalized by repeated 
 stretchings and partial untwisting. 
 It has been imagined that the im- 
 proved strength was gained by 
 their being laid up in store ; but if 
 they can there be preserved from 
 deterioration, it is as much as can 
 be expected. 
 
 ROOFS. Weight of a square foot of 
 Welsh rag slating, 11^ Ibs. ; weight 
 of a square foot of plain tiling, 
 16 Ibs. ; greatest force of the wind 
 
DAT 
 
 DATA. 
 
 DAT 
 
 upon a superficial foot of roofing 
 may be estimated at 40 Ibs. 
 
 SLATE, Welsh. Specific gavity, 
 2752 (Kirwan) ; weight of a cubic 
 foot, 1 72 Ibs. ; weight of a bar 1 foot 
 long and 1 inch square, 1-19 lb.; 
 cohesive force of a square inch, 
 1 1,500 Ibs. ; extension before frac- 
 ture, y^^-o ; weight of modulus of 
 elasticity for abase of an inch square, 
 15,800,000 Ibs. ; height of modulus 
 of elasticity, 13,240,000 feet ; mo- 
 dulus of resilience, 8-4 ; specific re- 
 silience, 2 (Tredgold). 
 
 SLATE, Westmoreland. Cohe- 
 sive force of a square inch, 7870 Ibs.; 
 extension in length before fracture, 
 __i__ ; weight of modulus of elas- 
 ticity for a base of an inch square, 
 12,900,000 Ibs. (Tredgold.) 
 
 SLATE, Scotch. Cohesive force 
 of a square inch, 9600 Ibs. ; exten- 
 sion in length before fracture, Y^J? 
 weight of modulus of elasticity for a 
 base 1 inch square, 15, 790,000 Ibs. 
 (Tredgold.) 
 
 STEAM. Specific gravity at 212 
 is to that of air at the mean tem- 
 perature as 0-472 is to 1 (Thomson); 
 weight of a cubic foot, 249 grains ; 
 modulus of elasticity for a base of 
 an inch square, 14f Ibs. ; when not 
 in contact with water, expands 
 _!_ of its bulk by 1 of heat (Gay- 
 Lussac). 
 
 STEEL. Specific gravity, 7*84 ; 
 weight of a cubic foot, 490 Ibs. ; a 
 bar I foot long arid 1 inch square 
 weighs 3'4 Ibs.; it expands in length 
 by 1 of heat, -^srinro (R5 r ) > tem - 
 pered steel will bear without per- 
 manent alteration, 45,000 Ibs.; co- 
 hesive force of a square inch, 
 130, 000 Ibs. (Rennie); cohesive 
 force diminished -g.^^ by elevating 
 the temperature 1 ; modulus of 
 elasticity for a base of an inch 
 square, 29,000,000 Ibs. ; height of 
 modulus of elasticity, 8,530,000 
 feet. (Dr. Young.) 
 
 STONE, Portland. Specific gra- 
 vity, 2~ 113; weight of a cubic foot, 
 132 Ibs. ; weight of a prism 1 inch 
 square and 1 foot long, 0-92 lb.; 
 
 absorbs T ^ of its weight of water 
 (R. Tredgold) ; is crushed by a 
 force of 3729 Ibs. upon a square 
 inch (Rennie); cohesive force of a 
 square inch, 857 Ibs. ; extends be- 
 fore fracture yrW ^ ^ ts l en g tn ; 
 modulus of elasticity for a base of 
 an inch square, 1,533,000 Ibs. ; 
 height of modulus of elasticity, 
 1,672,000 feet ; modulus of resi- 
 lience at the point of fracture, 
 0'5 ; specific resilience at the point 
 of fracture, 0-23. (Tredgold.) 
 
 STONE, Bath. Specific gravity, 
 T975 ; weight of a cubic foot, 
 123-4 Ibs. ; absorbs ^ of its weight 
 of water (R. Tredgold) ; cohesive 
 force of a square inch, 478 Ibs. 
 (Tredgold.) 
 
 STONE, Craigleith. Specific gra- 
 vity, 2-362 ; weight of a cubic foot 
 147-6 Ibs. absorbs $ of its weight 
 of water; cohesive force of a square 
 inch, 772 Ibs. (Tredgold); is crushed 
 by a force of 5490 Ibs. upon a square 
 inch (Rennie). 
 
 STONE, Dundee. Specific gra- 
 vity, 2-621 ; weight of a cubic foot, 
 163-8 Ibs; absorbs ?TT part of its 
 weight of water ; cohesive force of 
 a square inch, 2661 Ibs. (Tredgold); 
 is crushed by a force of 6630 Ibs. 
 upon a square inch (Rennie). 
 
 STONE-WORK. Weight of a cubic 
 foot of rubble-work, about 140 Ibs. ; 
 of hewn stone, 160 Ibs. 
 
 TIN, cast. Specific gravity, 7*291 
 (Brisson) ; weight of a cubic foot, 
 455-7 Ibs. ; weight of a bar 1 foot 
 long and 1 inch square, 3'165 Ibs. ; 
 expands in length by 1 of heat, 
 T-ii-nr (Smeaton) ; melts at 442 
 (Crichton) ; will bear upon a square 
 inch without permanent alteration, 
 2880 Ibs., and an extension in 
 length of Y^Vu ; modulus of elas- 
 ticity for a base of an inch square, 
 4,608,000; height of modulus of 
 elasticity, 1,453, 000 feet ; modulus 
 of resilience, 1-8; specific resili- 
 ence, 0-247 (Tredgold). 
 
 Compared with cast iron as unity, 
 its strength is 0'182 ; its extensibi- 
 lity, 0-75 ; and its stiffness, 0'25. 
 
 142 
 
DAT 
 
 DEAD COLOURING. 
 
 DEA 
 
 WATER, river. Specific gravity, 
 1-000 ; weight of a cubic foot, 
 62-5 Ibs. ; weight of a cubic inch, 
 252-525 grains ; weight of a prism 
 1 foot long and 1 inch square, 
 0-434 Ib. ; weight of an ale gallon 
 of water, 10'2 Ibs. ; expands in bulk 
 by 1 of heat, ^^ (Dalton) ; ex- 
 pands in freezing, T r T of its bulk 
 (Williams) ; and the expanding 
 force of freezing water is about 
 35,000 Ibs. upou a square inch, ac- 
 cording to Muschenbroek's valua- 
 tion ; modulus of elasticity for a 
 base of an inch square, 326,0001bs.; 
 height of modulus of elasticity, 
 750,000 feet, or 22,100 atmo- 
 spheres of 30 inches of mercury. 
 (Dr. Young, from Canton's Expe- 
 riments.) 
 
 Water has a state of maximum 
 density at or near 40, which is con- 
 sidered an exception to the general 
 law of expansion by heat : it is 
 extremely improbable that there 
 is anything more than an apparent 
 exception, most likely arising from 
 water at low temperatures absorb- 
 ing a considerable quantity of air, 
 which has the effect of expanding 
 it, and consequently of causing the 
 apparent anomaly. 
 
 WATER, sea. Specific gravity, 
 1-0271; weight of a cubic foot, 
 64-2 Ibs. 
 
 WATER is 828 times the density 
 of air of the temperature 60, and 
 barometer 30. 
 
 WHALE-BONE. Specific gravity, 
 1 -3 ; weight of a cubic foot, 8 1 Ibs. ; 
 will bear a strain of 5600 Ibs. upon 
 a square inch without permanent 
 alteration, and an extension in 
 
 length of 
 
 modulus of elas- 
 
 ticity for a base of an inch square, 
 820,000 Ibs. ; height of modulus of 
 elasticity, 1,458,000 feet; modulus 
 of resilience, 38-3 ; specific resili- 
 ence, 29. (Tredgold.) 
 
 WIND. Greatest observed ve- 
 locity, 159 feet per second (Ro- 
 chon) ; force of wind with that ve- 
 locity, about 57:| Ibs. on a square 
 foot. 
 
 143 
 
 ZINC cast. Specific gravity, 
 7-028 (Watson) ; weight of a cubic 
 foot, 439lbs; weight of a bar 
 1 inch square and 1 foot long, 
 3-05 Ibs. ; expands in length by 1 
 of heat, ^Y^J^ (Smeaton) ; melts 
 at 648 (Daniell); will bear on a 
 square inch without permanent al- 
 teration, 5700 Ibs. = 0-365 cast 
 iron, and an extension in length 
 
 f Woo = i tna * f cast i ron 
 (Tredgold); modulus of elasticity for 
 a base of an inch square, 13,680,000 
 Ibs. ; height of modulus of elasti- 
 city, 4,480,000 feet; modulus of 
 resilience, 2-4 ; specific resilience, 
 0-34. (Tredgold.) 
 
 Compared with cast iron as unity, 
 its strength is 0'365 ; its extensi- 
 bility, 0-5 ; and its stiffness, 0*76. 
 
 Data, a term for such facts, things, 
 or quantities as are given or known, 
 in order thereby to find other things 
 that are unknown. 
 
 Davit, in navigation, a short boom 
 fitted in the fore channel, to hoist 
 the flukes of the anchor to the 
 bow, which is called ' fishing the 
 anchor.' 
 
 David's -staff, an instrument used in 
 navigation. 
 
 Day, or Bay, in architecture, one of 
 the lights or compartments between 
 mullion and mullion, in the great 
 windows of the pointed style. 
 
 Days, in early domestic architecture, 
 the bay or lights of a window ; the 
 spaces between the mullions. 
 
 Dead colouring is the first layer of 
 colours, consisting usually of some 
 shade of grey. Its design is to 
 receive and preserve the finishing 
 colours ; and it is called dead be- 
 cause it is not seen when the work 
 is completed. 
 
 Dead doors, in ship-building, fitted to 
 the outside of the quarter-gallery 
 doors, in case the quarter-gallery 
 should be carried away. 
 
 Dead eyes, fixed in the channels, with 
 three holes to receive the lanyard 
 of the shrouds. 
 
 Dead fiat, the nameof a midship board 
 
 Dead lights, in navigation, wooden 
 
DE\ 
 
 DECORATION. 
 
 DEC 
 
 shutters for the cabin windows, 
 which are fastened on when fhe 
 sea runs high. 
 
 Dead-men 's-eyes (in a ship), small 
 blocks or pulleys with many holes, 
 but no shivers wherein run the 
 laniers. 
 
 Dead-neap, a low tide. 
 
 Dead reckoning, the estimation which 
 seamen make of the ship's place, 
 by keeping an account of her way 
 by the log, by the course steered, 
 and by rectifying the whole by al- 
 lowance for drift, leeway, etc. 
 
 Dead rising, is that part of the ship 
 that lies aft, between ber keel and 
 floor timbers. 
 
 Dead ropes, ropes which do not run 
 in any block or pulley. 
 
 Deads (among miners), the earth or 
 other fossil substances which en- 
 close the ore on every side. 
 
 Dead shore, a piece of timber worked 
 up in brick-work, to support a su- 
 perincumbeut mass until the brick- 
 work which is to carry it has set or 
 become hard. 
 
 Dead water, the eddy water imme- 
 diately at the stern of a ship while 
 under way. 
 
 Dead wood, pieces of timber fayed 
 on the keel to seat the flow-tim- 
 bers on afore and abaft the floors, 
 and continued as high as the cutting 
 down of the floors. 
 
 Deafening sound-boarding, the pug- 
 ging used to prevent the passage of 
 sound through wooden partitions. 
 
 Dearn, a door-post, or threshold ; to 
 conceal, or shut up. 
 
 Deambulatory, an ambulatory or clois- 
 ter for exercise ; also the aisles of 
 a church, or the porticoes round 
 the body of a church. 
 
 Debacle, a great aqueous torrent, a 
 breaking up and transport of mas- 
 sive rocks and gravel by an enor- 
 mous rush of water. 
 
 Debris, fragments of rocks, boulders, 
 gravel, sand, trunks of trees, etc., 
 detached from the summits and 
 
 sides of mountains by the effect of 
 the elements. 
 
 Decade, the sum of ten. 
 
 Decagon, in geometry, a plain figure 
 of ten sides. 
 
 Decalogue, the Ten Commandments 
 delivered to the Israelites from 
 Mount Sinai, in which the moral 
 law is summarily comprehended. 
 The Jews call these precepts ' The 
 Ten Words.'* In the building of 
 new churches, and in the restora- 
 tion of those of olden times, a pro- 
 per and effective style of painting 
 and embellishing the words of the 
 ten commandments in face of the 
 altar has been introduced. 
 
 Decanicum, an ecclesiastical prison. 
 
 Decastyle, in architecture : a temple 
 is said to be decastyle when its por- 
 tico contains ten columns in aline. 
 
 Decastyle, a portico consisting of ten 
 columns in front. 
 
 Decempeda, a ten-foot rod employed 
 by architects and surveyors for 
 taking measurements. 
 
 Decemremis, a vessel with ten banks 
 of oars on a side. 
 
 Decimal, the tenth part. 
 
 Deck, the floor of a ship. 
 "Decoration, the combination of orna- 
 mental objects which are employed 
 in great variety, principally for the 
 interior and exterior of all kinds 
 of edifices, and for purposes of art 
 generally. Decoration, when judi- 
 ciously introduced, becomes in 
 many instances a language, intel- 
 ligible only, however, when the 
 artist is capable of speaking it 
 correctly and the spectator ol 
 comprehending it. It is then a 
 system of hieroglyphic writing, 
 and the building to which it is ap- 
 plied becomes historical, and tells 
 its tale more nobly and appro- 
 priately than it can ever do through 
 the undignified medium of mural 
 inscriptions. Nothing can be more 
 judicious or appropriate than the 
 sculpture in the metopes and pedi- 
 
 * To these the Saviour added another : " A. new commandment I give unto you, Thai 
 ye love one another ; as I have loved you, that ye also love one another." (John xiii. 34. ] 
 
 144 
 
DEC 
 
 DEFINITIONS IN GEOMETRY. 
 
 DEF 
 
 ment of the Parthenon. Ornament 
 here not only creates a variety on 
 the surface of the work, but re- 
 lates, by the aid of the sculptor, a 
 history intimately connected with 
 the religious and moral destination 
 of the edifice to which it is applied. 
 
 Decorative style of Gothic Architec- 
 ture : first introduced in the reign 
 of Edward I., it was matured in 
 England, and prevailed during the 
 greater part of the 14th century. 
 Its distinguishing features, says Dr. 
 Whewell, are characterized by its 
 window-tracery, geometrical in the 
 early instances, flowing in the 
 later; but also, and perhaps bet- 
 ter, by its triangular canopies, 
 crocketed and finialed ; its niched 
 buttresses, with triangular heads ; 
 its peculiar mouldings, no longer a 
 collection of equal rounds, with 
 hollows like the early English, but 
 an assemblage of various members, 
 some broad, some narrow, beauti- 
 fully grouped and proportioned. A 
 capital with crumpled leaves, a 
 peculiar base and pedestal, also 
 belong to this style. ' 
 
 Definitions in geometry : 
 
 1. A point is that which hath 
 no parts, or which hath no magni- 
 tude. 
 
 2. A line is length without 
 breadth. 
 
 3. A superficies has length and 
 breadth. 
 
 4. A solid is a figure of three di- 
 mensions, having length, breadth, 
 and thickness. Hence surfaces 
 are extremities of solids, and lines 
 the extremities of surfaces, and 
 points the extremities of lines. 
 
 If two lines will always coincide 
 however applied, when any two 
 points in the one coincide with 
 the two points in the other, the 
 two lines are called straight lines, 
 or otherwise right lines. 
 
 A curve continually changes its 
 direction between its extreme 
 points, or has no part straight. 
 
 Parallel lines are always at the 
 same distance, and will never meet, 
 
 145 
 
 though ever so far produced. Ob- 
 lique right lines change their dis- 
 tance, and would meet, if pro- 
 duced. 
 
 One line is perpendicular to an- 
 other when it inclines no more to 
 one side than another. 
 
 A straight line is a tangent to a 
 circle when it touches the circle 
 without cutting, when both are 
 produced. 
 
 An angle is the inclination of 
 
 two lines towards one another in 
 
 the same plane, meeting in a point. 
 
 Angles are either right, acute, 
 
 or oblique. 
 
 A right angle is that which is 
 made by one line perpendicular to 
 another, or when the angles on 
 each side are equal. 
 
 An acute angle is less than a 
 right angle. 
 
 An obtuse angle is greater than 
 a right angle. 
 
 A plane is a surface with which 
 a straight line will everywhere 
 coincide ; and is otherwise called 
 a straight surface. 
 
 Plane figures, bounded by right 
 lines, have names according to the 
 number of their sides, or of their 
 angles, for they have as many sides 
 as angles : the least number is 
 three. 
 
 An equilateral triangle is that 
 whose three sides are equal. 
 
 An isosceles triangle has only 
 two sides equal. 
 
 A scalene triangle has all sides 
 unequal. 
 
 A right-angled triangle has only 
 one right angle. 
 
 Other triangles are oblique- 
 angled, and are either obtuse or 
 acute. 
 
 An acute-angled triangle has all 
 its angles acute. 
 
 An obtuse-angled triangle has 
 one obtuse angle. 
 
 A figure of four sides, or angles, 
 is called a quadrilateral, or quad- 
 rangle. 
 
 A parallelogram is a quadrilate- 
 ral, which has both pairs of its 
 
DEF 
 
 DEFINITIONS IN GEOMETRY. 
 
 DEF 
 
 opposite sides parallel, and takes 
 the following particular names : * 
 
 A rectangle is a parallelogram, 
 having all its angles right ones. 
 
 A square is an equilateral rect- 
 angle, having all its sides equal, 
 and all its angles right angles. 
 
 A rhombus is an equilateral 
 parallelogram whose angles are 
 oblique. 
 
 A rhomboid is an oblique-angled 
 parallelogram, and its opposite sides 
 only are equal. 
 
 A trapezium is a quadrilateral, 
 which has neither pair of its sides 
 parallel. 
 
 A trapezoid has only one of its 
 sides parallel. 
 
 Plane figures, having more than 
 four sides, are in general called 
 polygons, and receive other parti- 
 cular names according to the num- 
 ber of their sides or angles. 
 
 A pentagon is a polygon of five 
 sides, a hexagon of six sides, a hep- 
 tagon seven, an octagon eight, an 
 enneagon nine, a decagon ten, an 
 undecagon eleven, and a dodecagon 
 twelve sides. 
 
 A regular polygon has all its 
 sides and its angles equal ; and if 
 they are not equal, the polygon is 
 irregular. 
 
 An equilateral triangle is also a 
 regular figure of three side?, and 
 a square is one of four ; the former 
 being called a trigon, and the latter 
 a tetragon. 
 
 A circle is a plane figure, 
 bounded by a curve line, called 
 the circumference, which is every- 
 where equidistant, from a certain 
 point within, called its centre. 
 
 The radius of a circle is a right 
 line drawn from the centre to the 
 circumference. 
 
 A diameter of a circle is a right 
 line drawn through the centre, 
 terminating on both sides of the 
 circumference. 
 
 An arc of a circle is any part of 
 the circumference. 
 
 A chord is a right line joining 
 the extremities of an arc. 
 
 146 
 
 A segment is any part of a circle 
 bounded by an arc and its chord. 
 
 A semicircle is half a circle, or 
 a segment cut off by the diameter. 
 
 A sector is any part of a circle 
 bounded by an arc, and two radii 
 drawn to its extremities. 
 
 A quadrant, or quarter of a cir- 
 cle, is a sector having a quarter 
 part of the circumference for its arc, 
 and the two radii perpendicular to 
 each other. 
 
 The height or altitude of any 
 figure is a perpendicular let fall 
 from an angle or its vertex to the 
 opposite side, called the base. 
 
 The measure of any right-lined 
 angle is an arc of any circle con- 
 tained between the two lines which 
 form the angle, the angular point 
 being the centre. 
 
 A solid is said to be cut by a 
 plane when it is divided into two 
 parts, of which the common sur- 
 face of separation is a plane, and 
 this plane is called a section. 
 Definitions of solids : 
 
 A prism is a solid, the ends of 
 which are similar and equal paral- 
 lel planes and the sides parallelo- 
 grams. 
 
 If the ends of the prism are per- 
 pendicular to the sides, the prism 
 is called a right prism. 
 
 If the ends of the prism are 
 oblique to the sides, the prism is 
 called an oblique prism. 
 
 If the ends and sides are equal 
 squares, the prism is called a cube. 
 
 If the base or ends are paral- 
 lelograms, the solid is called a 
 parallelopiped. 
 
 If the bases and sides are rect- 
 angles, the prism is called a rect- 
 angular prism. 
 
 If the ends are circles, the prism 
 is called a cylinder. 
 
 If the ends or bases are ellipses, 
 the prism is called a cylindroid. 
 
 A solid, standing upon any plane 
 figure for its base, the sides of 
 which are plane triangles, meeting 
 in one point, is called a pyramid. 
 
 The solid is denominated from 
 
DEF 
 
 DEGREE. 
 
 DEM 
 
 its base, as a triangular pyramid 
 is one upon a triangular base, a 
 square pyramid one upon a square 
 base, etc. 
 
 If the base is a circle or an ellip- 
 sis, then the pyramid is called a 
 cone. 
 
 If a solid be terminated by two 
 dissimilar parallel planes as ends, 
 and the remaining surfaces joining 
 the ends be also planes, the solid 
 is called a prismoid. 
 
 If a part of a pyramid next to 
 the vertex be cut off by a plane 
 parallel to the base, the portion of 
 the pyramid contained between the 
 cutting plane and the base is called 
 the frustum of a pyramid. 
 
 A solid, the base of which is a 
 rectangle, the four sides joining the 
 base plane surfaces, and two oppo- 
 site ones meeting in a line parallel 
 to the base, is called a cuneus or 
 wedge. 
 
 A solid terminated by a surface 
 which is everywhere equally dis- 
 tant from a certain point within 
 it is called a sphere or globe. 
 
 If a sphere be cut by any two 
 planes, the portion contained be- 
 tween the planes is called a zone, 
 and each of the parts contained by 
 a plane and the curved surface is 
 called a segment. 
 
 If a semi-ellipsis, having an axis 
 for its diameter, be revolved round 
 this axis until it come to the place 
 whence the motion began, the solid 
 formed by the circumvolution is 
 called a spheroid. 
 
 If the spheroid be generated 
 round the greater axis, the solid is 
 called a prolate spheroid. 
 
 If the solid be generated round 
 the lesser axis, the solid is called 
 an oblate spheroid. 
 
 A solid of any of the above 
 structures, hollow within, so as to 
 contain a solid of the same struc- 
 ture, is called a hollow solid. 
 Deflayrator, an instrument for pro- 
 ducing intense light and heat. 
 Deflection, a term applied to the dis- 
 tance by which a curve departs 
 
 from another curve, or from, a 
 straight line. 
 
 Deflection, the deviation of a ship 
 from its course. 
 
 Degree, the 360th part of the circum- 
 ference of a circle ; 60 geographical 
 miles. 
 
 Degree, consisting of three figures of 
 three places, comprehending units, 
 tens, and hundreds. 
 
 Delen (Derk Von) painted temples, 
 saloons, and colonnades, and was a 
 perfect master of architectural em- 
 bellishment. 
 
 De VOrme (Philibert) claims the ho- 
 nour of inventing the volute now 
 most commonly used, and com- 
 plains that others pretend to it 
 because Palladio and Serlio have 
 spoken of it before him. 
 
 DeliqnifE, according toYitruvius, gut- 
 ters, or drains. 
 
 Delivery valve, the upper valve in 
 the air-pump, or that through 
 which the water is lifted into the 
 hot well ; also used when speaking 
 of any sort of pump. 
 
 Delphica, a table made of marble or 
 bronze, and resembling a tripod. 
 
 Delving, to dig. 
 
 Delubrum, a font or baptismal basin. 
 In antiquity, a church, chapel, 
 temple, or consecrated place. Also 
 that part of a Roman temple in 
 which the altar or statue of the 
 deity was erected. 
 
 Demesne, lands belonging to the lord 
 of a manor, and which are conti- 
 , guous to the manor-house. 
 ^Demi-relievo, in sculpture, half-raised 
 figures from the plane, as if cut 
 in two, and only half fixed to the 
 plane. 
 
 Demi-tint is that shade seen when 
 the sun shines on a house, or any 
 other object, making an angle of 
 nearly 45 on the ground plane, or 
 when it shines more on the front 
 than on the end. 
 
 Dendrometer, an instrument for the 
 measuring of trees. 
 
 Dendiculus, a member in the Ionic 
 and Corinthian entablatures, occur- 
 ring between the zophorus and 
 
 147 H 2 
 
DEN 
 
 DERRICK. 
 
 DIA 
 
 corona, and, properly speaking, a ( 
 part of the latter : so called be-' 
 cause it represents denticuli, or 
 small teeth, placed at equal inter- 
 vals apart. 
 
 Dentils, ornaments resembling teeth, 
 used in the bed-monldings of Ionic, 
 Corinthian, and Composite cornices. 
 
 Departure, in navigation, is the east- 
 ing or westing of a ship with re- 
 spect to the meridian from which 
 it departed or sailed ; or it is the 
 difference of longitude between the 
 present meridian and where the last 
 reckoning was made. 
 
 Depression of the pole, in navigation : 
 so many degrees as you sail from 
 the pole towards the equator, so 
 many you are said to depress the 
 pole, because it becomes so much 
 lower in the horizon. 
 
 Derrick, a Cornish word for a miner. 
 
 Derrick, in navigation, a tackle used 
 at the outer quarters of the mizen- 
 yard ; it also signifies a prop or 
 support to sheers, etc. 
 
 Derrick. Sheers and Gyn have one 
 object in common, to find a point 
 or fulcrum in space to which the 
 pulley, in the shape of block and 
 tackle, is to be supplied ; and this 
 is effected by the above, on one, 
 two, and three legs, respectively. 
 In the derrick and sheers, stability 
 is given by guys ; in the gyn, they 
 are unnecessary. Wherever these 
 guys are used, great attention must 
 be paid to their being well fixed, or 
 being (when requisite) duly eased- 
 otf: when accidents occur from 
 neglect in this respect, they are 
 generally very severe. 
 
 Describent, in geometry, is the line or 
 surface from the motion of which 
 a surface or body is supposed to 
 be generated or described. 
 
 Descriptive geometry : the applica- 
 tion of geometrical rules to the 
 representation of the figures and 
 the various relations of the forms 
 of bodies, in accordance to forms 
 applicable to civil, military, and 
 naval architecture, civil and me- 
 chanical engineering, and the other 
 
 148 
 
 arts that require more correct sci- 
 entific representations than have 
 hitherto been afforded to the stu- 
 dent. 
 
 Desiccation, the chemical operation of 
 drying bodies, sometimes effected 
 by drying in the air, sometimes in 
 warm chambers, by the air-pump, 
 etc. 
 
 Design, a term in the fine arts, is em- 
 ployed first to signify the art of 
 drawing or representing in lines 
 the form of any object ; next it ex- 
 presses that combination of inven- 
 tion and purpose which enables the 
 artist to compose a picture or a 
 group, without reference to the 
 material in which it is executed. 
 
 Designing, the art of delineating or 
 drawing the appearance of natural 
 objects by lines. 
 
 Destina, according to Vitruvius, a 
 column or pillar to support an edi- 
 fice. 
 
 Detrampe, in painting, in water- 
 colours. 
 
 Device, an emblem or ensign for- 
 merly borne on shields or em- 
 broidered upon banners as a cogni- 
 zance; contemporary, in the history 
 of heraldry, with coat armour it- 
 self. 
 
 Device, in heraldry, painting, etc., any 
 emblem used to represent a certain 
 family, person, action, or quality, 
 with a suitable motto, applied in a 
 figurative sense. 
 
 Diagonal, a line drawn from angle to 
 angle. 
 
 Diagonal rib, a projecting band of 
 stone or timber passing diagon- 
 ally from one angle of a vaulted 
 ceiling across the centre to the 
 opposite angle. 
 
 Diagonal scale. Equidistant parallel 
 lines cut all lines drawn across 
 them into equal parts ; conse- 
 quently a set of equidistant paral- 
 lels laid down upon a ruler, with 
 oblique lines of various lengths 
 drawn across them, give with the 
 compasses the means of imme- 
 diately taking off various propor- 
 tions of those lines. 
 
DIA 
 
 DIES. 
 
 DIE 
 
 Diagram, a delineation of geometrical 
 figures; a mathematical illustration. 
 
 Diagraphic Art, the art of painting 
 or engraving. 
 
 Dial, an instrument for the measuring 
 of time ; not mentioned in Scrip- 
 ture before the reign of Ahaz, A.M. 
 3262. It is not clearly ascertained, 
 even after this time, how the Jews 
 divided the time by hours. The 
 word hour occurs first in Tobit, 
 which may confirm the opinion 
 that the invention of dials came 
 from beyond the Euphrates. 
 
 Dialling. In all dials, the gnomon 
 represents the axis of the earth ; 
 hence its angle with the horizon is 
 the latitude of the place, and it 
 lies in the plane of the meridian. 
 There are a great variety of dials, 
 according to whether they are hori- 
 zontal, oblique, or vertical, and also 
 depending on their aspect with re- 
 ference to the sun, etc. 
 
 Diamicton, according to Pliny, a term 
 used by the Roman builders to 
 designate a particular manner of 
 constructing walls, the exterior of 
 masonry and the interior of rub- 
 ble. 
 
 Diamond, a genus of precious stones 
 of a fine pellucid substance of great 
 hardness, and never debased by 
 any admixture of earthy or other 
 coarse matter. When pure, it is 
 perfectly colourless. It is the most 
 valuable of all gems, arid is found 
 only in the East Indies and the 
 Brazils. It is constituted solely of 
 carbon in its densest, form. 
 
 Diamond, glaziers 1 , the pencil dia- 
 mond, used in cutting glass, is a 
 small fractured piece of diamond. 
 
 Diaper ornament, of flowers, applied 
 to a plain surface, either carved 
 or painted : if carved, the flowers 
 are entirely sunk into the work 
 below the general surface ; they 
 are usually square, and placed close 
 to each other, and are various in 
 their pattern and design : it was 
 first introduced in the early Eng- 
 lish style in some of the principal 
 Gothic structures in England. 
 
 149 
 
 Diaper, a panel or flat recessed sur- 
 face covered with carving or other 
 wrought work in low relief; a kind 
 of linen cloth, wrought with figures 
 in the process of weaving. 
 
 Diastyle, an arrangement of columns 
 in Grecian and Roman architecture, 
 in which the intercolumniation or 
 space between them is equal to 
 three or four diameters of the 
 shaft. 
 
 Diathyra, the vestibule before the 
 doors of a Greek house, corres- 
 ponding with the prothyra of the 
 Romans. 
 
 Diatoni, the angle stones of a wall, 
 wrought on two faces, and which, 
 stretching beyond the stones above 
 and below them, form a good band 
 or tie to the work. 
 
 Diatoni, according to Vitruvius, the 
 girders or band-stones formerly 
 employed in constructing walls ; 
 corner stones. 
 
 Diatretum, an enchased or curiously 
 engraved vase or drinking-cup. 
 
 Diaulon, a race-course, the circuit of 
 which was two stadia, or 1200 feet; 
 whence it was used to signify a 
 measure of two stadia. 
 
 Dicrotum, a boat with two oars. 
 
 Die, the cube or dado of a pedestal. 
 
 Die or Dye, a naked square cube : 
 thus the body of a pedestal, or 
 that part between its base and 
 its cap, is called the die of the pe- 
 destal. 
 
 Dies, two pieces of hardened steel, 
 which, when placed together, form ! 
 a female screw (or a screw in a j 
 nut) which has cutting edges, used j 
 for making a screw on a bolt. 
 
 Die-sinking : in the preparation of 
 coined money and of medals, the 
 most important feature is the en- 
 graving of the die which is to form 
 the stamp. The piece of steel is 
 prepared with care, and brought 
 to a soft state when about to be 
 submitted to the hands of the en- 
 graver. By the aid of small, fine, 
 hardened steel tools, the engraver 
 cuts away the steel until he has 
 produced, in cavity or intaglio, an 
 
DIE 
 
 DILAPIDATION. 
 
 DIM 
 
 exact reverse of the design for tli 
 medal or coin. 
 
 Dieu et mon droit, ' God and my 
 right,' in heraldry ; the motto of 
 the royal arms of England, first 
 assumed by Richard I. 
 
 Differential thermometer. This in- 
 strument was invented by the same 
 gentleman who contrived the pho- 
 tometer and setherioscope, and 
 was used by him in his investi- 
 gations on heat. Its principal use 
 to the meteorologist is to make 
 experiments on the light and heat 
 of the moon, etc., by concentrating 
 its rays, by a lens upon the sentient 
 ball. This can only be done when 
 the moon is on the meridian. It 
 is peculiarly adapted for measuring 
 the effect of radiation. 
 
 Digester, a boiler invented by Papin 
 for raising water to a higher tem- 
 perature than the common boiling 
 point, 212: this is effected by 
 forming a vessel somewhat resem- 
 bling a kitchen pot ; the mouth is 
 formed into a flat ring, so that a 
 cover may be screwed tightly on ; 
 this cover is furnished with a safety- 
 valve, loaded to the required pres- 
 sure. 
 
 Digit, a finger; a term employed to 
 signify any symbol of number from 
 to 9 : thus ten (10) is a number 
 of two digits. 
 
 Digit, a measure of length, containing 
 three-fourths of an inch. 
 
 Diglyph, in architecture, an imperfect 
 triglyph, with only two channels 
 instead of three. 
 
 Dilapidation, decay for want of repair ; 
 not unfrequently a point of dispute 
 between a party in possession of a 
 house and another party having an 
 interest therein. Where there is a 
 right to use lands or houses, ques- 
 tions will arise as to the manner in 
 which they ought to be used, and 
 by whom dilapidations, whether 
 caused by accident or decay, ought 
 to be supplied. The rights of par- 
 ties with respect to immovable 
 property so closely border on each 
 other, and the line of demarcation 
 
 150 
 
 between them is so indistinct, that 
 one man, in the fancied exercise of 
 his right, is continually liable to 
 encroach upon or disregard the 
 right of another. No person, how- 
 ever absolute his property in land, 
 can put it to any use he pleases : 
 his right to use it is restrained by 
 the rights of his neighbour ; he is 
 bound to take care that his manner 
 of using does not interfere with 
 the inoffensive and profitable occu- 
 pation by his neighbour of his land. 
 (See the second edition, just pub- 
 lished, of Mr. Gibbons's elaborate 
 work on the ' Law of Dilapidations 
 and Nuisances.') 
 
 Dilettante (Italian), an ardent admirer 
 of the fine arts. The Dilettanti 
 Society, consisting of many dis- 
 tinguished noblemen and gentle- 
 men, has done much to rescue the 
 noble monuments of Grecian art 
 from otherwise inevitable ruin. 
 
 Dilleuing, a Cornish word for a method 
 of washing or finishing the dress- 
 ing of tin in very fine hair sieves. 
 
 Diluvial formation, the superficial 
 deposits of gravel, clay, sand, etc., 
 which lie far from their original 
 sites on hills, and in other situ- 
 ations, to which no forces of water 
 now in action could transport them. 
 
 Dilving, in dressing tin ore, shaking 
 it in a canvas sieve, in a tub of 
 water, so that the waste flows over 
 the rim of the sieve, leaving the 
 tin behind. 
 
 Dimension, a term used in the same 
 sense as degree. 
 
 Dimensions. 1. General dimensions: 
 size, magnitude, dimension, bulk, 
 volume, largeness, massiveness. 2. 
 Linear dimensions. 3. Central. 
 
 Diminution, a term expressing the 
 gradual decrease of thickness in 
 the upper part of a column. 
 
 Diminution of columns. The shafts 
 of columns are diminished in dia- 
 meter as they rise, sometimes from 
 the foot itself of the shaft, some- 
 times from one-quarter, and some- 
 times from one-third of its height. 
 The diminution at top is seldom 
 
DIG 
 
 DIVING-BELL. 
 
 DIV 
 
 less than one-eighth or more than 
 one-sixth of the inferior diameter 
 of the column. 
 
 Dioptase or emerald copper, a crys- 
 talized silicate of copper, the pri- 
 mary form of which is a rhomboid. 
 Its colour varies from emerald to 
 blackish green : it is translucent 
 and brittle. 
 
 Dioptra, a geometrical instrument 
 employed in measuring the altitude 
 of distant objects, and for taking the 
 levels of a source of water intended 
 to be conveyed to a distance by 
 means of an aqueduct. 
 
 Diorama, a mode of scenic exhibi- 
 tion invented by two French artists, 
 Daguerre and Bouton. 
 
 Dip, in mining, the greatest inclina- 
 tion of a stratum to the hori- 
 zon. 
 
 Di Palito is a light yellow ochre, 
 affording tints rather purer in co- 
 lour than the stone ochre, but less 
 so than Naples yellow. Many 
 pleasing varieties of ochreous co- 
 lours are produced by burning 
 and compounding with lighter, 
 brighter, and darker colours, but 
 often very injudiciously and ad- 
 versely to that simple economy of 
 the palette which is favourable to 
 the certainty of operation, effect, 
 and durability. 
 
 Diphryges, the scorial sediment, a 
 calx of melted copper, gathered in 
 the furnace when the metal was 
 run out. 
 
 Diplinthius, according to Vitruvius, 
 two bricks thick. 
 
 Dipping-needle, in navigation, a mag- 
 netic needle, so hung that one end 
 dips, or inclines to the horizon, and 
 the other is proportionally elevated, 
 forming an angle equal to the dip- 
 ping of the needle at the place 
 where the experiment is made. 
 
 Dipping (among miners), the inter- 
 ruption or breaking off of the vein 
 of ore. 
 
 Dipteral, having a double range of 
 columns all round ; a dipteral tem- 
 ple usually had eight in the front 
 row of the end porticoes, and fifteen 
 
 151 
 
 at the sides, the columns at the 
 angles being included in both. 
 
 Dipteron, in ancient architecture, a 
 temple surrounded with a double 
 row of columns which form porti- 
 coes, called wings or aisles. 
 
 Dipteros, in Greek architecture, a 
 temple with a double row of co- 
 lumns on each of the four sides. 
 
 Direct-action engine, an engine having 
 the rotatory motion communicated 
 to a crank placed directly over the 
 cylinder, so as to save height, and 
 lessen the weight of the engine : 
 the term applies more particularly 
 to marine engines. 
 
 Discharging arch, an arch formed in 
 the substance of a wall, to relieve 
 the part which is below it from the 
 superincumbent weight : it is fre- 
 quently used over lintels and flat- 
 headed openings. 
 
 Discord, a term applied to painting 
 when there is a disagreement of 
 the parts or the colouring ; when 
 the objects appear foreign to each 
 other, and have an unpleasing and 
 unnatural effect. 
 
 Disembogue, to pour out at the mouth 
 of a river. 
 
 Distemper, in painting, the working- 
 up of colours with something else 
 besides mere water or oil. If the 
 colours be prepared with the first, 
 it is called limning ; and with the 
 last, painting in oil. 
 
 Distemper is a preparation of 
 colours without oil, only mixed 
 with size, whites of eggs, or any 
 such proper glutinous or unctuous 
 substance : with this kind of colour 
 all the ancient pictures, before the 
 year 1410, were painted, as also are 
 the celebrated cartoons of Raphael. 
 
 Disti Salvi built the Baptisteryof Pisa. 
 
 Ditriglyph, an interval between two 
 columns, admitting two triglyphs 
 in the entablature ; used in the 
 Doric order. 
 
 Dividiculum, in Rome, a tower on an 
 aqueduct, containing a large reser- 
 voir. 
 
 Diving-bell, a machine contrived for 
 safely lowering a man to any rea- 
 
DIV 
 
 DOCKS. 
 
 DOC 
 
 sonable depth under water, so that 
 he may remain there for a consi-* 
 derable time. 
 
 Division of an Order. The general 
 division of an Order being into two 
 parts, namely, the column and en- 
 tablature, the column is subdivided 
 into three unequal parts, viz. the 
 base, the shaft, and the capital. 
 The entablature consists also of 
 three unequal parts, which are, the 
 architrave, the frieze, and the cor- 
 nice. Each of these divisions con- 
 sists of several smaller parts, which 
 by their variety and peculiarity dis- 
 tinguish the Orders from each other. 
 
 Dock, a place artificially formed for 
 the reception of ships, the entrance 
 of which is generally closed by 
 gates. There are two kinds of 
 docks, dry docks and wet docks : 
 the former are used for receiving 
 ships for repair, the latter for the 
 purpose of keeping vessels afloat. 
 
 Docks are enclosed artificial re- 
 ceptacles for shipping, and are 
 usually formed by excavation of the 
 soil and constructed walls of ma- 
 sonry, with inlets and gates for ad- 
 mittingthepassageof vessels. Docks 
 are usually distinguished as wet 
 docks or basins and dry or graving 
 docks. The former of these are 
 already described under the head 
 Basin ; the latter may be described 
 as follows : 
 
 Graving docks, in which repairs 
 of vessels are effected, are con- 
 structed of various dimensions, ac- 
 cording to the class of vessel for 
 which provision is intended. Se- 
 veral splendid works of this kind 
 have, within the last few years, 
 been executed in the English dock- 
 yards. One of these the Eastern 
 Dock in Her Majesty's Dockyard 
 at Woolwich is 282 feet in ex- 
 treme length, 81 feet in width on 
 the ground level, and 39 feet in 
 the bed. The depth from the 
 ground level to the bed is 27 feet. 
 The inclined sides and curved end 
 of the masonry are formed into a 
 series of steps or altars, by which 
 
 152 
 
 access is readily obtained to all 
 parts of the dock, and fixing-places 
 obtained for the struts with which 
 the sides of the vessel under repair 
 are maintained in an upright posi- 
 tion, when the water is discharged 
 from the dock. The river-wall of 
 this structure was originally con- 
 structed of concrete block-facings 
 with rough concrete backings, ac- 
 cording to a plan introduced i.ito 
 this country by Mr. Ranger ; but 
 these were abandoned, and granite 
 facings substituted, the entire mass 
 of the wall being supported on 
 timber-piling. The whole of the 
 piers, apron, and coffer-dam walls 
 were executed by tide-work, in the 
 following manner: a small space 
 was surrounded by sheet-piling, 
 which was carried up from 6 to 8 
 feet above the level of low-water : 
 into the enclosure thus formed a 
 pipe from two 18-inch pumps, 
 worked by a steam-engine, was 
 led, and the pumps set to work as 
 soon as the tide fell below the 
 sheet-piling. The subsequent ex- 
 cavation for the dock reached a 
 bed of chalk, which was found to 
 be sufficiently firm to dispense with 
 the inverted arch of masonry usu- 
 ally constructed beneath the bed of 
 these docks, and the floor was con- 
 sequently constructed of a hori- 
 zontal paving of blocks of granite 
 
 2 feet in thickness, each stone, 
 being joggled to the adjacent stones 
 with dove-tail joggles of Valentia 
 slate bedded in cement. The river 
 water is admitted into the dock 
 through a culvert 5 feet high and 
 
 3 feet wide, passing through each 
 pier, and which culverts are worked 
 by sluices of cast-iron. The front 
 of the dock is closed with a caisson 
 formed of plate-iron, fixed with 
 rivets to ribs of angle-iron ; the 
 form of the caisson being similar 
 to that of a vessel, namely, with a 
 continuous keel along the bottom 
 and up each end, and a swelling 
 outline tapering towards the end 
 keels, and reduced to a width nearly 
 
DOC 
 
 DOCKS. 
 
 DOC 
 
 parallel in the dock-level. This 
 continuous keel, which is of oak, 
 and formed in two pieces, fits into 
 a recess in the masonry at the en- 
 trance of the dock, and the admis- 
 sion of water into it is regulated 
 by sluices and pumps. 
 
 From the description given of 
 graving docks, it will be under- 
 stood that their action and efficiency 
 depend upon the command of an 
 adequate depth of water, and a 
 sufficient rise and fall of tide to 
 leave the vessel dry or to float her, 
 as occasion requires. The use of 
 these docks also compels the re- 
 tention of the vessel during the 
 action of the tide, and thus in- 
 volves a considerable lapse of time, 
 which sometimes cannot be af- 
 forded for trifling repairs or ex- 
 amination of a vessel in active ser- 
 vice. 
 
 For situations in which no tide 
 exists, a different arrangement be- 
 comes necessary, and a construction 
 called a ' slip ' is commonly substi- 
 tuted for a graving dock. The 
 slip which has been the most ex- 
 tensively used is that known as 
 ' Morton's slip,' and which was 
 secured by a patent dated March 
 23, 1819, granted to T. Morton, 
 for a method of dragging ships out 
 of water for repairs, etc. This 
 slip consists of an inclined plane, 
 formed of timber framing laid upon 
 suitable foundations of masonry, 
 or cut in the surface of the rock. 
 Upon this framing longitudinal 
 metal racks are fixed, and a move- 
 able carriage, upon which the ves- 
 sel is received (by running the 
 carriage to the lower part of the 
 plane, beneath the water, and se- 
 curing the vessel upon it), is fitted 
 with cog-wheels, or other suitable 
 apparatus for working upon these 
 racks. The moving carriage con- 
 sists of a succession of small strong 
 blocks or carriages, any number of 
 which may be connected together, 
 according to the length of vessel 
 to be hauled up. Each of these 
 
 blocks or carriages, which are laid 
 in corresponding pairs on each 
 side of the central line of the slip, 
 so as to leave a continuous inter- 
 mediate space to receive the keel 
 of the vessel, is fitted with rollers, 
 upon which it may be moved trans- 
 versely ; and thus the distance be- 
 tween the two blocks of each pair, 
 or on each side of the centre, may 
 be adjusted according to the sec- 
 tional form of the ship. These 
 motions are ingeniously effected 
 with the aid of cross-ropes or lines 
 which are fixed to the blocks, and 
 by which means the entire action 
 of the apparatus is much facili- 
 tated. The combined carriage, 
 when loaded with the vessel, is 
 hauled up the slip by cables at- 
 tached to a drum apparatus, with 
 suitable gearing fixed in a building 
 at the head or upper end of the 
 slip. The power required is of 
 course in proportion to the weight 
 to be hauled up, and to the rate of 
 inclination of the slip, and is usu- 
 ally supplied by a steam-engine. 
 
 This principle is susceptible of 
 being extended, so as to provide 
 berths for several vessels with only 
 one hauling-up slip and machinery. 
 For this purpose it has been sug- 
 gested to construct a series of 
 frames arranged radially round a 
 centre, and capable of motion and 
 of adjustment, with one slip con- 
 structed in such a direction as to 
 correspond with a produced radius 
 of the same circle. This arrange- 
 ment, which would be similar to 
 that of the polygonal engine-houses 
 now erected on several lines of 
 railway, offers great facilities for 
 extended operations in the repair 
 of vessels, but of course requires 
 great space for the construction of 
 the radial frames. 
 
 In order to provide for cases in 
 which sufficient tidal difference 
 cannot be had for raising vessels of 
 deep draughts on to a dry dock, 
 floating docks have been introduced 
 in North America, and found to 
 
DOC 
 
 DOGS. 
 
 DOG 
 
 act satisfactorily. These floating^ 
 docks are constructed with a buoy- 
 ant bed or cradle, capable of sup- 
 porting a vessel within the dock, 
 with its keel above the surface of 
 the water. This float or cradle is 
 made in a box-like form, composed 
 of strong logs, jointed firmly, and 
 well caulked, so as to make it 
 water-proof. The capacity of the 
 float must be such that when freed 
 from water by pumping, and loaded 
 with the vessel, workmen, etc., it 
 shall sustain the load with safety. 
 The float moves within a recess 
 of masonry, by which its motion 
 is guided and secured. Suitable 
 shores, blocks, struts, etc., are used 
 in making the vessel steady within 
 the float, which is fitted with valves 
 in the lower part. The action of 
 this floating dock is as follows : 
 The cradle or float, being full of 
 water (the valves being open), is 
 sunk so that the vessel may be 
 brought over it, and temporarily 
 secured in position : the valves are 
 then closed, and the pumps set to 
 work to clear the water from the 
 float, which rises in consequence, 
 and brings up the vessel to a dry 
 level. When the ship is again ready 
 for sea, the opening of the valves 
 admits the water, and sinks the 
 float, leaving the vessel free above 
 it to pass out of the dock. 
 
 The docks and basins of London 
 and Liverpool comprise some of 
 the largest specimens of works of 
 this kind. Those of the latter port 
 were commenced in 1708, and con- 
 sist of several docks of great ex- 
 tent. The first public docks for 
 merchant shipping in London were 
 the West India Docks, opened in 
 1805, the great basin of which is 
 420 yards in length, and 230 yards 
 in width. This is connected with 
 the river by another basin of about 
 three acres in area. The London 
 Docks were commenced soon after 
 the West India Docks, and opened 
 in the same year, viz. 1805. The 
 principal basin of these docks is 
 
 154 
 
 420 yards in length, and 276 yards 
 in width. The East India Dock 
 for unloading inwards is 470 yards 
 in length, and 173 yards in width ; 
 and that for loading outwards is 
 260 yards in length, and 140 yards 
 in width. The St. Katharine's 
 Docks occupy an area of 24 acres. 
 
 Dodecagon, in geometry, a figure of 
 twelve angles and sides. 
 
 Dodecahedron, in geometry, one of 
 the regular bodies comprehended 
 under twelve equal sides, each of 
 which is a pentagon. 
 
 Dodecastyle, a building having twelve 
 columns in front. 
 
 Dogs, or andirons, creepers, braziers, 
 etc. Long after the general intro- 
 duction of chimneys, wood was the 
 ordinary fuel for all sorts of apart- 
 ments. Coals formed no part of 
 the ' liveries,' but wood was com- 
 monly included in them. A ' cra- 
 dle for sea-coal' is however fre- 
 quently mentioned as belonging to 
 the chief rooms in superior houses, 
 though the usual way of warming, 
 or rather airing, bed-chambers was 
 with braziers or chafing dishes. 
 Andirons are a larger and higher 
 sort of irons, made to support the 
 wood, and have usually long necks 
 rising up before, to prevent the 
 wood from falling upon the floor. 
 Creepers are smaller and lower 
 irons with short necks, or none at 
 all, which are placed between the 
 andirons, to keep the ends of the 
 wood andthebrandsfrom the hearth, 
 that the fire may burn more freely. 
 
 Dog-kennel, a lodgement for dogs kept 
 for the purpose of field sports : 
 it is almost as invariable an ap- 
 pendage to the manor-house as 
 it was formerly to the baronial 
 castle. Bishop Percy observes, 
 " that a nobleman in the dark 
 ages, retired within his castle, had 
 neither books, nor newspapers, nor 
 literary correspondence, nor visits, 
 nor cards, to fill up his leisure : his 
 only amusements were field sports; 
 nor did the love for these decline 
 in the Tudor period." 
 
DOG 
 
 DOMES. 
 
 DOM 
 
 Dog-wood, a small underwood, free 
 from silex : small splinters are used 
 by watch-makers for cleaning out 
 the pivot-holes of watches ; it is 
 also used by butchers for making 
 skewers. 
 
 Dogger, a ship of about eighty tons 
 burden, with a well in the middle, 
 to bring fish alive to shore. 
 
 Dolomite, massive magnesian lime- 
 stone, used by the ancient sculptors 
 in their best works. 
 
 Dolphin, a technical term applied to 
 the pipe and cover at a source for 
 the supply of water. 
 
 Dome, a term applied to a covering of 
 the whole or part of a building: 
 the word dome is strictly applied 
 to the external part of the spheri- 
 cal or polygonal roof, and cupola 
 to the internal part. 
 
 Dome or cupola, a roof, the base of 
 which is a circle, an ellipsis, or a 
 polygon, and its vertical section a 
 curve line, concave towards the in- 
 terior. Hence domes are called 
 circular, elliptical, or polygonal, 
 according to the figure of the base. 
 The most usual form for a dome 
 is the spherical, in which case its 
 plan is a circle, the section a seg- 
 ment of a circle. The top of a 
 large dome is often finished with a 
 lantcrii, which is supported by the 
 framing of the dome. The interior 
 and exterior forms of a dome are 
 not often alike, and in the space 
 between, a staircase to the lantern 
 is generally made. According to 
 the space left between the external 
 and internal domes, the framing 
 must be designed. Sometimes the 
 framing may be trussed with ties 
 across the opening; but often the 
 interior dome rises so high that 
 ties cannot be inserted. Accord- 
 ingly, the construction of domes 
 may be divided into two cases : 
 viz. domes with horizontal ties, 
 and those not having such ties. 
 
 Dome, in locomotive-engines, the 
 conical part of the boiler, forming 
 a steam-chamber, and terminating 
 the top of the fire-box part. In 
 
 155 
 
 a locomotive-engine the safety- 
 valves are usually placed on the 
 top of the dome or the body of the 
 boiler. 
 
 Dome-cover, in locomotive-engines, 
 the brass or copper cover which 
 encloses the dome, to prevent the 
 radiation of heat. 
 
 Dome Cathedral of Pisa, the first 
 model of that Tuscan style of ar- 
 chitecture, so solid, grave, and im- 
 posing, neither Greek nor Gothic, 
 was begun in the eleventh century; 
 and in the thirteenth was founded 
 the majestic church of Santa Maria 
 dei Fiori at Florence, of which the 
 dome equals in size that of St. 
 Peter's at Rome, and was its 
 model. 
 
 Dome of St. Paul's Cathedral (the) is 
 elliptical, and built of wood; it is 
 confined by strong chains, consist- 
 ing of iron bars : that of the Pan- 
 theon at Rome is nearly circular, 
 and its lower parts are so much 
 thicker than its upper parts as to 
 afford sufficient resistance to their 
 pressure ; they are supported by 
 walls of great thickness, and fur- 
 nished with many projections which 
 answer the purpose of abutments 
 and buttresses. 
 
 Domes in Asia are probably more 
 ancient than in Italy. At Lanker- 
 rood, at Dhay-nain, at Sin-sin, five 
 or six days' journey south of Tehe- 
 ran, in Persia, the towns are all de- 
 serted : there are about a hundred 
 large dwelling-houses quite entire, 
 of a very singular construction. 
 Each edifice stands separate, and 
 is constructed of several central 
 arches supporting a pointed dome; 
 while smaller divisions project from 
 the body of the building, also 
 arched, and the whole finished 
 with the greatest neatness, having 
 remains of stucco-painted walls 
 within. 
 
 It is probable that the arch and 
 vault and dome were not unknown 
 to the nations in the East, beyond 
 the Indies, in a very remote age ; 
 but in Greece and in Asia Minor 
 
DOM 
 
 DOMESTIC BUILDINGS AND CASTLES. 
 
 DOM 
 
 there are no traces of them before 9 
 their introduction by the Romans. 
 To the Romans they were familiar 
 at a very early period of their his- 
 tory ; a knowledge of which they 
 borrowed perhaps from the Etrus- 
 cans, or from the supposed extinct 
 people who possessed a city on 
 the site of Rome itself, before the 
 Romans. 
 
 Domestic Architecture in England. 
 At the termination of the York and 
 Lancaster wars, the fortified style 
 of architecture was gradually aban- 
 doned in England ; and as we had 
 no other model of domestic archi- 
 tecture than the gable and the cot- 
 tage, by the duplication of this 
 simple form, in various positions, 
 was constructed what has been 
 called the Old English Manor- 
 house style. If we take a common 
 two-floored English gable and cot- 
 tage, add to it one, two, or three 
 cottages side by side, of the same 
 size, and, in order to gain rooms 
 out of the roof on the sides of this 
 double or triple cottage, raise gable 
 ends either projecting from the 
 ground to the top of the roof, or 
 merely raised from the eaves-drop; 
 if we insert broad low windows, 
 divided by simple wooden or stone 
 mullions, in these projecting gable 
 ends, and similar windows at the 
 ends of this double or triple cot- 
 tage ; ornament the inclined sides 
 of the gable ends above the eaves- 
 drop by steps or small pinnacles, or 
 both ; then add a parapet, plain or 
 embattled, we have a manor-house 
 in the most florid style. Many 
 such houses came afterwards to be 
 adorned by a centre of architec- 
 tural decoration, in which Roman, 
 Grecian, and Gothic were strangely 
 mixed. There is, however, a cer- 
 tain degree of antique-like gran- 
 deur in such houses, which pro- 
 duces a very striking impression. 
 This step towards a better style 
 took place before the time of Inigo 
 Jones. 
 
 "The mansion at South Elmham, 
 
 156 
 
 when entire, formed a quadrangle, 
 as usual, of which stables and 
 offices made up a part. The do- 
 mestic and ecclesiastical styles are 
 singularly combined in this build- 
 ing, though the latter seems to 
 predominate; and the occasional 
 discovery of old floor-stones, of a 
 sepulchral character, intimates that 
 the projecting porch led to the 
 chapel of the dwelling, not into 
 the hall ; and yet the ceilings of 
 the chambers where the two wings 
 and upper windows are observed, 
 on the right hand of the porch, are 
 flat, divided into small squares by 
 the girders above, and covered with 
 plastered mouldings, in the manner 
 usually seen in dwellings of an early 
 period." 
 
 Domestic buildings and castles. The 
 towns and ordinary houses of the 
 Normans were entirely built of 
 wood, and, for the most part, are 
 so to this day. Their castles, 
 having but one destination, that 
 of defence, aimed at nothing but 
 strength in their plan or con- 
 struction. A site was also selected 
 which was already fortified by 
 nature. 
 
 The plan of the Norman castles 
 was as nearly the same as the di- 
 versity of ground would allow. 
 The principal feature was always 
 the keep, which contained the 
 apartments of the lord of the cas- 
 tle, and was also meant to be the 
 last refuge of the garrison, if the 
 outer works were forced. The keep 
 was usually raised on an artificial 
 mound, or placed on the edge of a 
 precipice. The walls, strengthened 
 in every way that art could devise, 
 were of immense thickness, and 
 composed of grouting poured in 
 between two solid walls of stone. 
 The facing consisted sometimes of 
 irregular courses, and sometimes of 
 small squared stones, after the Ro- 
 man manner. Ashler was usually 
 introduced at the angles of the 
 building. The windows were few, 
 and little more than chinks, unless 
 
DOM 
 
 DOORS. 
 
 DOO 
 
 very high up, or turned to the 
 court. The door of entrance could 
 only be reached by a staircase. 
 Under the keep were usually 
 vaults, or dungeons, for the recep- 
 tion of prisoners. The keep was 
 enclosed in two courts surrounded 
 by walls flanked with towers. The 
 tower at the entrance was called 
 the barbican, and served at once 
 for an outwork and post of obser- 
 vation. The whole fortress was 
 defended by a moat. 
 
 The remains of the Norman cas- 
 tles which exist scarcely afford any 
 specimens of early Norman con- 
 struction, almost all these castles 
 having been besieged, destroyed, 
 and rebuilt, over and over again. 
 The keep of Falaise is perhaps the 
 only castellated remnant of early 
 Norman times. The castle of Gi- 
 zors, which was built by William 
 Rufus, retains nothing of its origi- 
 nal construction. 
 Doorway (Anglo- 
 Norman). The 
 Anglo - Norman 
 builders bestowed 
 much pains and 
 evinced consider- 
 able artistic skill 
 in very elaborately 
 ornamenting the 
 portal entrances 
 to churches in 
 their style of ar- 
 chitecture, by a 
 profusion of orna- 
 mental mouldings 
 and of sculpture. 
 Very many ex- 
 amples are to be 
 met with in great 
 variety in several 
 of the counties of 
 England, particu- 
 larly in the coun- 
 ties of Norfolk 
 and Suffolk. The 
 example repre- 
 sented in the an- 
 nexed engraving 
 is a beautiful spe- 
 
 157 
 
 cimen taken from the church of St. 
 Botolph, at Cove, in the county 
 of Suffolk. 
 
 Domus, a private house occupied by 
 a single proprietor and his family. 
 
 Doors (Antique). The Greeks in the 
 temple of Minerva Polias, at 
 Athens, and also the Romans in 
 the temple of Vesta, or the Sibyl, 
 at Tivoli, made the doors and win- 
 dows smaller at top than at bot- 
 tom : the architrave or dressing 
 always constituted an agreeable 
 decoration when in character with 
 the building. Those of the win- 
 dows in the Grecian temple have 
 a projection, or what is sometimes 
 termed a knee, at their upper angle; 
 while those of the temple of Vesta, 
 whose apertures have the same 
 form, continue without interrup- 
 tion, and are surmounted by a cor- 
 nice ; but the cornice above the 
 door is separated from the archi- 
 
DOO 
 
 DORIC ORDER. 
 
 DOR 
 
 trave by a frieze, while the cornice, 
 of the windows joins the archi- 
 trave. In the temple of Minerva, 
 the architrave of the windows rests 
 only on a plain socle ; those of the 
 temple of Vesta rest also on a socle 
 or support, the face of which is sunk. 
 
 Doors (Modern). There are two 
 doors, designs of Vignola, which 
 offer in their profiles and propor- 
 tions a happy medium between the 
 antique and modern compositions; 
 and all other designs of this kind 
 are either derived from them, or pos- 
 sess a vague character which ren- 
 ders them unworthy of imitation. 
 
 There are breaks in the archi- 
 trave, as in those of the temple 
 of Minerva Polias ; and the ter- 
 mination or lower extremity of 
 these breaks determines the length 
 of the consoles, which gives har- 
 mony to the arrangement. These 
 consoles are also placed against a 
 second architrave, beyond which 
 the first projects. The design of 
 the door of the church of St. Lo- 
 renzo is more regular. 
 
 Doorways. In the Gothic, and the 
 architecture of the middle ages, 
 doorways are striking and impor- 
 tant features, affording in the cha- 
 racter of the mouldings and orna- 
 ments the style and period of the 
 edifice. 
 
 Doric Order. The Doric order, says 
 Palladio, was invented by the Do- 
 rians and named from them, being 
 a Grecian people which dwelt in 
 Asia. If Doric columns are made 
 alone without pilasters, they ought 
 to be seven and a half or eight 
 diameters high. The intercolumns 
 are to be little less than three 
 diameters of the columns ; and this 
 manner of spacing the columns is 
 by Vitruvius called Diastylos. 
 
 The ancients employed the Doric 
 in temples dedicated to Minerva, 
 to Mars, and to Hercules, whose 
 grave and manly dispositions suited 
 well with the character of this 
 order. Serlio says it is proper for 
 churches dedicated to Jesus Christ, 
 
 158 
 
 to St. Paul, St. Peter, or any other 
 saints remarkable for their forti- 
 tude in exposing their lives and 
 suffering for the Christian faith. 
 Le Clerc recommends the use of 
 it in all kinds of military build- 
 ings ; as arsenals, gates of fortified 
 places, guard-rooms, and similar 
 structures. It may likewise be 
 employed in the houses of generals 
 or other martial men, in mauso- 
 leums erected to their memory, or 
 in triumphal bridges and arches 
 built to celebrate their victories. 
 
 Vitruvius himself makes the Do- 
 ric column in porticoes higher by 
 half a diameter than in temples ; 
 and most modern architects have, 
 on some occasions, followed his 
 example. In private houses, there- 
 fore, it may be 16, 16, or 16-| 
 modules high ; in interior decora- 
 tions, even seventeen modules, and 
 sometimes perhaps a trifle more ; 
 which increase in the height may be 
 added entirely to the shaft, as in 
 the Tuscan order, without changing 
 either the base or capital. The 
 entablature, too, may remain un- 
 altered in all the aforesaid cases ; 
 for it will be sufficiently bold with- 
 out alteration. 
 
 The height of the Doric column, 
 including its capital and base, is 
 sixteen modules ; and the height 
 of the entablature, four modules ; 
 the latter of which being divided 
 into eight parts, two of them are 
 given to the architrave, three to 
 the frieze, and the remaining three 
 to the cornice. 
 
 In most of the antiques, the 
 Doric column is executed without 
 a base. Vitruvius likewise makes 
 it without one ; the base, accord- 
 ing to that author, having been 
 first employed in the Ionic order, 
 to imitate the sandal or covering 
 of a woman's foot. Scamozzi 
 blames this practice ; and most of 
 the moderns have been of his opi- 
 nion, the greatest part of them 
 having employed the Attic base in 
 this order. 
 
DOR 
 
 DOVE-TAIL. 
 
 DRA 
 
 Dorman tree, a large beam lying 
 across a room ; a joist, or sleeper. 
 
 Dormer window, a window pierced 
 through a sloping roof, and placed 
 in a small gahle which rises on the 
 side of the roof. 
 
 Dormitory, a sleeping apartment ; a 
 term formerly applied to the sleep- 
 ing-room of the inmates of monas- 
 teries and other religious houses. 
 
 Dormond, a large beam lying across 
 a room ; a joist, or sleeper : same 
 as Dorman. 
 
 Doron, a hand-breadth, or palm : 
 among the Greeks, their bricks or 
 tiles were termed tetradoron, four 
 hands' breadth, or pentadoron, five 
 hands broad; the word also im- 
 plies a gift : hence, probably, the 
 origin of the English word dowry. 
 
 Dorture, a place to sleep in, a bed- 
 chamber. " He led us to a gallery 
 
 f like a dorture." 
 
 Dosel, hangings round the walls of a 
 hall, or at the east end, and some- 
 times the sides, of the chancel of 
 a church, made of tapestry or car- 
 pet-work ; used also in churches, 
 and frequently richly embroidered 
 with silks, and gold and silver. 
 
 Dosel, ornamental and rich stuff for 
 the back of a chair, a throne, or a 
 screen of ornamental woodwork. 
 
 Double-acting pump, a pump which 
 lifts and forces water at the same 
 time, by means of a solid piston, 
 and an entrance and exit-valve 
 communicating with each side. 
 
 Double-beat valve, a valve used in 
 Cornish engines and water- works. 
 It has two beats, or seatings, one 
 above the other ; the bottom one 
 is similar to an ordinary circular 
 valve seating ; the top one is some- 
 what less in diameter than the 
 bottom one, and is supported from 
 it by ribs, and forms a cover nearly 
 the size of the inner passage. A 
 shell with two beats to correspond 
 with the seatings shuts the sides ; 
 when raised (which requires but 
 little power, as the fixed cover 
 before mentioned bears nearly all 
 the pressure, its diameter being 
 
 159 
 
 nearly equal to that of the shell) 
 the steam or water escapes at the 
 sides both of the top and bottom 
 beat. 
 
 Double-cylinder engine, a marine en- 
 gine with two cylinders placed at 
 right angles to the crank-shaft, and 
 at a small distance apart, to give 
 space for the vibration of the rod 
 connecting the crank to the long 
 end of a shaped cross-head, which 
 slides in grooves between the cy- 
 linders ; the upper ends of the 
 cross-head are connected to the 
 piston-rods. This form of engine 
 is patented by Messrs. Maudslay. 
 
 Doucine, a moulding, concave above 
 and convex below. 
 
 Dove-tail, in carpentry, a method of 
 joining two boards together by 
 letting one piece into another in 
 the form of the tail of a dove, when 
 that which is inserted has the ap- 
 pearance of a wedge reversed. 
 
 Dove-tailing, a method of fastening 
 together two pieces of metal or 
 wood by projecting bits cut in the 
 form of dove-tails in one piece, to 
 fit into corresponding hollows in 
 the other. 
 
 Dowel. A round dowel or coak is 
 the piece of timber to which the 
 felloes of a carriage-wheel are 
 united. 
 
 Dowsing cheeks, in ship-building, 
 pieces fayed across the apron, and 
 lapped on the knightheads or in- 
 side stuff above the upper deck. 
 
 Drabler, a small topsail. 
 
 Drabs,\n salt-works, a kind of wooden 
 box for holding the salt when 
 taken out of the boiling pan. 
 
 Draft-engine, an engine used for 
 pumping. 
 
 Drag -bar, a strong iron rod with 
 eye-holes at each end, connecting 
 a locomotive engine and tender by 
 means of the drag-bolt and spring. 
 
 Drag-bolt, the strong bolt coupling 
 the drag-bar of a locomotive engine 
 and tender together, and remov- 
 able at pleasure. 
 
 Drag-hook and chain, the strong chain 
 and hook attached to the front of 
 
DRA 
 
 DRAINAGE. 
 
 DRA 
 
 the engine buffer-bar, to connect, 
 it on to any other locomotive en- 
 gine or tender ; also attached to 
 the drag-bars of goods-waggons. 
 
 Drag-link, a link for connecting the 
 cranks of two shafts ; it is used in 
 marine engines for connecting the 
 crank on the main-shaft to that on 
 the inner paddle-shaft. 
 
 Drag-spring, a strong spring placed j 
 near the back of the tender. It is j 
 attached by the ends to the drag- j 
 bar which connects the engine and j 
 tender, and by the centre to the 
 drag-bar which connects the train 
 to the tender. 
 
 Dragon-beams are two strong braces 
 which stand under a breast-sum- 
 mer and meet in an angle on the 
 shoulders of the king-piece. 
 
 Dragon's blood (colour), a resinous 
 substance brought from the East 
 Indies. It is of a warm semi-trans- 
 parent, rather dull -red colour, 
 which is deepened by impure air, 
 and darkened by light. There are 
 two or three sorts, but that in drops 
 is the best. White lead soon de- 
 stroys it, and it dries with extreme 
 difficulty in oil. It is sometimes 
 used to colour varnishes and lac- 
 quers, being soluble in oils and 
 alcohol ; but notwithstanding it has 
 been recommended as a pigment, it 
 does not merit the attention of the 
 artist. 
 
 Drainage of marshes and fen lands. 
 The steam-engine is used to raise 
 the water above the level of those 
 lands which lie too low to be drained 
 by natural outfall, and also in situ- 
 ations where the fall is not sufficient 
 to carry off the superfluous water 
 in time to prevent damage to the 
 crops. 
 
 Mr. Glynn has applied steam- 
 power to the drainage of land in 
 fifteen districts, all in England, 
 chiefly in Cambridgeshire, Lincoln- 
 shire, and Norfolk. The quantity 
 of land so drained amounts to more 
 than 125,000 acres, the engines em- 
 ployed being seventeen in number, 
 and their aggregate power 870 
 
 160 
 
 horses : the size of the engines 
 varies from 20 to 80 horses. Mr. 
 Glynn was also engaged in draining 
 by steam power the Hammerbrook 
 district, close by the city of Ham- 
 burgh ; and in another level near 
 to Rotterdam, an engine and ma- 
 chinery with the requisite buildings 
 have been erected from his plans 
 by the Chevalier Conrad, and the 
 works successfully carried into 
 effect. 
 
 In British Guiana the steam-en- 
 gine has been made to answer the 
 double purpose of drainage and irri- 
 gation. Some of the sugar-planta- 
 tions of Demerara are drained of 
 the superfluous water during the 
 rainy season, and watered during 
 the dry season. 
 
 In many of the swampy levels of 
 Lincolnshire and Cambridgeshire, 
 much had been done to carry off the 
 water by natural means, and many 
 large cuts had been made and em- 
 bankments formed, especially in 
 the Bedford Level, which a'lone 
 contains about 300,000 acres of 
 fen-land ; the Great Level of the 
 fens contains about 680,000, for- 
 merly of little value, but now rich 
 in corn and cattle. The general 
 plan is to carry away the water 
 coming off the higher grounds, and 
 prevent it, as much as possible, 
 from running down into the marsh 
 by means of the catchwater drains, 
 leaving the rain alone which falls 
 upon the district to be dealt with 
 by mechanical power. As the 
 quantity of rain falling on the Great 
 Level of the fens seldom exceeds 
 26 inches in the year, and about 
 two-thirds of this quantity is carried 
 off by evaporation and absorption, 
 or the growth of plants, it is only 
 in extreme cases that 2 inches in 
 depth require to be thrown off by 
 the engines in any one month, 
 which amounts to 1 cubic foot of 
 water upon every square yard of 
 land, or 7260 feet to the acre. 
 
 The standard and accepted mea- 
 sure of a horse's power is 33,000fos. 
 
DRA 
 
 DRAINAGE. 
 
 DRA 
 
 raised 1 foot high in a minute, or 
 3300fts. raised 10 feet high in the 
 same time ; and as a cubic foot of 
 water weighs 62^tbs., and a gallon 
 of water 10tbs.,so one horse's power 
 will raise and discharge, at a height 
 of 10 feet, 330 gallons, or 52 T % 
 cubic feet of water in a minute. 
 Consequently this assumed excess 
 of 7260 cubic feet of water fallen 
 upon an acre of land will be raised 
 and discharged at an elevation of 
 10 feet in about two hours and 
 twenty minutes. If the quantity 
 of land be 1000 acres of fen or 
 marsh, with the upland waters all 
 banked out, the excess of rain, ac- 
 cording to the foregoing estimate, 
 will amount to 726,000 cubic feet. 
 A steam-engine of 10-horse power 
 will throw off this water in 232 
 hours, or in less than twenty days, 
 working twelve hours a day. This 
 calculation has been found fully 
 supported in practice. 
 
 Although the rain due to any 
 given month may fall in a few days, 
 yet in such case much of it will be 
 absorbed by the ground ; and the 
 drains must be made of sufficient 
 capacity to receive and contain the 
 rain as it falls ; besides, in case of 
 necessity, the engine may be made 
 to work twenty hours a day in- 
 stead of twelve, until the danger be 
 past. 
 
 The main drains have generally 
 been cut 7 -5 feet deep, and of width 
 sufficient to give them the required 
 capacity to contain the excess of 
 rain, arid to bring the water freely 
 down to the engine. In some in- 
 stances, where the districts are ex- 
 tensive and their length great, it 
 has been found necessary to make 
 them somewhat deeper. 
 
 In all cases where it has been 
 requisite to use steam-power, Mr. 
 Glynn has applied scoop-wheels to 
 raise the water. These scoop-wheels 
 somewhat resemble the undershot 
 wheel of a water-mill, but instead 
 of being turned by the impulse of 
 the water, they are used to lift it, 
 
 161 
 
 and are kept in motion by the 
 steam-engine. 
 
 The floats or ladle-boards of the 
 wheels are made of wood, and fitted 
 to work in a trough or track of 
 masonry ; they are generally made 
 5 feet in length, that is to say, they 
 are immersed 5 feet deep in the 
 water, and their width or horizontal 
 dimension varies from 20 inches to 
 5 feet, according to the power of 
 the engines employed, and the head 
 of water to be overcome. The 
 wheel-track at the lower end com- 
 municates with the main drain, and 
 at the higher end with the river ; 
 the water in the river being kept 
 out by a pair of pointing doors, 
 like the lock-gates of a canal, which 
 close when the engine ceases to 
 work. The wheels themselves are 
 made of cast-iron, formed in parts 
 for convenience of transport. The 
 float-boards are connected with the 
 cast-iron part of the wheel by 
 means of oak-starts, which are 
 stepped into sockets cast in the 
 circumference of the wheel to re- 
 ceive them. 
 
 There are cast-iron toothed seg- 
 ments fitted to the wheel, into 
 which works a pinion fixed upon 
 the crank-shaft of the steam-en- 
 gine. When the head of water in 
 the river or delivering drain does 
 not vary much, it is sufficient to 
 have one speed for the wheel ; but 
 where the tide rises in the river, 
 it is desirable to have two speeds 
 or powers of wheel-work, the one 
 to be used at low rate, the other 
 more powerful combination to act 
 against the rising tide. But in 
 most cases it is not requisite to 
 raise the water more than 3 or 4 
 feet higher than the surface of the 
 land intended to be drained ; and 
 even this is only necessary when 
 the rive"rs are full between their 
 banks, from a continuance of wet 
 weather, or from upland floods. 
 In some instances, the height of 
 the water in the rivers being af- 
 fected by the tide, the drainage by 
 
DRA 
 
 DRAINAGE. 
 
 DRA 
 
 natural outfall can take place only 
 during the ebb ; and here, in casfc 
 of long continuing rains, the natu- 
 ral drainage requires the assistance 
 of mechanical power. 
 
 It has been stated that the main 
 drains have generally been made 
 7^ feet deep, or more in larger dis- 
 tricts, so that the water may never 
 rise higher than within 18 inches 
 or 2 feet of the surface of the 
 ground, and the ladles or float- 
 boards dip 5 feet below the water, 
 leaving a foot in depth below the 
 dip of the wheel, that the water 
 may run freely to it, and to allow 
 for the casual obstruction of weeds 
 in the main drain, which, if it be 
 sufficiently capacious and well 
 formed, will bring down the water 
 to the engine with a descent of 
 3 inches in a mile. Suppose then 
 that the wheel dips 5 feet below 
 the surface of the water in the 
 main drain, and that the water in 
 the river into which this water 
 must be raised and discharged has 
 its level 5 feet above that in the 
 drain, the wheel in such case will 
 be said to have 10 feet head and 
 dip, and ought to be made 28 or 
 30 feet in diameter. 
 
 Mr. Glynn has found it practi- 
 cable to throw out the water against 
 a head of 10 feet with a dip of 5 
 feet, that is to say, 15 feet of head 
 and dip, with a wheel of 35 feet in 
 diameter ; but in another engine, 
 more recently erected, he has made 
 the wheel 40 feet in diameter. 
 The engine that drives this wheel 
 is of 80-horse power, and is situ- 
 ated on the Ten-mile Bank, near 
 Littlepool, in the Isle of Ely. The 
 largest quantity of water delivered 
 by one engine is from Deeping 
 Fen, near Spalding ; this fen con- 
 tains 25,000 acres, and is drained 
 by two engines, one of 80 and one 
 of 60-horse power. 
 
 The 80-horse engine has awheel 
 of 28 feet in diameter, with float- 
 boards or ladles measuring 5^ feet 
 by 5 feet, and moving with a mean 
 
 162 
 
 velocity of 6 feet per second ; so 
 that the section of the stream is 
 27^ feet, and the quantity dis- 
 charged per second 165 cubic feet ; 
 equal to more than 4^ tons of water 
 in a second, or about 16,200 tons 
 of water in an hour. 
 
 It was in 1825 that these two 
 engines were erected, and at that 
 time the district was kept in a half- 
 cultivated state by the help of forty- 
 four windmills, the land at times 
 being wholly under water. It now 
 grows excellent wheat, producing 
 from four to six quarters to the 
 acre. In many districts, land has 
 been purchased at from 10 to 20 
 an acre, by persons who foresaw the 
 consequences of these improve- 
 ments, and which they could nov, 
 sell at from 50 to 70 an acre. 
 This increase in value has arisen, 
 not only from the land beingcleared 
 from the injurious effects of the 
 water upon it, but from the im- 
 proved system of cultivation it has 
 enabled the farmers to adopt. 
 
 The fen-lands in Cambridgeshire 
 and great part of the neighbouring 
 counties are formed of a rich black 
 earth, consisting of decomposed 
 vegetable matter, generally from 
 6 feet to 10 feet thick, although in 
 some places much thicker, resting 
 upon a bed of blue gait, containing 
 clay, lime, and sand. 
 Draining, as applied to lands, towns, 
 and buildings, is the art of drawing 
 or conveying away refuse liquid 
 and other matters, the accumula- 
 tion of which would be detrimental 
 to animal and vegetable existence. 
 
 In that department which re- 
 lates to lands, draining compre- 
 hends also the methods of irriga- 
 ting or supplying water for agri- 
 cultural purposes, for which the 
 natural supply is inadequate. Re- 
 ferring to towns, and buildings, this 
 art includes also, for the purpose of 
 thorough cleansing, the artificial 
 supply of water. 
 
 According to this comprehensive 
 definition, which will be found to 
 
DRA 
 
 DRAINAGE OF LANDS. 
 
 DRA 
 
 have greater practical convenience 
 than any more limited one, Drain- 
 ing comprises observations of the 
 relative levels of districts and of 
 their geological structure ; of the 
 several sources of water, and the 
 amount of their products ; and the 
 construction and arrangement of 
 all the artificial appliances required 
 for the supply, conduct, and dis- 
 posal of water, and for conveying 
 and discharging refuse matters 
 generally. 
 
 The sources of water are rains 
 and the ocean. The former pass- 
 ing into the earth, descend along 
 the lower surfaces, and form streams 
 and rivers ; or penetrate into some 
 permeable media, and accumula- 
 ting in subterranean depositories, 
 form springs. An examination of 
 the superficial and structural fea- 
 tures of the soil enables us to esti- 
 mate the quantity of water present 
 in a district, and to determine the 
 means that will be available for 
 supplying the deficiency or dis- 
 charging the excess. The same 
 observations afford general infor- 
 mation required in order to arrange 
 the artificial channels, drains, 
 sewers, etc., by which the supply 
 and refuse matters are to be con- 
 ducted and disposed of. 
 
 Soils are retentive of water in 
 proportion to their density and 
 compactness. Thus, on clay-lands 
 an excess of water is commonly 
 found, while, from the porous tex- 
 ture of gravel and loose sand, water 
 passes rapidly away, and they are 
 thus kept in a dry condition. 
 
 The size of the channels or 
 drains, by which the water is con- 
 ducted away, will be adapted to the 
 superficial extent to be drained, 
 and the quantity of water due to 
 the district, as computed from its 
 relative position and structure. 
 The construction of the drains will 
 depend upon the materials of the 
 soil, and the proximity of those 
 suitable for the purpose. Generally, 
 covered drains are far preferable to 
 
 163 
 
 open ones ; and those formed with 
 a duct of earthen piping are more 
 durable and economical than any 
 others. The implements used are 
 rods and levels, for measuring dis- 
 tances and ascertaining inclinations 
 of surface; tools for boring the 
 soil, to examine substrata, and de- 
 tect springs, consisting of augers, 
 chisels, punches, etc. ; spades, 
 shovels, and picks of various forms 
 and dimensions ; and hoes, scoops, 
 etc., for clearing out and finishing 
 the form of drains. 
 
 For the draining of towns and 
 buildings, including the artificial 
 supply of water, the best available 
 sources such as rivers and springs 
 are resorted to, and the advan- 
 tageous use of these will require a 
 careful consideration of the quali- 
 ties of the water obtained, and its 
 suitability for domestic and manu- 
 facturing purposes. Arrangements 
 are required for making the water 
 furnished by rains available to the 
 full extent, and rendering it and all 
 other waters fit for use by subsi- 
 dence, filtration, and purification. 
 
 For discharging the refuse mat- 
 ters from houses and other build- 
 ings, and from streets and public 
 thoroughfares, drains and sewers 
 of various forms and materials are 
 to be selected, made of ample di- 
 mensions and permanent construc- 
 tion, with such vertical inclination, 
 and so arranged, that their con- 
 tents shall always have a tendency 
 to run off, and never suffer inter- 
 ference from the discharge of other 
 channels. 
 
 As a final point to be observed 
 in any system of town-drainage, 
 that of the ultimate disposal of the 
 refuse matters is one of the highest 
 importance in both a sanatory and 
 an economical point of view. Col- 
 lected in proper reservoirs, and 
 judiciously treated, these matters 
 may be distributed in fertilizing 
 streams over the fields and the 
 gardens of the suburbs, and will 
 thus realize immense value in im- 
 
DRA 
 
 DRAWBRIDGE. 
 
 DRA 
 
 proved and augmented crops : al- 
 lowed to accumulate in cesspoofs 
 beneath human dwellings, they en- 
 gender malignant and fatal disease, 
 and if finally discharged into a 
 river, by way of getting rid of them, 
 they pollute waters otherwise 
 wholesome, and, in dry seasons, 
 send forth from the banks the most 
 unhealthy gases. 
 
 Drana, a drain or watercourse. 
 
 Draught, In ship draughting,the draw- 
 ing or design by which the ship is 
 to be built, which is generally by a 
 scale of one-fourth of an inch to a 
 foot. 
 
 Draute-chamber, a retiring or with- 
 drawing room. 
 
 Draw-bore, the pinning a mortise and 
 tenon, by piercing the hole through 
 the tenon nearer to the shoulder 
 than the holes through the cheeks 
 from the abutment in which the 
 shoulder is to come in contact. 
 
 Draw-bore pins, pieces of steel in the 
 shape of the frustum of a cone, 
 somewhat tapered, and inserted in 
 handles with the greatest diameter 
 next to the handle, for driving 
 through the draw-bores of a mor- 
 tise and tenon, in order to bring 
 the shoulder of the rail close home 
 to the abutment on the edge of the 
 style : when this is effected, the 
 draw-bore pins, when more than 
 one are used, are taken out singly, 
 and the holes filled up with wooden 
 pegs. 
 
 Drawbridge. All drawbridges are 
 composed of two distinct parts, viz. 
 the platform, which revolves on a 
 horizontal axis, acting as a barrier 
 or gate when in a vertical position, 
 and becoming a bridge when in a 
 horizontal position ; and the con- 
 trivance necessary to balance the 
 platform in every position. The 
 equilibrium should be such that 
 friction is the only force to be 
 overcome in raising or lowering 
 the platform. 
 
 The chief difference between 
 drawbridges lies in the arrange- 
 ment of this latter contrivance; for 
 
 164 
 
 the platforms only differ in small 
 details of construction, which have 
 very little influence on the qualities 
 which are essential to the arrange- 
 ment of the balancing apparatus. 
 These qualities remain the same, 
 whether the drawbridges are used 
 for closing communications in for- 
 tified works, or merely for forming 
 passages across navigable canals. 
 They are principally as follows : 
 
 1st. The whole system should 
 possess sufficient strength to be 
 perfectly free from danger in all 
 positions and at all times, and 
 should therefore be constructed 
 of solid and lasting materials. 
 
 2nd. A small number of men 
 should be able to raise or lower 
 the bridge in a short space of time. 
 This quality requires all the parts 
 to be in equilibrium when friction 
 is not considered. 
 
 3rd. The machinery for raising 
 and lowering the bridge should not 
 obstruct the communications either 
 in front or in rear of the buttresses 
 of the gateway where it is placed ; 
 and also the space formed by rais- 
 ing the bridge should be as wide 
 as possible, for this space consti- 
 tutes the chief use of the bridge. 
 
 4th. The counterpoise and the 
 machinery attached to it should be 
 raised as little as possible above 
 the platform when vertical, in or- 
 der that it may not be much ex- 
 posed to an enemy's fire, and that 
 it may be easily covered by the ad- 
 vanced works ; besides that, by 
 raising it, the expense of construct- 
 ing and the inconvenience of work- 
 ing the machinery are increased, 
 and the strength of the gateway or 
 postern is sometimes diminished. 
 
 5th. The counterpoise and its 
 machinery should not be much be- 
 low the level of the ground, and 
 particularly very little below the 
 level of the surface of the water 
 in wet ditches. At all events, the 
 descending parts should be enclosed 
 in narrow shafts of masonry secure 
 from damp. In order not to weaken 
 
DRA 
 
 DREDGING. 
 
 DRI 
 
 the postern walls, they should be 
 at least 3 feet in rear of them. 
 
 Drawing is the art of representing 
 objects on a flat surface by lines 
 describing their forms and contours 
 alone, independently of colour or 
 even shadow, although the latter is 
 closely allied with drawing, both in 
 practice and theory. 
 
 Drawings in pencil are sometimes re- 
 quired to be fixed : this can be 
 done by using water-starch made 
 to the consistency of that employed 
 by laundresses : it should be ap- 
 plied with a broad camel's hair 
 brush, as in varnishing. Isinglass, 
 size, and rice-water are sometimes 
 used, but are not so good as the 
 first-named substance. 
 
 Dredge's Suspension Bridge consists 
 in making the chains of sufficient 
 magnitude and strength at the 
 points of suspension to support 
 with safety the greatest permanent 
 and contingent load to which, un- 
 der the circumstances of locality, 
 they are ever likely to be exposed ; 
 and from thence, to taper or dimi- 
 nish them gradually to the middle 
 of the bridge, where the strain be- 
 comes essentially evanescent. The 
 gradual diminution of the chains, 
 however, is not the only peculiarity 
 which characterizes this mode of 
 construction, and marks its utility. 
 The suspending-rods or bars that 
 support the platform, or roadway, 
 instead of being hung vertically or 
 at right angles to the plane of the 
 horizon, are inclined to it in angles 
 which vary in magnitude from the 
 abutments to the middle of the 
 bridge, where the obliquity, as well 
 as the stress upon the chains, at- 
 tains its minimum value. 
 
 Dredging machines, mechanical con- 
 trivances placed in the hull of a 
 vessel, and floated in situations for 
 the dredging and clearing away of 
 deposited matter from the beds of 
 rivers, canals, harbours, basins, etc. 
 Some machines for these purposes 
 are to be compared to harrows or 
 shovels, which loosen the deposit 
 
 165 
 
 preparatory to its removal either 
 by the action of the tide or stream ; 
 but for the more general purposes 
 of dredging, vast improvements 
 have been effected. The machinery 
 of the best construction is described 
 in Weale's ' Quarterly Papers on 
 Engineering.' 
 
 Dressings, the mouldings and sculp- 
 tured decorations of all kinds which 
 are used on the walls and ceilings 
 of a building for the purpose of 
 ornament. 
 
 Drift, a piece of hardened steel, 
 notched at the sides and made 
 slightly tapering : it is used for 
 enlarging a hole in a piece of metal 
 to a particular size by being driven 
 through it. 
 
 Drift, the horizontal force which an 
 arch exerts with a tendency to 
 overset the piers from which it 
 springs. 
 
 Drifts, in the sheer draught, are 
 where the rails are cut off and 
 ended with a scroll. Pieces fitted 
 to form the drifts are called drift- 
 pieces. 
 
 Driftway, in mining, is a passage cut 
 under the earth from shaft to shaft. 
 
 Drill, a tool for cutting a circular 
 hole in a piece of metal. 
 
 Drilling machine, a machine for cut- 
 ting circular holes in metal by 
 means of a revolving drill. 
 
 Drilling, the art of boring small holes. 
 Drilling may be effected in a lathe. 
 The drill is screwed upon the spin- 
 dle, so that its point shall turn ex- 
 actly opposite that of the screw in 
 the shifting head. Various inge- 
 nious improvements have recently 
 been made. 
 
 Drip, the projecting edge of a mould- 
 ing channeled beneath, so that the 
 rain will drip from it : the corona 
 of the Italian architects. 
 
 Dripstone, called also the 'label,' 
 4 weather moulding,' and ' water 
 table,' a projecting tablet or mould- 
 ing over the heads of doorways, 
 windows, archways, niches, etc. 
 
 Driver, the foremost spur in the 
 bulge-ways, the heel of which is 
 
DRI 
 
 DRUMMOND LIGHT. 
 
 DUT 
 
 fayed to the foreside of the fore- 
 most poppet, and the sides placed 
 to look fore and aft in a ship. 
 
 Driver, the bent piece of iron fixed in 
 the centre chuck, and projecting 
 over it to meet the carrier, and 
 drive it forward. 
 
 Driving shaft, any shaft which gives 
 motion to another shaft. 
 
 Driving springs, the springs fixed 
 upon the boxes of the driving axle 
 of a locomotive engine, to support 
 the weight and to deaden the 
 shocks caused by irregularities in 
 the rails. 
 
 Driving wheels, the large wheels of a 
 locomotive engine, which are fixed 
 upon the crank-axle or main shaft 
 of the engine. 
 
 Drop, in architecture, is an ornament 
 of the columns of the Doric order, 
 representing drops or little bells 
 under the triglyphs. 
 
 Drum, in architecture, the bell-formed 
 part of the Corinthian and Compo- 
 site capitals. 
 
 Drum, a hollow cylinder fixed on a 
 shaft, for driving another shaft by 
 a band. 
 
 Drummond light, a peculiar light in- 
 vented by the late Captain Drum- 
 mond, called a heliostat, which re- 
 flected the sun's rays in sufficient 
 all tin dance to render the station 
 which was to be observed visible. 
 This invention obviated the diffi- 
 culty of distinguishing the stations 
 chosen for the angular points of 
 the triangles in a geodesical sur- 
 vey : where those stations are many 
 miles asunder, it is necessary to 
 have recourse to illuminations even 
 in daytime. 
 
 Dry oil, nearly colourless, may be ob- 
 tained by combining linseed or 
 nut oil with litharge, and tritura- 
 ting them together for a consider- 
 able time ; this will produce a yel- 
 lowish creamy substance, which 
 being allowed to rest, soon becomes 
 clear ; but if there be not time to 
 wait, this fluid may be filtered 
 through blotting paper : it is then 
 transparent, but with a little colour, 
 
 166 
 
 which soon goes off when exposed 
 to the light. 
 
 Druxey, timber in a state of decay, 
 with white spongy veins. 
 
 Dryness is a term by which artists 
 express the common defect of the 
 early painters in oil, who had but 
 little knowledge of the flowing con- 
 tours which so elegantly show the 
 delicate forms of the limbs and the 
 insertions of the muscles ; the flesh 
 in their colouring appearing hard 
 and stiff, instead of expressing a 
 pleasing softness. The draperies 
 of those early painters, and parti- 
 cularly of the Germans, concealed 
 the limbs of the figures, without 
 truth or elegance of choice ; and 
 even in their best masters, the dra- 
 peries very frequently either de- 
 meaned or encumbered the figures. 
 
 Dry-rot, a disease affecting timber, 
 and particularly the oak employed 
 for naval purposes. Many contri- 
 vances are employed as remedies 
 which have recently been patented, 
 and have been successfully applied. 
 
 Dub, to work with the adze. 
 
 Ductilimeter, an instrument for com- 
 paring the ductility of lead, tin, etc. 
 
 Ductility is that property of bodies 
 which admits of their being drawn 
 out in length, while their diameter 
 is diminished, without any actual 
 fracture. Gold, silver, platinum, 
 iron, copper, zinc, tin, lead, nickel, 
 are ductile in the order here given : 
 wire-drawing depends on ductility. 
 
 Duma (in Cornish), frames of wood 
 like the jambs of a door or the 
 frame of a window ; set in loose 
 ground in adits and places that are 
 weak and liable to fall in or tumble 
 down. 
 
 Dungeon, a place of incarceration, 
 formerly the principal tower or 
 keep of a castle : it was always 
 the strongest and least accessible 
 part of a building. 
 
 Durbar (Persian), a court or building 
 where the sovereign or viceroy 
 gives audience. 
 
 Dutch Pink, English and Italian 
 Pinks, are bright yellow colours 
 
BUT 
 
 DYNAMICS. 
 
 DYN 
 
 used in distemper and for paper- 
 staining, and other ordinary pur- 
 poses. The pigment called ' stil,' 
 or ' stil de grain,' is a similar pre- 
 paration, and a very fugitive yel- 
 low, the darker kind of which is 
 called Brown Pink. 
 
 Dutch School of Painting. This 
 school of art cannot be said to 
 possess the perfections that are to 
 be observed in the Flemish school ; 
 their subjects are derived from the 
 tavern, the smith's shop, and from 
 vulgar amusements of the rudest 
 peasants. The expressions are suf- 
 ficiently marked ; but it is the ex- 
 pression of passions which debase, 
 instead of ennobling human nature. 
 It must be acknowledged, at the 
 same time, that the Dutch painters 
 have succeeded in several branches 
 of the art. If they have chosen 
 low subjects of imitation, they have 
 represented them with great exact- 
 ness ; and truth must always please. 
 If they have not succeeded in most 
 difficult parts of the chiaro-oscuro, 
 they at least excel in the most 
 striking, such as in light confined 
 in a narrow space, night illumi- 
 nated by the moon, or by torches, 
 and the light of a smith's forge. 
 The Dutch understand the grada- 
 tions of colours. They have no 
 rivals in landscape painting, con- 
 sidered as the faithful represen- 
 tation of a particular scene ; but 
 they are far from equalling Titian, 
 Poussin, Claude Lorraine, etc., who 
 have carried to the greatest per- 
 fection the ideal landscape ; and 
 whose pictures, instead of being 
 the topographical representation of 
 certain places, are the combined 
 result of everything beautiful in 
 imagination or in nature. 
 
 Dyeing is the art of staining textile 
 substances with permanent co- 
 lours. 
 
 Dyke, in coal mining, the banks of 
 basalt or whin, by which the coal 
 strata are frequently divided. 
 
 Dynamics, the science of moving 
 powers, or of the action of forces 
 
 167 
 
 on solid bodies when the result of 
 that action is motion. 
 
 GENERAL DEFINITIONS. 
 
 1. The mass of a body is the 
 quantity of matter of which it is 
 composed, and is proportional to 
 its weight, or to the force which 
 must be applied to the body to 
 prevent its gravitating to the earth, 
 and which, being greater or less 
 as the mass is greater or less, we 
 regard as a measure of the mass 
 itself. 
 
 2. Density is a word by which 
 we indicate the comparative close- 
 ness or otherwise of the particles 
 of bodies, and is synonymous with 
 the term specific gravity. Those 
 bodies which have the greatest 
 number of particles, or the great- 
 est quantity of matter, in a given 
 magnitude, we call most dense; 
 those which have the least quan- 
 tity of matter, least dense. Thus 
 lead is more dense than freestone ; 
 
 freestone more dense than oak; 
 and oak more dense than cork. 
 
 3. The velocity with which a 
 body in motion moves, is measured 
 by the space over which it passes in 
 any given time ; the unit usually 
 assumed being one second. 
 
 4. If the body passes over an 
 equal space in each successive unit 
 of time, the body is said to move 
 uniformly, or to have a uniform 
 velocity, and the measure of such 
 velocity is the space actually passed 
 over by the body in each second. 
 
 5. If, however, the body passes 
 over a greater space in each suc- 
 cessive second than it did in the 
 preceding, then it is said to move 
 with an accelerated velocity : when 
 the differences between the spaces 
 moved over in any two successive 
 seconds is the same, at whatever 
 period of the body's motion they 
 be taken, or in other words, when 
 the successive spaces form an arith- 
 metical progression, the body is 
 said to move with a uniformly ac- 
 celerated velocity ; but when the 
 spaces passed over in successive 
 
DYN 
 
 EARLY ENGLISH ARCHITECTURE. 
 
 EAR 
 
 seconds increase according to any 
 other law, the body is then said to 
 have its velocity variably accele- 
 rated. 
 
 6. If, on the other hand, the 
 body passes over a smaller space in 
 each successive second than it did 
 in the preceding, then it is said to 
 move with a retarded velocity ; 
 which, if the successive spaces 
 form a decreasing arithmetical 
 series, is said to be uniformly re- 
 tarded ; if otherwise, it is said to 
 be variably retarded. 
 
 7. The velocity of a body whose 
 motion is variable is expressed at 
 any moment by the space which it 
 would pass over in a second, if its 
 velocity at the moment spoken of 
 were to continue uniform for that, 
 period. , 
 
 8. Mechanical effect is measured 
 by the product of the mass or 
 weight of the body into the space 
 over which it has been moved ; no 
 
 regard being had to the time occu- 
 pied. The unit of mechanical effect 
 is a weight of one pound raised 
 through a space of one foot. 
 
 9. The momentum of a body in 
 motion means the mechanical effect 
 which such a body will produce in 
 a moment (or second) of time, and 
 varies as the weight of the body 
 multiplied by its velocity. 
 
 10. The vis viva of a body in 
 motion is the whole mechanical 
 effect which it will produce in 
 being brought to a state of rest, 
 no regard being had to the time in 
 which the effect is produced, and 
 it varies as the weight of the body 
 multiplied by the square of its 
 velocity. 
 
 Dynamometer, an instrument which 
 measures anything to which the 
 name of power has been given, 
 whether that of an animal or other- 
 wise. 
 
 Dysodile, a papyraceous brown coal. 
 
 E. 
 
 Early English Architecture, the first 
 of the pointed or Gothic styles of 
 architecture used in England. It 
 immediately succeeded the Norman 
 towards the end of the 12th cen- 
 tury, and gradually merged into 
 the Decorated at the end of the 
 13th. The mouldings consist of 
 alternate rounds and deeply cut 
 hollows, with small fillets, pro- 
 ducing a strong effect of light and 
 shadow. The arches are usually 
 equilateral or lanced - shaped, 
 though drop-arches are frequently 
 met with, and sometimes point- 
 ed segmented arches: trefoil and 
 cinquefoil arches are also often 
 used in small openings and panel- 
 ings. The doorways of this style, 
 in large buildings, are often divided 
 into two by a single shaft or small 
 pin, with a quatrefoil or other 
 ornament. The windows are al- 
 most universally of long and narrow 
 proportions, and are used singly, 
 or in combinations of two, three, 
 
 168 
 
 five, and seven : when thus com- 
 bined, the space between them 
 sometimes but little exceeds the 
 width of the mullions of the latter 
 styles. Groined ceilings are very 
 common in this style. The pillars 
 usually consist of small shafts ar- 
 ranged round a larger circular pier, 
 but others of a different kind are 
 sometimes found. The capitals 
 consist of plain mouldings, or are 
 enriched with foliage and sculpture 
 characteristic of the style. 
 
 Earthwork. The patented excavator, 
 an American invention, is capable, 
 it is said, of cutting and levelling 
 earthwork for the making of rail- 
 ways and for other works at a cost 
 considerably below manual labour, 
 and has the additional advantage 
 of saving much time : it forms an 
 important consideration in railway 
 making, but little used in England. 
 
 Earth-table, the lowest course of stone 
 that is seen in a building, level with 
 the earth. 
 
EAS 
 
 EFFECTS OF BUILDINGS. 
 
 EFF 
 
 Easel, for painters, the frame on 
 which the canvas is laid, stretched 
 for painting. 
 
 East Indian Black-wood grows to an 
 immense size, and is much used 
 for making furniture. 
 
 Easter, a movahle feast held in com- 
 memoration of the Resurrection. 
 Being the most important and most 
 ancient in observance, it governs 
 the other movable feasts through- 
 out the year. 
 
 Eaves, the lower edge of a sloping 
 roof which overhangs the face of 
 a wall, for the purpose of throwing 
 off the water. 
 
 Ebony wood is of several colours, as 
 yellow, red, green, and black. The 
 latter is always preferred, and is 
 much used. It is imported princi- 
 pally from the East, and is used for 
 cabinet, mosaic, and turnery work, 
 for flutes, handles of doors, knives, 
 surgeons' instruments, piano-forte 
 keys, etc. 
 
 Eborarius, a term applied by tbe Ro- 
 mans to a kind of ivory-work. 
 
 Eccentric, or Excentric, a circular disc 
 revolving within a strap or ring, 
 and having its axis of revolution 
 on one side of the centre. It is 
 used as a substitute for a crank for 
 giving a reciprocating motion to 
 the slide-valve or to the feed-pump 
 of a steam-engine. 
 
 Eccentrics are circular sheaves with a 
 hole for the driving-wheel axle, 
 about two inches out of the centre of 
 the sheave of a locomotive-engine, 
 which thus makes it project some 
 four inches more from the centre of 
 the driving axle on one side than 
 on the other. It is this eccentricity 
 of motion which works the slide- 
 valve gear and pumps in a very sa- 
 tisfactory manner. Eccentrics are 
 fitted in two parts, and secured to 
 the axle by a hoop and setbolts. 
 
 Eccentric hoops, hoops fitted round 
 the projecting part of the eccentric 
 sheaves of a locomotive-engine, to 
 strengthen them. 
 
 Eccentric rod and strap, the rod, the 
 strap end of which encircles the 
 
 169 
 
 eccentric sheave, and the other end 
 connects it with the quadrant, or 
 rocking-shaft, according to the 
 class of a locomotive-engine. In 
 some engines the end is forked to 
 go on the stud of the rocking- 
 shaft, and opens out something 
 like the letter V ; or when only 
 one rod is used for both back and 
 forward movements, it resembles 
 the letter X. In other engines it 
 is attached to the quadrants by a 
 bolt, one rod for forward gear, and 
 another rod for backward gear. 
 
 Eccentric rod, the rod connecting the 
 eccentric strap to the lever which 
 moves the slide-valve. 
 
 Eccentric strap, a brass ring formed 
 by two pieces bolted together, and 
 fixed to the eccentric rod : the 
 ring fits a grooved part in the cir- 
 cumference of the eccentric. 
 
 Echinus, the egg and anchor, or egg 
 and tongue ornament found carved 
 on the ovolo, in classical architec- 
 ture. 
 
 Echinus, a member of the Doric capi- 
 tal ; so called from its resemblance 
 to the echinus, or large vase, in 
 which drinking-cups were washed. 
 
 Ecphora, the projection of any mem- 
 ber or moulding before the face of 
 the member or moulding next be- 
 low it. 
 
 Eduction pipe, the pipe from the ex- 
 haust passage of the cylinder to the 
 condenser. 
 
 Effect is the art of giving to a draw- 
 ing a striking appearance, or so- 
 lemnity, awe, sadness, mirth, or 
 tranquillity, by a judicious combi- 
 nation of objects, and by strong 
 light and shadow. It is a faithful 
 representation of the appearance of 
 nature, best seen under certain cir- 
 cumstances and at certain times, 
 such as morning effect, evening 
 effect, twilight effect, and stormy 
 effect, torch-light and candle-light 
 effects, etc. 
 
 Effects of buildings. " The site adapt- 
 ed for buildings, and the accompa- 
 niments of terraces, gardens, and 
 other decorations to set off their 
 
EGG 
 
 EGYPTIAN ARCHITECTURE. 
 
 ELA 
 
 architectural designs, are subjects 
 for consideration in which we are 
 influenced by the desire to raise 
 and extend the theory and practice 
 to what we consider belongs to the 
 art. It was in Italy, when the fine 
 arts were in perfection, that the 
 laying out great villas was prac- 
 tised by artists who often combined 
 the practice of painting and archi- 
 ture ; and until it be adopted in 
 England, the designs of the archi- 
 tect never will have justice done to 
 them in the execution. Our parks 
 may be beautiful, our mansions 
 faultless in design ; but nothing is 
 more rare than to see the two pro- 
 perly connected. Let the architect 
 by study and observation qualify 
 himself to include in his art the 
 decorations around the immediate 
 site of the intended building, toge- 
 ther with its interior adornment, 
 furniture, and upholstery, and the 
 growing taste among the gentry of 
 England will second such laudable 
 efforts." 
 
 Egg, in architecture, an ornament of 
 that form, cut in the echinus or 
 quarter round. 
 
 Egyptian Architecture had its origin 
 2222 years before Cbrist, and ad- 
 vanced and flourished under dif- 
 ferent dynasties. The first includes 
 the two great dynasties of Theban 
 princes, who governed Egypt dur- 
 ing her " most high and palmy 
 state," when Thebes sent forth her 
 armies to distant conquest. In the 
 second period is comprised the 
 erection of the Pyramids. The 
 third includes the reigns of the 
 Ptolemies and earlier Caesars, un- 
 der whom Egyptian architecture 
 flourished in a second youth, and 
 almost attained its original splen- 
 dour. Egyptian architecture, so 
 massive and so sombre, with its 
 vast aisled halls without windows, 
 its close files of gigantic columns, 
 and its colossal statues, owes many 
 characteristic forms and effects to 
 earlier cavern temples in Ethiopia. 
 One of the most striking peculiari- 
 
 170 
 
 ties of the style is the pyramidal 
 character of the ascending lines : 
 it is observed in the outline of the 
 portal and the gigantic pylon, in 
 walls, doorways, pedestals, and 
 screens : it pervades the whole 
 system, and must have been occa- 
 sioned by circumstances connected 
 with its origin. The representa- 
 tions given in ancient paintings 
 show a remarkable love of unifor- 
 mity of arrangement of their do- 
 mestic houses and gardens. In an 
 ordinary house a number of cham- 
 bers were ranged round a rectan- 
 gular court, as at Pompeii. The 
 larger mansions sometimes consist- 
 ed of an assemblage of such courts, 
 the whole occupying a square or 
 oblong plot. Sometimes a central 
 group of buildings was surrounded 
 by a narrow court. A spacious area 
 often extended from front to rear, 
 with a chief and side entrances at 
 either end : the exterior had no- 
 thing of the ponderous character 
 of temple structures, which would 
 have been ill-suited to the wants 
 and festivities of social life. Houses 
 two and three stories high were 
 common ; but large mansions ap- 
 pear to have been low and extensive 
 rather than lofty. The terraced top 
 was covered by an awning or roof, 
 supported on light graceful columns. 
 Edioffraph, an instrument contrived 
 forthe purpose of copying drawings. 
 Elceing, in ship-building, a piece fitted 
 to make good a deficiency in length 
 on the lower part of the supporter 
 under the cat-head, etc. ; likewise 
 the piece of carved work under the 
 lower end of the quarter-piece at 
 the aft part of the quarter-gallery. 
 Elastic, springy, having the power of 
 returning to the form from which 
 it was distorted. 
 
 Elastic force of steam. The French 
 reckon an atmosphere to be equal 
 to a column of mercury '76 of a 
 metre in height, which is only 
 29'92 inches, and the boiling point 
 of their thermometer is adapted 
 thereto ; whereas, since about the 
 
ELB 
 
 ELECTRIC TELEGRAPH. 
 
 ELE 
 
 commencement of the present cen- 
 tury, the English have reckoned it 
 to be 30 inches. This circumstance 
 accounts in some degree for their 
 scale of temperatures differing from 
 Mr. Southern's. 
 
 The French account of the occa- 
 sion of making their experiments 
 on the temperatures corresponding 
 to different elasticities of steam, in 
 1829, contains the following pas- 
 sage : " Science did not then pos- 
 sess this knowledge, and engineers 
 appointed to superintend the con- 
 struction of steam-engines had no 
 other guidance than some discor- 
 dant measures upon the tempera- 
 tures which correspond to the elas- 
 ticities between one and eight at- 
 mospheres : for higher pressures 
 there was no result of direct expe- 
 riments, nor any theory which 
 could supply the deficiency." 
 
 Elbow, in architecture, an obtuse 
 angle of a wall, building, etc. 
 
 Elder-wood. The branches of the elder 
 contain a very light kind of pith, 
 which is used, when dried, for elec- 
 trical purposes ; the wood is also 
 frequently used for carpenter's 
 rules, weavers' shuttles, etc. 
 
 Electric Telegraph in India. Accord- 
 ing to Dr. O'Shaughnessy's Report 
 on the operations of the Electric 
 Telegraph Department in India, the 
 total number of despatches trans- 
 mitted from 1st February, 1855, to 
 31st January, 1856, was 9971, of 
 which 8533 were private, and 1438 
 public service despatches. Of 
 these by far the greater part was 
 between Bombay and Calcutta, and 
 Bombay and Madras, showing that 
 the commercial intelligence re- 
 ceived by mail either from Europe 
 or China is what gives the chief 
 employment to the telegraph. Of 
 the paid messages, not less than 
 2864 were sent by native corre- 
 spondents. There is every reason 
 to conclude that the future income 
 of the department will increase. 
 While the European community are 
 comparatively a very limited class, 
 
 the native merchants, bankers, 
 fundholders, and gentry, may be 
 considered as innumerable. The 
 number of native correspondents 
 is accordingly increasing daily. 
 Not only do they use the lines for 
 financial business, but on the most 
 delicate and secret matters affect- 
 ing family arrangements, betrothals, 
 marriages, and other domestic af- 
 fairs, of which they treat with an 
 absence of all disguise which is 
 almost beyond belief. The receipts 
 have averaged 10,089-1-2 rupees 
 per month; of this the Calcutta 
 office alone returns monthly 4433- 
 12 rupees. The service despatches 
 being estimated at the same rate, 
 the work done in the year is not 
 less than two lacs of rupees. When 
 the whole line has acquired public 
 confidence by being found punctual 
 and accurate, the business will 
 vastly increase. Terrible as are 
 the thunderstorms which prevail 
 over nearly all India, the precau- 
 tions taken to prevent injuries to 
 the offices or persons employed 
 have proved completely successful, 
 though the lines have been re- 
 peatedly struck. 
 
 Electrical state of the atmosphere. 
 The electrical condition of the air 
 in serene and tempestuous weather 
 has been too much overlooked by 
 meteorologists. The atmosphere 
 is generally found to be in an elec- 
 trical state. The apparatus for 
 these observations is simply a me- 
 tallic rod, insulated at its lower 
 extremity, elevated at some height 
 above the ground, arid communi- 
 cating with an electroscope. Wheni 
 the amenity of the weather will, 
 permit, a kite should be raised, in 
 the string of which a metallic wire 
 should be interwoven ; this will 
 collect the electricity of the higher 
 regions of the air. The atmospbere 
 is usually found to be positively 
 electrified, and its electricity is 
 stronger in the winter than in the 
 summer, and during the day than 
 in the night. 
 
 171 
 
 i 2 
 
ELE 
 
 ELEMENTARY INSTRUCTION. 
 
 ELE 
 
 Electricity (from elecirum, amber), 
 was a name given at first to some 
 peculiar effects observed on rub- 
 bing that substance, and gradually 
 extended to an immense collection 
 of facts of a similar kind, as well 
 as to the cause of these effects, 
 whatever it may be, and to the 
 science which investigates their 
 laws. 
 
 This science is sometimes divided 
 into five or six branches, according 
 to the modes in which electric ef- 
 fects may be brought about. The 
 term atmospheric electricity applies 
 to that which is naturally exhibited 
 at nearly all times, but especially 
 in thunderstorms; common or 
 frictional electricity, to that deve- 
 loped by mere mechanical actions ; 
 galvanism or voltaic electricity, to 
 that developed by chemical action ; 
 ^errwo-electricity, by the action of 
 heat ; wo^w^o-electricity, by that 
 of magnetism ; and animal electri- 
 city, by the will of certain fishes, 
 which use this power as a defence. 
 A more modern and comprehensive 
 division is into 1. Electro-statics, 
 or tensional electricity, referring to 
 those effects in which the agency 
 seems to have the equilibrium of 
 its distribution disturbed, so as to 
 be excessive or deficient in certain 
 bodies, making them appear in dif- 
 ferent states. 2. Electro-dynamics, 
 or current electricity, describing 
 those effects in which the agency 
 appears to be moving from place to 
 place, and displaying momentum. 
 
 Electrum, from the Greek, a name 
 given to amber, or to a mixture 
 of metals composed of gold and 
 silver. 
 
 Elecirum, argentiferous gold; an alloy 
 of silver. 
 
 Elegance, in a design, is a manner 
 which embellishes and heightens 
 objects, either as to their form or 
 colour, or both, without destroying 
 or perverting truth. 
 
 Elementary Instruction. Before en- 
 tering into practice, it will be ne- 
 cessary to bear the following rules 
 
 172 
 
 and tables always in mind; and 
 although we are to suppose every 
 one already well acquainted with 
 them, they may yet possibly be 
 found useful and essential here. 
 
 SIGNS AND MARKS. 
 
 + Plus, or more : the sign of ad- 
 dition ; as 5 + 6 = 11. 
 
 Minus, or less: the sign of sub- 
 traction, as 20 5 = 15. 
 
 x Multiply by : the sign of multi- 
 plication, as 8 x 9 = 72. 
 
 -5- Divide by : the sign of division, 
 as 16-7-4*=4. 
 
 = Equal to : the sign of equality, 
 as 27 cubic feet= I cubic yard. 
 
 * \ Proportion : the sign of propor- 
 tion, as 3 : 6 : : 8 : 16. 
 
 f Fraction. 
 
 $ Square root. <!/ Cube root. 
 
 LINEAL MEASURE. 
 
 7*92 inches .... 1 link. 
 12 inches .... 1 foot. 
 
 3 feet 1 yard. 
 
 5 yards. 1 rod, pole, or perch. 
 
 4 poles, 100 links . 1 chain. 
 40 poies, 10 chains . 1 furlong. 
 
 8 furlongs,! 760 yards,! mile. 
 80 chains, 8000 links 1 mile. 
 
 SaUARE OR SUPERFICIAL MEASURE. 
 
 144 square inches 1 square foot. 
 9 square feet . 1 square yard. 
 
 30* square yards { > 
 
 40 perches . . 1 rood. 
 
 4 roods ... 1 acre. 
 
 640 acres ... 1 square mile. 
 
 CUBIC OR SOLID MEASURE. 
 
 1728 solid inches . 1 cubic foot. 
 
 27 solid feet . . 1 cubic yard. 
 
 Proceeding to the various forms 
 
 of plane surfaces, and the methods 
 
 A 
 
ELE 
 
 ELEMENTARY INSTRUCTION. 
 
 ELE 
 
 of measuring them, am! beginning 
 with the square, which has four 
 equal sides and four right angles, 
 as A, B, c, D, Rule: Multiply the 
 given side hy itself, and the product 
 is the area required. Ex. 12 x 12 
 = 144. 
 
 The next figure will he a paral- 
 lelogram, or oblong square. Rule : 
 Multiply the length by the breadth, 
 
 and the product gives the area. 
 Ex. 18'0"x6'0"=108'0". 
 
 The next figure will be a rhom- 
 bus, which has four sides all equal, 
 but no right angle. Rule : Multi- 
 
 ply the base by the perpendicular 
 height, and the product is the area. 
 Ex. 16'0"x 14'0" = 224'0". 
 
 The next figure will be the 
 rhomboid, which has its two sides 
 equal and parallel, but no right 
 angle : it is a long square pushed 
 
 aside. Rule : Multiply the longer 
 side by the perpendicular height 
 or breadth, and the product is the 
 area. Ex. 18' 0" x 5' 6" = 99' 0". 
 The next will be a right-angled 
 
 triangle, having one of its angles a 
 true square, or just 90 degrees. 
 Rule: Multiply one of the legs 
 forming the right angle by half 
 the other ; the product is the area. 
 Ex. 16'0"^2 = 8 x 20'0" = 160'0". 
 The next figure will be a tri- 
 angle. Rule: Multiply the longest 
 side by one- half the perpendicular, 
 
 and the product is the content. 
 Ex. 14' 0"-*-2 = 7' 0"x24' 0" = 
 168' 0", area required. 
 
 The next figure will be the tra- 
 pezium, which consists of four un- 
 equal sides, and four unequal an- 
 gles ; it is, indeed, two triangles, 
 and may be measured at twice, as 
 shown in the preceding triangle, or 
 
 by this Rule : Multiply the diagonal 
 by one-half the sum of the two 
 perpendiculars. Ex. 8' 0" + 4' 0" 
 = 12' 0" -f- 2 = 6'0" x 20' 0" = 
 120' 0", the area required. 
 
 The next figure will be the area 
 of a circle. Rule : Square the 
 diameter, and multiply that pro- 
 
 173 
 
ELE 
 
 ELEMENTARY INSTRUCTION. 
 
 ELE 
 
 duct by /ba4, a uccimai, uuu il\,\ 
 prod ict "-ill he the portent. Fx. 
 12' 0"x 12' O'=144' 0"x -7854 = 
 113-0. 76. 
 
 Th; next dia- 
 gram will be a 
 segment or part 
 of a section of a 
 circle : to mea- 
 sure this, mul- 
 tiply half the 
 sum of the two 
 arches by one 
 of t c; ends, and 
 the product will 
 giv ; the area. 
 Ex 24' 0" + 
 18' 0" = 42' 0" 
 -4-2 = 21'0"x 
 2' 0" = 42' 0", 
 w lich is the 
 ar a required. 
 
 Where the figure is found of 
 the shape annexed, with two right 
 ang es, and the sides not parallel, 
 
 instead of dividing it and measuring 
 it as a parallelogram and an angle, 
 take the mean of the two per- 
 pendiculars, and multiply by the 
 length ; the product will give the 
 area required. Ex. 12' 0" + 8' 0" 
 = 20' 0"-r-2 = 10' 0"= x 32' 0" = 
 320' 0". 
 
 It is now necessary to take into 
 consideration the methods of mea- 
 suring solid or cubic bodies ; for 
 example, to begin with a cube, viz. 
 a solid bounded by six square sides, 
 similar to a die 
 
 Rule : Mul- ' 
 tiply the side 
 by itself, and 
 the product by 
 the side again ; 
 the last pro- 
 duct willbethe 
 solid content. Ex. 6' 0" x 6' 0" = 
 36' 0" x 6' 0" = 2]6' 0" cubic feet. 
 
 The next figure 
 is the parallelo- 
 pipedon, or ob- 
 long cube. Rule: 
 Multiply the 
 breadth by the 
 depth, and that 
 product by the 
 length ; this last 
 product will be 
 the content of it. 
 Ex. 6'0"x8'0" 
 = 48'0"x32'0" 
 = 1536' 0" = 
 t he required con- 
 tent of 'the paral- 
 lelopipedon. 
 
 Next proceed 
 the prism, to measure 
 which, find the area at 
 the end, multiply that 
 by the length. and that 
 product is the content. 
 Ex. Theperpendicular 
 height, 6' 0" -f- 2 = 
 3'0"x 12'0'^36'G" 
 x32' 0"=1152' 0". 
 
 The inclined plane 
 and wedge may be 
 measured by the same 
 rule as the prism ; but 
 the readier way is to 
 multiply one-half of 
 the thickness of the 
 base bv its width, and 
 
 \ 
 
 17-1 
 
ELE 
 
 ELEMENTARY INSTRUCTION. 
 
 ELO 
 
 the perpendicular or length. 
 Q" x 15' 0" = 45' 0" x 20' 0" 
 
 that b 
 
 Ex. 
 
 = 900' 0" = content of inclined 
 
 plane. 
 
 This figure will be found in all 
 earth-work, passing from cutting 
 to embankment. 
 
 Again, 6'0"x 15' 0" = 90' 0" x 
 20' O''=1800' 0", content of the 
 wedge. 
 
 The next figure is a square pyra- 
 mid, and the one-half of which is 
 a very prominent formation in 
 banks, and is measured by multi- 
 
 plying the area of the base by one- 
 third the height or length. Ex. 
 6' 0" x 6' 0" = 36' 0" x 6' 0" = 
 210' 0" content. 
 
 Arriving now at the cylinder, 
 this is measured by multiplying 
 
 s 
 
 the area of the base or end by the 
 length. Ex. 12' 0" x 12' 0" = 
 144' 0"x -7854 = 113-0976 x 20' 0" 
 = 2260' 0". 
 
 The cone is also measured by 
 multiplying the area of the base by 
 one-third the perpendicular height. 
 Ex. 12' 0" x 12' 0" = 144' 0" x 
 7854 = 113' 0"x 6' 8"= 753' 4". 
 
 1 7?i 
 
 The next figure is the frustum 
 of a square pyramid, which also is 
 a form peculiar in 
 embankments and 
 cuttings. Rule : 
 To four times the 
 area of the mean 
 base add the area 
 of each end, which 
 divide by 6 ; mul- 
 tiply the product 
 by the length, you 
 will find the con- 
 tents. Ex. 4' 0" + 
 6' 0'= 10' 0" ^- 2 
 = 5' 0", the mean 
 height of the base 
 or thickness will be 
 5 ' ; 5' 0" x 5' 0" 
 = 25' O'x4' 0" = 
 100 0" + 36' 0" = 
 136'0"+16'0"=152'0"; 152'0" 
 + 6' 0"=25' 4"x 20' 0" = 506' 8" 
 content. 
 
 The same rule applies to the 
 frustum of a cone. 
 Elevation, an upright draught of a 
 
 building, geometrically drawn. 
 Elizabethan Architecture, the style 
 which prevailed in England at the 
 time of Queen Elizabeth, and im- 
 mediately subsequent to the Tudor 
 style of Henry VIII. 
 Ellipse : this curve is one of the conic 
 sections, and next in importance 
 to the circle and the straight line. 
 Ellipsis, an oval figure generated from 
 the section of a cone by a plane 
 cutting both sides of the cone, but 
 not parallel to the base, and meet 
 ing with the base when produced. 
 Elliptic compasses, a term given to 
 any machine for describing ellipses. 
 Elliptograph, an instrument for draw- 
 ing ellipses. 
 Elm, a timber-tree, of European 
 growth, and of which there are five 
 species : mean size, 44 feet long, 
 32 inches diameter : it is not liable 
 to split, and bears the driving 01 
 nails, bolts, etc. : much used in 
 building ; also for the keels of ves- 
 sels, and for wet foundations. 
 Elongation, the act of lengthening. 
 
ELU 
 
 EMBANKMENTS. 
 
 EMB 
 
 Elutriation, the separation of foul sub 
 stances from pure, by pulverization. 
 
 Elutriation, in metallurgy, the sepa- 
 rating the lighter matters from the 
 mixed ores or metals, by means of 
 great quantities of fair water. 
 
 Elvan (in Cornish), a hard close- 
 grained stone, said to be a bastard 
 limestone. 
 
 Embankments, raised mounds or dykes 
 to preserve the proper and useful 
 course of rivers, etc. ; and also for 
 forming a level line of railway. 
 
 Embankments (some} executed on the 
 Continent. On the banks of the 
 Po, two sorts of dykes are used to 
 prevent the river /rom overflowing 
 during the winter, or the flood 
 season. They are called ' in froldi ' 
 when immediately upon the banks 
 of the river, and ' in golene ' when 
 at any considerable distance, as it 
 is sometimes found advisable to 
 allow the river to spread over a 
 large surface of the adjacent valley, 
 either for the purpose of admitting 
 it to deposit the mud in suspension, 
 or to allow it to lose its torrential 
 character. The maintenance of 
 the works of these dykes is con- 
 fided to the Government engineers, 
 who are under the control of a 
 syndicate of the proprietors of the 
 property most liable to be affected 
 by inundations. When the river 
 passes from one State to another, 
 as from Piedmont to Modena, a 
 mixed commission is charged with 
 the joint superintendence. 
 
 The Haarlem lake, besides the 
 very remarkable steam-engines de- 
 scribed by Mr. Dempsey, merits 
 observation for the extensive works 
 executed for the defence of the 
 land, and for the canals reserved 
 for the navigation. The enclosure 
 dyke is 50,000 metres long, or 
 rather more than 31 miles. It has 
 two outfall dykes, which serve for 
 the navigation, 9000 metres, about 
 5 miles; one-half of which is 40 m - 
 (131 ft. 2 in.) wide at the bottom 
 or floor line; the other 43 m - 20 
 (141 ft. 10 in.) 
 
 176 
 
 The ordinary tides are, at the 
 flux, 2 ft. 4 in. above the scale or 
 datum line at Amsterdam ; at the 
 reflux, 2 ft. 8 in. below the same 
 datum : the difference between 
 high and low water is then, on the 
 average, about 5 feet. With vio- 
 lent winds from the N.W. however, 
 the tides rise sometimes G ft. 6 in. 
 above the average. The tides of 
 the Y, near the lake, are + 16 C - (or 
 6^ in.) and 23 C - (or 9 in.), giving 
 a total variation of 1 ft. 3g in. 
 
 The estimated cost of reclaiming 
 the 18,000 hectares was 8 millions 
 of florins, or 667,000 English, 
 nearly, about 13 per acre. Pre- 
 viously to undertaking this colos- 
 sal work, the Zind Plass, of 4600 
 hectares superficial (nearly 11,500 
 acres), had been reclaimed at a cost 
 of 3 millions of florins, or'J50,000; 
 not far from 22 per acre. The 
 heights of the enclosure dyke are 
 + or the datum line or mean 
 level of the sea at Amsterdam. 
 
 Embankment of the flooded part of 
 the Amsterdam and Haarlem Rail- 
 way. The bottom part consists of 
 treble ranges of fascines, tied down 
 by longitudinal poles 1 metre apart 
 from centre to centre, and 25 c. 
 diameter ; two double stakes at 
 each end of the poles, and two ties 
 in the intermediate distances. The 
 interstices of the fascines and the 
 space between the rows are filled in 
 with sand. The upper part, form- 
 ing the encasement for the ballast, 
 is made of three rows of treble fas- 
 cines, well staked, and wattled to- 
 gether. 
 
 A core of sand or clay, faced with 
 step fascines, is made up to low- 
 water mark. Upon this a bed of 
 rushes, fastened down by stakes 
 and wattles, is laid; and the upper 
 portion of the bank is faced with 
 fascines of a regular slope of 1 to 1. 
 
 Embattled, a term applied to any 
 building with a parapet, and having 
 embrasures to resemble a battery. 
 
 Emblema, an emblem, or inlaid orna- 
 ment of divers colours. 
 
EMB 
 
 ENGINEERING. 
 
 ENG 
 
 Emfjolus, in mechanics, a wedge ; an- 
 ciently, among the Greeks, the prow 
 or beak of a vessel, or a body of 
 soldiers in the form of a wedge. 
 
 Embolus, the movable part of a pump 
 or syringe, named likewise the pis- 
 ton or sucker. 
 
 Embossing, forming work in relievo, 
 whether cast or cut with a chisel ; 
 or in modern times, the art of pro- 
 ducing raised figures upon wood or 
 other materials by means of pres- 
 sure, either applied by a sudden 
 blow, as in a stamping press, or in 
 a more gradual manner, as by an 
 ordinary screw or hydraulic press, 
 or by means of revolving cylinders. 
 
 Embrasure, the crenelles or interval 
 between the merlons of a battle- 
 ment. 
 
 Embroidery, a mode of working de- 
 vices on woven substances. 
 
 Emerald green is a new colour of cop- 
 per green upon a terrene base : it is 
 the most vivid of this tribe of 
 colours, being rather opaque, and 
 powerfully reflective of light : it 
 appears to be the most durable 
 pigment of its class. 
 
 Emissarium, a sluice, flood-gate, or 
 channel by which an outlet is 
 formed to carry off stagnant or foul 
 water : according to Pliny, an arti- 
 ficial canal, formed for the draining 
 of stagnant waters. 
 
 Emplecton, a method of constructing 
 walls introduced by the Greeks and 
 copied by the Roman architects, in 
 which the outside surfaces on both 
 sides were formed of ashlar laid in 
 regular courses, and the central 
 space between them filled in with 
 rubble-work, layers of cross stones 
 being placed at intervals in regular 
 courses, and of sufficient size to ex- 
 tend through the entire thickness 
 of the wall, and so act as girders to 
 bind the whole together. 
 
 Emporium, a mart or factory, a large 
 building containing ranges of bond- 
 ing warehouses, in which foreign 
 merchandise brought by sea is de- 
 posited for sale. 
 
 Enamelling, the art of using enamel, 
 
 1 77 
 
 which is divided into trasparent 
 and opaque. The first is- employed 
 for the purpose of ornamenting gold 
 and silver; the second, commonly 
 in the manufacture of watch and 
 clock dials, and of plates for pic- 
 tures, etc. 
 
 Encarpa (Encarpus}, according to 
 Vitruvius, festoons of carved fruit 
 and flowers, employed as decorative 
 ornaments. 
 
 Encaustica, the art of encanslic 
 painting, z'.e. in colours mixed with 
 wax, and afterwards hardened by 
 the action of fire. 
 
 Encaustic painting, a kind of paint- 
 ing in which by heating or burning 
 in, the colours are rendered perma- 
 nent in all their original splendour. 
 
 Enchasing, the art of enriching and 
 beautifying gold, silver, and other 
 metal work, t>y some design or 
 figure represented thereon in basso 
 rilievo. 
 
 Enclosure, a fence, a wall, or hedge, 
 or other means of protection and 
 security surrounding land. 
 
 Endecagon, in geometry, a plane fi- 
 gure of eleven sides and angles. 
 
 End-irons, andirons or dogs, articles 
 of household furniture, in earlier 
 times, used in fire-places to sustain 
 the ends of logs of wood. 
 
 Engineering, Civil. This profession 
 may be said to have originated in 
 England about, the middle of the 
 last century. Before that period, 
 whenever the prospects of great 
 profit induced individuals or bodies 
 to incorporate themselves for the 
 purpose of undertaking CN tensive 
 systems of drainage, or for the 
 supply of water, requiring the as- 
 sistance of an engineer, recourse 
 was generally had to those great 
 masters of hydraulic engineering, 
 the Dutch. True it is that some so- 
 litary exceptions have occasionally 
 been found; men who, like Sir 
 Hugh Myddelton, combined a spe- 
 culative turn of mind with some 
 mechanical knowledge, and to 
 these two qualities added an un- 
 tiring energy of purpose, leading 
 
ENG 
 
 ENGINEERING. 
 
 ENG 
 
 them to persevere in any under-* 
 taking, even under the most dis- 
 couraging circumstances. But 
 these men were rare instances of 
 a peculiar talent, which, though it 
 thus displayed itself occasionally, 
 was far too uncommon a gift to 
 allow the possessors of it to form 
 a class or profession. The case is 
 very different now : a demand for 
 this peculiar talent has been created 
 of late years by the extraordinary 
 development of our system of in- 
 ternal communication, as well as 
 by the application of steam to the 
 purposes of our manufactures ; 
 and employment is now found for 
 hundreds where one was sufficient, 
 not fifty years since, for the whole 
 business of the country. So great 
 indeed has been the demand, that 
 the profession may be said to be 
 divided into two distinct bodies, 
 viz. those who turn their attention 
 to subjects which come more par- 
 ticularly within the scope of the 
 duty of a civil engineer, such as 
 docks, bridges, canals, railroads, 
 etc., and those who devote them- 
 selves altogether to the manufac- 
 ture of machinery. The duties 
 which are involved in the practice 
 of these two branches of the pro- 
 fession, though apparently dissimi- 
 lar in character, are yet founded 
 upon the same general principles ; 
 and the acquirements which are 
 necessary to enable the individual 
 of one class to distinguish himself, 
 or even to practise his profession 
 with a moderate chance of success, 
 will be found equally necessary for 
 those of the other class. 
 
 These acquirements are partly 
 abstract and theoretical, and partly 
 experimental or practical. A civil 
 engineer should, in addition to the 
 knowledge required to fit him as 
 well as others for the active duties 
 of life, have such a knowledge of 
 mathematics as will enable him to 
 investigate as well as to apply the 
 rules laid down by writers on those 
 branches of the mixed sciences to 
 
ENG 
 
 ENGINEER. 
 
 ENG 
 
 sibly be called upon to plan and 
 execute a work himself, and then, 
 by degrees, with industry and ac- 
 tivity, may work his way upwards 
 in a profession where merit alone 
 can lead to distinction. 
 
 The course of the man who de- 
 votes himself to the machinery 
 branch of the profession differs but 
 little, up to a certain point, from 
 that just described : his theoretical 
 acquirements should be the same, 
 but the practical part of his edu- 
 cation will commence at the bench, 
 where he will learn the use of all 
 the tools and machinery by working 
 at them with his own hands : he 
 will then be placed in the drawing 
 room, and go through much the 
 same routine of instruction as be- 
 fore described, and will by degrees 
 work his way up to the position 
 of foreman; then, distinguishing 
 himself by a power of applying 
 general principles to particular 
 cases, he will show himself capable 
 of assuming the direction of an 
 establishment for the manufacture 
 of machinery. 
 
 Engineer, Steam-boat. A steam-boat 
 engineer is a person employed for 
 the purpose of keeping the engine 
 or engines of a steam-vessel in as 
 efficient a state as possible, and to 
 superintend their working. 
 
 He must set the engines to work, 
 regulate their speed, and stop them, 
 as may be required. His duties 
 while the engines are at work are 
 various. He must take care that 
 every moving part is properly lu- 
 bricated ; that no steam is allowed 
 to pass through valves or joints that 
 ought to be steam-tight ; that no 
 air is permitted to enter in any of 
 the parts of the engine where it 
 is essential that a vacuum should 
 be kept up ; and that none of the 
 bolts, or pins, or keys, work loose 
 by the vibration, and shift their 
 position, or come out of their 
 places. He must also take care 
 that none of the working parts be- 
 come overheated by any undue 
 
 170 
 
 amount of friction, arising from 
 any want of proper lubrication, 
 any excessive tightness, or any 
 other disturbing cause ; and if they 
 should become overheated, he 
 must take prompt and energetic 
 measures to remedy the evil, and 
 prevent any serious consequences 
 arising therefrom. He must from 
 time to time carefully observe the 
 effect produced by the gradual wear 
 of the working parts, so that if the 
 truth or accuracy of any of these 
 seems to be materially affected, he 
 may take steps to rectify the defects 
 when lying up in harbour. He must 
 also be careful to observe if the 
 frame of the engine ever begins to 
 move or work in any way, and en- 
 deavour to discover the cause, in 
 order that it may be remedied when 
 the engines are at rest. One of the 
 most important of his duties is to 
 take care that the engines are kept 
 clean, and any grit or dirt prevented 
 from getting into the bearings or 
 moving parts : he must wipe away 
 all oil and grease most carefully 
 and completely as soon as they have 
 passed through the bearings, and 
 prevent them from running down 
 the rods or remaining about the 
 engine. 
 
 The boiler requires his unremit- 
 ting and particular attention, in 
 order that the proper supply of 
 steam, neither too much nor too 
 little, may be generated for the en- 
 gine. To ensure this, the manage- 
 ment of the fires must be duly 
 attended to, both in the supply of 
 coal in the proper quantities at. the 
 proper intervals, and in the perio- 
 dical clearing of the fires from the 
 earthy matters of the coal, which 
 may have become vitrified in the 
 furnace, and formed what are call- 
 ed clinkers. By due attention to 
 the former, the smoke in all well- 
 proportioned boilers may be very 
 greatly abated ; and, by due at- 
 tention to both, the consumption 
 of fuel (when the engines are pre- 
 vented by a strong head-wind, or 
 
ENG 
 
 ENGINEER. 
 
 ENG 
 
 by the deep immersion of the* 
 paddle-wheels on the commence- 
 ment of a long voyage, from making 
 the proper number of strokes, and 
 thus using the proper amount of 
 steam) may be reduced in an equal 
 or greater degree than has taken 
 place in the consumption of steam. 
 The due and constant supply of 
 water to the boiler, to compensate 
 for the constant evaporation of the 
 water in the formation of the steam, 
 must be assiduously attended to. 
 Another of the most important of 
 the duties of a steam-boat engineer, 
 during the time that the engines 
 are at work on a voyage at sea, 
 is to attend to the degree to which 
 the water in the boilers may be- 
 come saturated with salt by thecon- 
 tinued evaporation which is going 
 on, and to take care that this satu- 
 ration is not allowed to be carried 
 to such an extent as that a deposi- 
 tion of the salt and other matters 
 contained in sea- water should take 
 place. After the boilers have been 
 in operation for three or four hours 
 in salt water, so that the water in 
 them has become brine, he ought to 
 test the strength of it, that is, he 
 ought to ascertain the degree of sa- 
 turation to which it has reached, 
 and continue this examination pe- 
 riodically, whether the engines are 
 fitted with an apparatus for the con- 
 tinuous discharge of a portion of 
 the brine, to be exchanged for a 
 portion of sea-water, or whether 
 this system of exchange is left en- 
 tirely at his discretion, to be at- 
 tended to by means of the common 
 blow-off cocks. The best test is the 
 common hydrometer, though the 
 thermometer has hitherto been 
 more commonly applied to this pur- 
 pose, as the brine is considered to 
 be of a proper strength when it boils 
 under atmospheric pressure at a 
 temperature 2 higher than that at 
 which the common sea-water will 
 boil at the same time, under the 
 same circumstances. 
 
 Before coming into port, it may 
 
 occasionally be advantageous to 
 take indicator diagrams, to see 
 whether the action of the valves 
 continues to be correct. 
 
 The duties of a steam-boat en- 
 gineer, on arriving in port after a 
 long voyage, are also various, and 
 equally important with those he has 
 to perform when out at sea. Im- 
 mediately on coming to anchor, it 
 is a good practice to test the tight- 
 ness of the steam-valves and pis- 
 tons, by putting them in such a 
 position that it can be seen if they 
 allow any steam to pass when it 
 ought not to do so. It' any im- 
 perfections in these the most vital 
 parts of the engines are discovered, 
 he must draw out the valves, or 
 lift the cylinder covers, to get at 
 the pistons, and rectify the defects 
 in the best manner that he can with 
 the means within his power. He 
 should also occasionally examine 
 all the interior parts of the engines, 
 and rectify any incipient defects. 
 He must now also rectify any want 
 of truth in the parallel motion or 
 in any of the shafts or working 
 parts caused by wear, and tighten 
 or make good any of the fastenings 
 of the frame if he has found them 
 to be loose, and put to rights any 
 other such defects. Any parts sub- 
 ject to corrosion should be carefully 
 examined, cleaned, and dried, and 
 painted if need be. The water 
 should be blown off out of the 
 boilers as completely as possible, 
 and all ashes and soot thoroughly 
 cleaned out of the furnaces and 
 flues as soon as possible. The fur- 
 naces and flues must then be tho- 
 roughly examined, and the slight- 
 est leak or defect that can be 
 discovered made good ; as it is 
 especially important in a boiler to 
 stop these defects at the first, as 
 otherwise they spread very rapidly. 
 No pains should be spared to dis- 
 cover any suspected leak of steam 
 on the top of the boiler, as nothing 
 te*nds more to corrode and destroy 
 a boiler than this. Inside the boil- 
 
ENG 
 
 ENGLISH SCHOOL OF PAINTING. 
 
 ENG 
 
 ers, any scale that may have been 
 deposited from the brine having 
 been allowed to become too strong 
 must be removed, and the whole 
 thoroughly cleaned out from every 
 part of the boiler, from below as 
 well as from the tops and sides of 
 the furnaces and flues. The take- 
 up, the inside of the steam-chests, 
 and of the roofs of the boilers, 
 which are the parts most subject to 
 corrosion from the interior, should 
 he very carefully examined, and 
 after being duly scraped andcleaned 
 and dried, they should he well 
 painted with two or three coats of 
 red lead, or done over with some 
 other preservative. 
 
 The paddle-wheels should also 
 be thoroughly examined, and any 
 broken floats or hook-bolts replaced 
 by new ones. The whole of the 
 ironwork should be thoroughly 
 scraped and cleaned, and, when 
 dry, painted with three coats of 
 red lead, or done over with black 
 varnish, once every four months 
 at least. "When in harbour, espe- 
 cially if lying in a stream or tide- 
 way, the wheels ought to be turned 
 round every three or four days, to 
 change the parts exposed to the 
 action of the water, and thus pre- 
 vent corrosion. The various kinds 
 of the screw now in use should be 
 well studied, and all circumstances 
 connected* with its operations 
 should be closely watched for every 
 incident or change should be con- 
 sidered as a new experiment. 
 
 He must now also get his supply 
 of stores made good, so as to be 
 ready for another voyage. 
 
 To qualify an engineer to per- 
 form these duties, he should be 
 trained as a mechanic, and be a fair 
 workman in iron, brass, and wood. 
 He should be able to work rot only 
 at the lathe or vice, but also at a 
 smith's forge. His education should 
 be such as to make him able to keep 
 accounts, and make notes in his log 
 of all that occurs in the engine- 
 room. He should have sufficient 
 
 knowledge of mechanical drawing 
 to enable him, in the event of any 
 important part of the engines being 
 broken when at a distance from any 
 manufactory, to make such a draw- 
 ing of it as would enable a manu- 
 facturer to replace it. He should 
 have some knowledge of the first 
 principles of mechanics, a general 
 knowledge of the leading principles 
 of hydrostatics, hydraulics, and 
 pneumatics, without which he can- 
 not fully understand many of the 
 principles carried on in the engine, 
 and on which its power depends. 
 Some knowledge of heat, of the 
 theory of combustion, of ebullition, 
 and of evaporation, may also be 
 reckoned as almost indispensable : 
 to which should be added, if pos- 
 sible, an acquaintance with the sub- 
 ject of steam, especially as regards 
 its temperature, pressure, and latent 
 heat. 
 
 Engineer, Mechanical, one who is effi- 
 cient in the invention, contrivance, 
 putting together, and the adjust- 
 ment of all kinds of machinery ; 
 who is acquainted with the strength 
 and quality of the material used, 
 and who also possesses a thorough 
 knowledge of the power of steam 
 and the engine in all its modifica- 
 tions, and the uses for which this 
 motive power is applied : he should 
 also be duly acquainted with mill- 
 work of the several kinds, whether 
 impelled by steam, water, or wind. 
 
 English School of Painting. This 
 school, which is but of recent date, 
 is connected with the Royal Acade- 
 my in London, instituted in 1766 ; 
 and although as a school it did not 
 exist before that period, yet since 
 the revival of the arts, and the con- 
 sequent encouragement given to 
 them by the sovereigns of Europe, 
 England has possessed portrait- 
 painters of no inconsiderable abi- 
 lity ; and it is probably owing to 
 the remarkable partiality of the na- 
 tion for this branch of the art, that 
 historical painting has been, until 
 recently, comparatively neglected. 
 
ENG 
 
 ENTABLATURE. 
 
 EPI 
 
 Latterly, however, painters of the 
 highest eminence in this superior 
 hranch of the art havedistinguished 
 themselves, and given earnest of 
 the rise of a school that may, ere 
 long, surpass others of the pre- 
 sent age. 
 
 English Varnish. When mastic var- 
 nish is mixed with drying-oil which 
 holds litharge in solution, the mix- 
 ture soon assumes the appearance 
 of a firm jelly ; which is strong in 
 proportion as a greater quantity of 
 litharge, and a stronger varnish, 
 have been used. This substance 
 holds its place on the palette. This 
 mixture is particularly useful in 
 glazing, for it flows freely under 
 the brush. Instead of using brown 
 drying-oil, it is preferable to use 
 that prepared without fire. 
 
 Entablature, those members of a por- 
 tico which were constructed upon 
 the columns, consisting of theepi- 
 stylium, zophorus, and corona. Vi- 
 truvius uses the words ornament a 
 columnarum to signify these mem- 
 bers ; and sometimes he includes 
 the three several parts in the term 
 epistylia. 
 
 Entablature, the superstructure that 
 lies horizontally upon the columns 
 in the several orders or styles of 
 architecture. It is divided into 
 architrave, the part immediately 
 above the column ; frieze, the cen- 
 tral space ; and cornice, the upper 
 projecting mouldings. Each of the 
 orders has its appropriate entabla- 
 ture, of which both the general 
 height and the subdivisions are re- 
 gulated by a scale of proportion 
 derived from the diameter of the 
 column. 
 
 The entablature, though archi- 
 tects frequently vary from the pro- 
 portions here specified, may, as a 
 general rule, be set up one-fourth 
 the height of the column. The to- 
 tal height thereof thus obtained is 
 in all the orders, except the Doric, 
 divided into ten parts, three of 
 which are given to the architrave, 
 three to the frieze, and four to the 
 
 cornice. But in the Doric order 
 the whole height should be divided 
 into eight parts, and two given to 
 the architrave, three to the frieze, 
 and three to the cornice. The 
 mouldings which form the detail 
 of these leading features are best 
 learned by reference to representa- 
 tions of the orders at large. Pal- 
 ladio and Vignola, the restorers of 
 genuine architecture, are the au- 
 thors whose works may be con- 
 sulted with greatest advantage by 
 those who desire to make any ad- 
 vance in the science, and most par- 
 ticularly by those who wish to ob- 
 tain further knowledge on the use 
 and abuse of its details. 
 
 Entail, a term used in the middle 
 ages to signify elaborated sculp- 
 tured ornaments and carvings. 
 
 Entasis, the swell of the shaft or co- 
 lumns of either of the orders of ar- 
 chitecture. 
 
 Enterclose, a passage between two 
 rooms in a house, or that leading 
 from the door to the hall. 
 
 Entresol, in architecture, a floor be- 
 tween two other floors. The en- 
 tresol consists of a low apartment 
 usually placed above the first floor : 
 in London, frequently between the 
 ground floor and the first floor. 
 
 Ephebeum, an apartment in the pa- 
 laestra appropriated to wrestling 
 and other athletic exercises. 
 
 Epicycle, a little circle whose cen- 
 tre is in the circumference of a 
 greater. 
 
 Epicycloid, a curve generated by the 
 revolution of the periphery of a 
 circle along the convex or concave 
 part of another circle. 
 
 Epicycloidal wheel, a wheel for con- 
 verting circular into alternate mo- 
 tion, or alternate into circular. 
 
 Episcenium, a division of the scene of 
 a Greek theatre : it sometimes con- 
 sisted of three divisions made by 
 ranges of columns one above the 
 other : the lower was termed scena, 
 and the others episcenia. 
 
 Epistomium, the cock or spout of a 
 water-pipe, or of any vessel contain- 
 
EPI 
 
 ERA. 
 
 EVA 
 
 ing liquids to be drawn off in small 
 quantities when required. 
 
 Epistylium, the lower of three divi- 
 sions of an entablature or super- 
 structure upon the columns of a 
 portico, formed by pieces extend- 
 ing from centre to centre of two 
 columns. 
 
 Epistylium, the architrave or hori- 
 zontal course resting immediately 
 upon columns. Epistylar arcua- 
 tion is the system in which co- 
 lumns support arches instead of 
 horizontal architraves and entab- 
 latures. 
 
 Epitithidas, a term applied by some 
 writers, by way of distinction, to 
 the cymatium on the sloping or 
 raking cornices of a pediment, 
 which superimposed moulding (as 
 its name implies) was frequently 
 largely developed, and enriched 
 with an ornamental pattern. 
 
 Epitithides, the upper members of the 
 corona surmounting the fastigium 
 of a temple, which was also con- 
 tinued along the flanks. 
 
 Epotides, in naval architecture, two 
 thick blocks of wood, one on each 
 side the prow of a galley, for ward- 
 ing off the blows of the rostra of 
 the enemy's vessel. 
 
 Equation, an equal division : in alge- 
 bra, a mutual comparing of things 
 of different denominations : in as- 
 tronomy, the difference between 
 the apparent and mean motion of 
 the sun. 
 
 Equilateral, having all sides equal. 
 
 Equilibrium, equipoise, equality of 
 weight. 
 
 Equilibrium valve, the valve in the 
 steam passage of a Cornish engine 
 for opening the communication be- 
 tween the top and bottom of the 
 cylinder, to render the pressure 
 equal on both sides of the piston. 
 
 Era. The year 5611 of the Jewish 
 era commenced September 7, 1850 ; 
 Ramadan, the month of abstinence 
 observed by the Turks, July 11, 
 1850 ; the year 1267 of the Mo- 
 hammedan era, Nov. 6, 1850; and 
 the Christian era, 1849 since the 
 
 birth of Jesus Christ, for 1850 
 years, on the 1st of January, 
 1850. 
 
 Erasement (applied to buildings and 
 cities), entire destruction and de- 
 molition. 
 
 Ergastulum, a sort of prison or house 
 of correction contiguous to the 
 farms and country villas of the 
 Romans. 
 
 Ergata, a capstan or windlass. 
 
 Erisma, an arch-buttress, shore-post, 
 or prop, to hold up buildings. 
 
 Euripus, an arm of the sea with land 
 on both sides ; a canal, a pool, or 
 stand of water; ditch, a trench 
 or moat about a place ; a water-pipe 
 of the smaller size, so made that 
 the water therein may mount aloft : 
 also an inlet or small creek. 
 
 Escape, the scape of a column in ar- 
 chitecture. 
 
 Escutcheon, a shield charged with 
 armorial hearings. 
 
 Etching, a branch of engraving in 
 which the lines are drawn by a 
 stylus or etching-needle, on copper, 
 steel, or stone, prepared by a che- 
 mical process. 
 
 Eudiometer, an instrument used to 
 ascertain the purity of air, or rather 
 the quantity of oxygen contained 
 in any given bulk of elastic fluid. 
 
 Eurythmy, in architecture, the exact 
 proportion between all parts of a 
 building. 
 
 Eustyle,\\\ai intercolumniation which, 
 as its name would import, the an- 
 cients considered the most elegant, 
 viz. two diameters and a quarter of 
 the column. Vitruvius says, this 
 manner of arranging columns ex- 
 ceeds all others in strength, conve- 
 nience, and beauty. 
 
 Evangelists, The. In the Table of 
 Symbols of the early ages, by the 
 four Mystic Animals, Rev. iv. 7 : 
 The Angel being assigned to St. 
 Matthew, the Lion to St. Mark, 
 the Ox to St. Luke, and the Eagle 
 to St. John ; and the four rivers 
 issuing from the Mount of Paradise 
 to enter the earth, Gen. ii. 10. 
 
 Evaporation, the transformation of a 
 
EVO 
 
 EXPANSIVE STEAM. 
 
 EXP 
 
 liquid into a gaseous state by th 
 action of heat. 
 
 Evolute, a particular species of curve. 
 
 Evolution, in geometry : the equable 
 evolution of the periphery of a cir- 
 cle, or any other curve, is such a 
 gradual approach of the circum- 
 ference to rectitude as that all the 
 parts meet together, and equally 
 evolve or unbend. 
 
 Ewry, an office of household service, 
 where the ewers, etc., were for- 
 merly kept. 
 
 Examen, the tongue on the beam of 
 a balance, rising perpendicularly 
 from the beam, and moving in an 
 eye affixed to the same, by which 
 it serves to point out the equality 
 or inequality of weight between 
 the objects in the scale. 
 
 Excalefaction, heating or warm- 
 ing. 
 
 Exedra, an assembly-room or hall of 
 conversation ; according to Vitru- 
 vius, a large and handsome apart- 
 ment; also a by-place, or jutty. 
 
 Exedra, or Exhedra, the portico of 
 the Grecian palaestra, in which dis- 
 putations of the learned were held : 
 so called from its containing a 
 number of seats, generally open, 
 like the pastas or vestibule of a 
 Greek house. 
 
 Exemplar, a pattern, plan, or model ; 
 resemblance. 
 
 Exhaust-port, the exit passage for the 
 steam from a cylinder. 
 
 Exhaust-valve, the valve in the educ- 
 tion passage of the steam cylinder 
 of a Cornish engine, placed between 
 the cylinder and air-pump, and 
 worked by the tappet motion, so as 
 to open shortly after the equili- 
 brium valve, and admit the steam 
 to the condenser. 
 
 Existence, being, entity, subsistence, 
 reality, actuality, positiveness, ab- 
 soluteness, fact. Verb : to be, to 
 exist, have being, subsist, live, 
 breathe. 
 
 Expansion-joint, a stuffing-box joint 
 connecting the steam-pipes, so as 
 to allow one of them to slide 
 within the enlarged end of the 
 
 18/L 
 
 other when the length increases 
 by expansion. 
 
 Expansion-valve, an auxiliary valve 
 placed between the slide-valve and 
 the steam cylinder : it is worked by 
 a cam or other contrivance, so as 
 to cut off the steam at a given pe- 
 riod, and cause the remainder of 
 the stroke to be performed by ex- 
 pansion. 
 
 Expansive steam. The expansive pro- 
 perties of steam are now well un- 
 derstood, and extensively applied 
 to practice in manufacturing dis- 
 tricts. In Cornwall, and in some 
 other parts of the kingdom, the ap- 
 plication is attended with highly 
 beneficial results. But it should 
 be stated that this system can be 
 introduced with much greater ad- 
 vantage in engines that are em- 
 ployed in raising water, than in 
 those which are entirely devoted 
 to manufacturing purposes. In 
 these last, the power is opposed to 
 a continually varying resistance ; 
 while, in the former, the resistance 
 is commonly the same, or of equal 
 intensity. 
 
 To pumping engines, the adop- 
 tion of the expansive system to an 
 almost unlimited extent is recom- 
 mended, even to the exclusion of 
 any further ingress of steam to the 
 cylinder after the piston has passed 
 through but one-eighth or one- 
 ninth of its stroke. 
 
 Expansive steam may be thus 
 explained : If we allow steam to 
 flow into the cylinder of a steam- 
 engine until the piston be de- 
 pressed to one-half of the stroke, 
 and then prevent the admission of 
 any further quantity, the piston 
 will, if the engine be properly 
 weighted, continue its motion to 
 the bottom. The pressure of the 
 steam, so long as the supply is 
 continued from the boiler, will be 
 equal, it is presumed, to ten pounds 
 upon the inch. With this force it 
 will act upon the piston until it 
 completes one-half of the stroke : 
 the further supply of steam will 
 
EXP 
 
 EXPRESSION. 
 
 EXT 
 
 then he excluded, arid that wuich 
 is in the cylinder will expand as the 
 piston descends, so that when the 
 stroke is completed it will occupy 
 the entire capacity. The pressure 
 of the steam will then be halt' of 
 its former amount, or five pounds 
 upon the inch. 
 
 During the descent of the pis- 
 ton, the pressure of the steam does 
 not suddenly decrease from ten 
 pounds to five; but it gradually 
 declines, through the successive 
 intervals, until at the final point it 
 yields that force. It is by this gra- 
 dual expansion and diminution of 
 pressure that the superior action is 
 produced. 
 
 Experiments on Brass. Dr. Young 
 made some experiments on brass, 
 from which he calculated the 
 height of the modulus of elasticity 
 of brass plate to be 4,940,000 feet, 
 or 18, 000,000 Its. for its weight, to 
 a base of 1 square inch. For wire 
 of inferior brass he found the 
 height to be 4,700,000 feet. 
 
 As cast brass had not been sub- 
 mitted to experiment, a cast bar 
 of good brass was procured, with 
 which the following experiment was 
 made : 
 
 The bar was filed true and regu- 
 lar: its depth was 0'45 inch, and 
 breadth 0'7 inch ; the distance be- 
 tween the supports was 12 inches, 
 and the scale suspended from the 
 middle. 
 
 Iba. inch. 
 
 12 bent the bar 01 
 
 23 0-02 
 
 38 
 52 
 
 65 
 110 
 
 163 
 
 f The bar was 
 Q.QO | relieved seve- 
 
 | it took no per- 
 (^ceptible set. 
 
 n A c 
 } ' 05 
 
 f Relieved, the 
 \setwas-01. 
 . 0-18 
 
 |" slipped between the 
 J supports, bent more 
 ] than 2 inches, but did 
 ! not break. 
 
 Hence 52 Ibs. seems to be about 
 the limit which could not be 
 much exceeded without permanent 
 change of structure. It is equiva- 
 lent to a strain of 6700 Ibs. upon a 
 square inch, and the corresponding 
 extension is y^g- of its length. Ab- 
 solute cohesion above 2 1,000 Ibs. 
 per square inch. The modulus of 
 elasticity according to this experi- 
 ment is '8,930, 000 ibs. for a base of 
 an inch square. The specific gra- 
 vity of the brass is 8 37, whence 
 we have 2,460,000 feet for the 
 height of the modulus. 
 
 Expression principally consists in re- 
 presenting the human body and all 
 its parts in the action suitable to 
 it ; in exhibiting in the face the se- 
 veral passions proper to the figures, 
 and marking the motions they im- 
 press on the other external parts. 
 
 Expression, in painting, con- 
 sists in the representation of those 
 attitudes of the body, and varia- 
 tions of the countenance which 
 always accompany and indicate 
 the immediate influence of the pas- 
 sions on the mind. 
 
 Expression of colour. Every pas 
 sion and affection of the mind has 
 its appropriate tint; and colour- 
 ing, if properly adapted, lends its 
 aid, with powerful effect, in the 
 just discrimination and forcible ex- 
 pression of them : it heightens joy, 
 warms love, inflames anger, deep- 
 ens sadness, and adds coldness to 
 the cheek of death itself. 
 
 External thermometer (the) should 
 be a mercurial one, well exhausted 
 of air, and the graduated scale di- 
 vided to tenths of a degree, or into 
 quarters of a degree, or with whole 
 divisions large enough to be di- 
 vided into as many parts by the 
 eye. Choose a locality for the 
 instrument, where it will be well 
 exposed to the ambient air, apart 
 from the reflection of sunbeams, 
 etc., and where it may be dis- 
 tinctly read off without inconve- 
 nience. It should lie read off as 
 quickly as possible. For uniformity 
 
 185 
 
EXT 
 
 FAHRENHEIT. 
 
 FAN 
 
 of system, it should be read off #t 
 stated periods, the same time at 
 which the barometer, etc., are 
 noted, and carefully watched in 
 the interim, to see whenever any 
 remarkable change occurs ; before 
 and after storms, during eclipses of 
 the sun and moon, or the passage 
 of dense clouds of vapour, etc. 
 Extract of gamboge is the colouring 
 matter of gamboge separated from 
 its greenish gum and impurities by 
 solution in alcohol and precipita- 
 tion, by which means it acquires a 
 powdery texture, rendering it mis- 
 cible in oil, etc., and capable of 
 
 FABER, a name given by the Romans 
 to any artisan or mechanic who 
 worked in hard materials. 
 
 Fabrica, according to the Romans, 
 the workshop of any mechanic. 
 
 Fabrication, the art of building, con- 
 struction. 
 
 Fabrillia, according to Horace, me- 
 chanics' tools. 
 
 Facade, the face or front of any con- 
 siderable building to a street, court, 
 garden, or other place. 
 
 Face-piece, in ship-building, a piece 
 wrought on the fore-part of the 
 knee of the head, to assist the con- 
 version of the main-piece, and to 
 shorten the upper bolts of the 
 knee of the head. 
 
 Fagg (sea term) the ends of those 
 strands which do not go through 
 the tops, when a cable or rope is 
 closed. 
 
 Fagot of Steel, 120 Ibs. weight. 
 
 Faithful (the), (on the table of sym- 
 bols of the early ages), represented 
 by sheep, John x. 14 ; by fish, Matt, 
 xii. 47 ; by doves eating grapes or 
 ears of corn ; by stags, Psalm xlii. 
 2 ; by date-trees or cedar-trees, 
 Isaiah i. 13 ; Jerem. xvii. 8 ; by 
 little children. 
 
 Fahrenheit, a native of Dantzic, was 
 born in 1686 : he invented the scale 
 called after his name : he also im- 
 proved the thermometer by sub- 
 
 186 
 
 use in glazing. It is at the same 
 time improved in colour, and re- 
 tains its original property of work- 
 ing well in water and gum. 
 
 Extrados, the exterior curve of an 
 arch, measured on the top of the 
 voussoirs, as opposed to the soffit 
 or intrados. 
 
 Eye, a name given to certain circular 
 parts and apertures in architecture, 
 but more especially to the central 
 circle of the Ionic volute ; to the 
 circular or oval window in a pedi- 
 ment ; to a small skylight in a 
 roof, or the aperture at the sum- 
 mit of a cupola. 
 
 stituting mercury instead of spirits 
 of wine, and formed a new scale 
 for the instrument, founded on ac- 
 curate experiments, fixing the freez- 
 ing point of water at 32, and that 
 ot boiling at 212. 
 
 Faldvtool, or folding stool, a portable 
 seat made to fold up in the manner 
 of a camp-stool : it was made either 
 of metal or wood, and sometimes 
 covered with rich silk. 
 
 False red is a second red, Avhich 
 is sometimes put under the first, 
 to make it deeper. 
 
 False stem in a ship, when the stem 
 being too flat, another is fastened 
 to it. 
 
 False-roof, the space between the 
 ceiling and the roof above it, whe- 
 ther the ceiling is of plaster or a 
 stone vault, as at King's College 
 chapel, Cambridge, and St. Jacques 
 church, Liege. 
 
 Fan-tracery vaulting : this was used 
 in late Perpendicular work, in 
 which all the ribs that rise from 
 the springing of the vault have the 
 same curve, and diverge equally in 
 every direction, producing an ef- 
 fect like the bones of a fan : very 
 fine examples of it exist in Henry 
 the Vllth's chapel, Westminster, 
 St. George's chapel, Windsor, and 
 in King's College chapel, Cam- 
 bridge. 
 
FAN 
 
 FARM. 
 
 FAU 
 
 Fanal, a pharos or lighthouse, or the 
 lantern placed in it. 
 
 Fang, in mining, a niche cut in the 
 side of an adit, or shaft, to serve 
 as an air-course : sometimes a main 
 of wood-pipes is called afanging. 
 
 Fanners, vanes or flat discs revolving 
 round a centre, so as to produce a 
 current of air; generally used in- 
 stead of bellows for forges. 
 
 Fanum, a Roman temple or fane, usu- 
 ally consecrated to some deity. 
 
 Farm. Vitruvius says, " The mag- 
 nitude of the buildings must de- 
 pend wholly upon the quantity of 
 land attached to them, and upon 
 its produce. The number of courts 
 and their dimensions must be pro- 
 portioned to the herds of cattle 
 and the quantity of oxen employed. 
 The kitchen should be situated in 
 the warmest part of the court, and 
 the stable for the oxen contiguous 
 to it : the stalls should be made 
 to face the hearth and the east ; 
 because when oxen are constantly 
 exposed to light and heat, they be- 
 come smooth-coated. No hus- 
 bandman, however ignorant, will 
 suffer cattle to face any other 
 quarter of the heavens than the 
 east. The width of the stables 
 ought not to be less than ten nor 
 more than fifteen feet, their length 
 proportioned to the number of 
 yokes, each of which should oc- 
 cupy an extent of seventeen feet. 
 The scalding-rooms should adjoin 
 the kitchen, in order that the ope- 
 ration of cleaning the utensils may 
 be performed upon the spot. The 
 courts for sheep, etc., should be 
 so spacious as to allow not less 
 than four and a half nor more 
 than six feet to each animal. The 
 granaries should be aboveground, 
 and made to front, either the north 
 or the north-east, in order that the 
 grain may not be liable to fer- 
 ment ; but, on the contrary, by ex- 
 posure to a cold atmosphere, may 
 be preserved a long time : all other 
 aspects encourage the propagation 
 of worms and insects destructive 
 
 187 
 
 to grain. The stables should be 
 built in the warmest part of the 
 villa most distant from the hearth ; 
 because when horses are stalled 
 near fire they become rough-coated. 
 It is likewise expedient to have 
 stalls for oxen at a distance from 
 the kitchen, in the open air : these 
 should be placed so as to front the 
 east, because if they are led there 
 to be fed in winter when the sky is 
 unclouded they will improve in 
 appearance. The barns, the hay- 
 yards, the corn-chambers, and the 
 mills ought to be without the walls; 
 so that the farm may be less liable 
 to accidents from fire." 
 
 Farm, in Cornish mining, that part 
 of the lord's fee which is taken for 
 liberty to work in tin-mines only 
 that are bounded, which is gene- 
 rally one-fifteenth of the whole. 
 
 Fascia, a flat architectural member in 
 an entablature or elsewhere; a 
 band or broad fillet. The architrave 
 in the more elegant orders of archi- 
 tecture is divided into three bands, 
 which are called fasciae : the lower 
 is called the first fascia, the middle 
 one the second, and the upper one 
 the third fascia. 
 
 Fasciae, the bands of which the epi- 
 stylium of the Ionic and Corinthian 
 orders are composed. The ante- 
 pagments of Ionic doorways were 
 generally divided into three fasciae 
 or corsae. Fasciae were also bands 
 which the Romans were accus- 
 tomed to bind round the legs. 
 
 Fast and loose pulleys, two pulleys 
 placed side by side on a shaft 
 which is driven from another shaft 
 by a band : when it is required to 
 stop the shaft, the band is trans- 
 ferred to the loose pulley. 
 
 Fastigium, the pediment of a portico ; 
 so called because it followed the 
 form of the roof, which was made 
 like a triangle, the sides being 
 equally inclined, to carry off the 
 water. In architecture, the sum- 
 mit, apex, or ridge of a house or 
 pediment. 
 
 Faux, according to Vitruvius, a nar- 
 
FAY 
 
 FENESTRATION. 
 
 FEN 
 
 row passage which formed a couj- 
 munication between the two prin- 
 cipal divisions of a Roman house, 
 the atrium and peristylium. 
 
 Fay, in ship-building, to join two 
 pieces of timber close together. 
 
 Feathering or foliation, an arrange- 
 ment of small arcs or foils sepa- 
 rated by projecting points or cusps, 
 used as ornaments in the mould- 
 ings of arches, etc., in Gothic archi- 
 tecture. 
 
 Feed-head, a cistern containing water 
 and communicating with the boiler 
 of a steam-engine by a pipe, to 
 supply the boiler by the gravity of 
 the water, the height being made 
 sufficient to overcome the pressure 
 within the boiler. 
 
 Feed-pipe, the pipe leading from the 
 feed-pump, or from an elevated 
 cistern, to the bottom of the 
 boiler of a locomotive engine. 
 
 Feed-pipe cocks, those used to regulate 
 the supply of water to the boiler of 
 a locomotive engine, and the handle 
 of which is placed conveniently to 
 open and shut at pleasure. 
 
 Feed-pipe strainer, or strum, a perfo- 
 rated half-spherical piece of sheet- 
 iron, after the manner of the rose 
 end of a watering-pot: it is placed 
 over the open end of the feed-pipe 
 in the locomotive tender tank, to 
 protect it. 
 
 Feed-pipes, the copper pipes reaching 
 from the clack-box to the pump 
 and from the pump to the tender, 
 to convey water to the boiler of a 
 locomotive engine. 
 
 Feed-pump, a forcing-pump, worked 
 by the steam-engine, for supplying 
 the boiler with water. 
 
 Feed-pump plunger, the solid piston, 
 or enlarged end of the pump-rod, 
 fitting the stuffing-box of the pump 
 of a steam-engine. 
 
 Felling timber, the act of cutting 
 down a full-grown tree, which 
 doubtlessly should be done late in 
 the autumn, when less moisture 
 exists in all trees, and which ren- 
 ders the timber less liable to dry- 
 rot. 
 
 188 
 
 Felspar, a mineral of foliated structure. 
 
 Felucca, in navigation, a little vessel 
 used in the Mediterranean, capable 
 of going either stem or stern fore- 
 most ; also a small open boat, row- 
 ed with six oars. 
 
 Femerell, a lantern, louvre, or covering 
 placed on the roof of a kitchen, 
 hall, etc., for the purpose of venti- 
 lation or the escape of smoke. 
 
 Femur, in architecture, the long, flat 
 projecting face between each chan- 
 nel of a triglyph ; the thigh, or a 
 covering for the thigh. 
 
 Fender-piles, those driven to protect 
 work either on land or in water. 
 
 Fenders, to vessels or ships, are 
 pieces of old ropes, or wooden 
 billets, hung over the side to pre- 
 vent injury from collision with 
 other ships. 
 
 Fender-bolls are iron pins for the 
 protection of the sides of ships. 
 
 Fenestella, the niche at the side of 
 an altar containing the piscina, a 
 vessel JT holding water to wash 
 the hands of the officiating priest ; 
 also a little window. 
 
 Fenestra, a window, an entrance. 
 
 Fenestrai : window-blinds, or case- 
 ments closed with paper or cloth, 
 instead of glass, are so termed. 
 
 Fenestration, termed by the Germans 
 Fenster-architektur, is, in contra- 
 distinction to columniation, the 
 system of construction and mode 
 of design marked by windows. Fe- 
 nestration and columniation are so 
 far antagonistic and irreconcilable, 
 that fenestration either interferes 
 with the effect aimed at by colum- 
 niation with insulated columns, as 
 in a portico or colonnade, or re- 
 duces it, as is the case with an 
 engaged order, to something quite 
 secondary and merely decorative. 
 Astylar and fenestrated ought, 
 therefore, to be merely convertible 
 terms ; but as they are not, that of 
 columnar fenestrated has been in- 
 vented, to denote that mode of 
 composition which unites fenestra- 
 tion with the semblance, at least, 
 of the other. Employed as a col- 
 
PER 
 
 FINLAYSON'S TABLES. 
 
 FIN 
 
 lective term, fenestration serves to 
 express the character of a building 
 or design with regard to the win- 
 dows generally: thus it is said, the 
 fenestration is excellent, or the 
 contrary, ornate or meagre, well 
 arranged or too crowded, which 
 last circumstance is a very common 
 fault, and is destructive both of 
 grandeur and of repose. 
 
 Feretory, a bier, or coffin ; a tomb, 
 or shrine, 
 
 Ferrari (Gaudenzio), called by Vasari 
 Gaudenzio Milanese, was ranked 
 among the seven greatest painters 
 in the world. 
 
 Ferrule, a metal ring fixed on the 
 handle of a tool to prevent the 
 wood from splitting. 
 
 Festoon, an ornament of carved work, 
 representing a wreath or garland 
 of flowers or leaves, or both inter- 
 woven with each other : it is thick- 
 est in the middle, and small at each 
 extremity, a part often hanging 
 down below the knot. 
 
 Festoon, in architecture, an ornament 
 of carved work, in the form of a 
 wreath or garland of flowers, or 
 leaves twisted together. 
 
 Fictile, an earthen vessel or other 
 article, moulded and baked. 
 
 Fictor, among the Romans, an artist, 
 a deviser, or potter. 
 
 Fid-hammer, a tool ; a fidd at one 
 end and a hammer at the other. 
 
 Fidd is a piece of iron or wood to 
 open the strands of ropes. 
 
 Fife-rails of a ship are banisters on 
 each side of the top of the poop. 
 
 Figulus, an artist who makes figures 
 and ornaments. 
 
 Filagree, in the arts, a kind of en- 
 richment in gold and silver. 
 
 File, a well-known instrument having 
 teeth on the surface for cutting 
 metal, ivory, wood, etc. 
 
 File, a strip or bar of steel, the sur- 
 face of which is cut into fine points 
 or teeth, which act by a species of 
 cutting closely allied to abrasion. 
 When the file is rubbed over the 
 material to be operated upon, it cuts 
 or abrades little shavings or shreds, 
 
 189 
 
 which, from their minuteness, are 
 called file-dust, and in so doing the 
 file produces minute and irregular 
 furrows of nearly equal depth, leav- 
 ing the surface that has been filed 
 more or less smooth, according to 
 the size of the teeth of the file, and 
 more or less accurately shaped, ac- 
 cording to the degree of skill used 
 in the manipulation of the instru- 
 ment. The files employed in the 
 mechanical arts are almost endless 
 in variety. 
 
 Fillet, a small flat face or band, used 
 principally between mouldings to 
 separate them from each other in 
 classical architecture: in the Gothic, 
 Early English, or Decorated styles 
 of architecture, it is also used upon 
 larger mouldings and shafts. 
 
 Finial, sometimes called a pinnacle, 
 but more truly confined to the 
 bunch of foliage which terminates 
 pinnacles, canopies, pediments, etc., 
 in Gothic architecture. 
 
 Finite force, a force that acts for a 
 finite time, such as the force of 
 gravity. 
 
 Finlaysorfs Tables of the value of life 
 assurance and annuities differ in 
 several respects widely from either 
 the Northampton or the Carlisle 
 calculated Tables. In framing them 
 for Government annuities, from ob- 
 servations made on the mortality in 
 tontines and amongst the holders 
 of Government annuities, Mr. Fin- 
 layson, in his calculations, is in- 
 clined to take a favourable view of 
 the duration of human life, and his 
 Tables coincide very nearly with 
 the Carlisle, except that he makes 
 a distinction between males and 
 females, the latter being consi- 
 dered rather longer lived than the 
 former. As regards annuities, these 
 observations may be thus illus- 
 trated : the present value of an an- 
 nuity of \ for the life of a person 
 aged twenty-five, calculated at 4 
 per cent, interest, would be, ac- 
 cording to the 
 
 . s. 
 Northampton Tables 15 4 
 
FIR 
 
 FIRE-BRICKS. 
 
 FIR 
 
 Carlisle Tables . . 17 6 
 Government, Male . . 16 9 
 Do. Female . 18 1 
 
 Fire-bar frame, inalocomotive engine, 
 a frame made to fit the fire-box on 
 which the fire-bars rest: a plan of 
 dropping all the bars at once by a 
 movable frame, acted on by a lever 
 and handle outside the fire-box, 
 has been frequently tried, but the 
 action of the intense heat soon puts 
 it out of working order. 
 
 Fire-bars, in a locomotive engine, 
 wedge-shaped iron bars fitted to 
 the fire-box with the thick side 
 uppermost, to support the fire : the 
 ends rest on a frame : they are in- 
 clined inwards, with an air space 
 between each, to promote combus- 
 tion, and are jointed at one end, 
 and supported by a rod at the 
 other, so that the rod being with- 
 drawn, the bars fall, and the fire- 
 box is emptied. 
 
 Fire-box, in a locomotive engine, the 
 box (usually made of copper) in 
 which the fire is placed. The out- 
 side is of iron, separated from the 
 copper fire-box by a space of about 
 3 inches all round for water. 
 
 Fire-box door, the door opening into 
 the fire-box, facing the locomotive 
 tender, by which coke is supplied 
 to the fire. 
 
 Fire-box partition: in large fire- 
 boxes a division is made in the box, 
 into which water is admitted: this 
 division is about the height of the 
 fire-box door, and divides the fire 
 into two parts in a locomotive en- 
 gine, thereby increasing the heating 
 surface of the fire-box. 
 
 Fire-box stays, in a locomotive engine, 
 deep strong iron stays bolted to 
 the top of the copper fire-box, to 
 enable it to resist the pressure of 
 the steam : round copper or iron 
 stays are also used to connect the 
 outside shell to the inside box, in 
 the proportion of about one stay to 
 every 4 square inches of flat surface. 
 
 Fire-bricks are used for lining fur- 
 naces, and for all kinds of brick- 
 work exposed to intense heat which 
 
 190 
 
 would melt common bricks. They 
 are made from a natural compound 
 of silica and alumina, which, when 
 free from lime and other fluxes, is 
 infusible under the greatest heat to 
 which it can be subjected. Oxide 
 of iron, however, which is present 
 in most clays, renders the clay fu- 
 sible when the silica and alumina 
 are nearly in equal proportions, and 
 those fire-clays are the best in which 
 the silica is greatly in excess over 
 the alumina. When the alumina 
 is in excess, broken crucibles, glass- 
 house pots, and old fire-bricks, 
 ground to powder, are substituted 
 for the common siliceous sand used 
 in the ordinary processes of brick- 
 making, but which, in this case, 
 would be injurious, as having a 
 tendency to render the clay fusible. 
 
 Fire-clay being an expensive ar- 
 ticle, it is usual, when making fire- 
 bricks at a distance from mines, 
 to mix with it burnt clay, for the 
 sake of economizing the clay and 
 diminishing its contraction. Mr. 
 Pellatt states that Stourbridge clay, 
 when carefully picked, ground, and 
 sifted, will bear, for brick-making, 
 two proportions (by weight) of 
 burnt clay to one of native clay. 
 
 Fire-clay is found throughout the 
 coal formation, but that of Stour- 
 bridge is considered the best. The 
 fire-clays of Newcastle and Glasgow 
 are also much esteemed. Fire- 
 bricks are brought to London from 
 Stourbridge and from Wales ; the 
 latter, however, will not stand such 
 intense heat as the Stourbridge 
 bricks. 
 
 Fire-bricks are also made at the 
 village of Hedgerly, near Windsor, 
 of the sandy loam known by 
 the name of Windsor loam, and 
 these are much used in London 
 for fire-work, and also by chemists 
 for luting their furnaces, and for 
 similar purposes. 
 
 The relative merits of Windsor, 
 Welsh, and Stourbridge fire-bricks 
 are best shown by their value in 
 the market. 
 
FIR 
 
 FIREPROOF FLOORS. 
 
 FIR 
 
 The following Table shows the 
 constituents of several infusible 
 clays : 
 
 iron ores, glass-making, etc., and 
 sometimes for the linings of retort- 
 ovens : for this latter purpose they 
 
 Authority . . 
 
 Dr. Ure. 
 
 Vauquelin. 
 
 Wrightson. 
 
 Description. 
 
 Kaolin, or 
 porcelain 
 clay. 
 
 Plastic clay of 
 Forge-les-eaux. 
 
 Saggrer clay, from 
 the Staffordshire 
 potteries. 
 
 Silica . . . 
 
 52 
 
 63 
 
 54-38 
 
 Alumina . . 
 
 47 
 
 16 
 
 26-55 
 
 Iron .... 
 
 0-33 
 
 8 
 
 8-38 
 
 Lime . . . 
 
 
 
 1 
 
 
 
 Carbonic acid . 
 
 
 
 . 
 
 3-14 
 
 Water . . . 
 
 
 
 10 
 
 7-28 
 
 
 99-33 
 
 98 
 
 99-73 
 
 Remarks . . 
 
 I 
 
 Used for making 
 glass-house pots 
 and pottery. 
 
 Used for making 
 saggers and fire- 
 bricks. 
 
 The following prices are from 
 the ' Conlractor's Pocket-Book for 
 1850.' They include carriage to 
 London and delivery on the works : 
 Fire-bricks per M. . s. d. 
 Windsor ... 5 8 
 Welsh ... 8 12 
 Stourbridge. .11 60 
 Fire-bricks. The parts of furnaces 
 exposed to heat are built of bricks 
 made of a description of clay which 
 is to different extents infusible, the 
 qualities chosen for use being regu- 
 lated by the degree of heat to which 
 they are to be exposed. They are 
 known in commerce by the names 
 of Bristol, Stourbridge, Newcastle, 
 Welsh, and Windsor bricks. The 
 first of these are composed almost 
 entirely of silex, and are infusible 
 at the" greatest heat of the blast- 
 furnace ; but they are very costly, 
 and seldom used. The second 
 quality are made from clay found 
 in the neighbourhood of Stour- 
 bridge, lying in a stratum of con- 
 siderable thickness between the 
 upper soil and the coal formations : 
 they are used in the construction of 
 furnaces required to resist great 
 heat, such as those for smelting 
 
 191 
 
 are considered too expensive, ex- 
 cept for the arch immediately over 
 the furnace, as the heat is not in- 
 tense. The third variety are com- 
 posed of the clay lying above the 
 coal measures in Northumberland, 
 and for the construction of retort 
 furnaces and ovens are the most 
 desirable. 
 
 Fire-damp, in coal-mines, is impure 
 carburetted hydrogen. 
 
 Fire-place, a space within a chimney- 
 piece for the burning of fuel to 
 warm the temperature of the air, 
 and in communication with a shaft 
 or chimney-flue. 
 
 Fireproof floors. When a fire breaks 
 out in London it destroys a whole 
 building in spite of the prompt ef- 
 forts of the Brigade ; this is owing 
 to the materials used in the con- 
 struction of houses being very in- 
 flammable. In an enlightened 
 country like England, so rich in 
 iron, and commanding such power- 
 ful means of action, we ought to 
 have got rid altogether of wooden 
 floors and roofs, which are so ex- 
 pensive, so combustible, so apt to 
 wear out. 
 
 In Paris there are firms who 
 
FIR 
 
 FIRES OF THE ANCIENTS. 
 
 FIR 
 
 manufacture iron roofs and floors. 
 The Exhibition contained numerofis 
 samples of this manufacture, espe- 
 cially those exhibited by the Creu- 
 sot Foundry, consisting of a flooring 
 with its various modes of construc- 
 tion, all worthy the attention of 
 competent judges. The Creusot 
 manufacture girders offering a re- 
 sistance of 18 to 20 per cent, above 
 that obtained by any other system, 
 independently of the extra strength 
 produced by the peculiar mode in 
 which they are riveted. 
 
 The usual price of iron girders 
 in England is from 30 to 40 per 
 cent, cheaper than in Paris, and the 
 timber joists are from 30 to 40 per 
 cent, dearer ; the former are gene- 
 rally preferred in Paris on account 
 of their greater durability and their 
 being fireproof. 
 
 There are firms supplying rolled 
 iron girders in London ; plate gir- 
 ders have been found by several 
 builders more economical than 
 rolled ones, and there is no lack of 
 them. 
 
 The iron girders are prevented 
 from oxidation when imbedded in 
 mortar, and not in plaster. 
 
 In all the French systems the 
 wooden floors ('parquets') are laid 
 on small wooden joists, resting on 
 the top of the main girders, which 
 allows the ventilation required for 
 preventing the ' dry rot.' 
 Fire-tubes, or tube-flues, are those 
 through which the fire passes, for 
 obtaining a large heating surface, 
 fixed longitudinally in the middle 
 compartment of a locomotive en- 
 gine, between the fire-box and 
 smoke-box. 
 
 Fires of the Ancients. Palladio says, 
 " Finding that this subject about 
 fires of the ancients had not been 
 treated of distinctly by anybody, 
 I resolved to compose something 
 about it. We are ignorant of most 
 things delivered thereupon by the 
 ancients which might give us some 
 light upon the matter : we must 
 have recourse to the inventions of 
 
 192 
 
 later times, thereby gradually to 
 obtain a more ample knowledge of 
 it. The Romans were sensible that 
 a continual flame and a great heat 
 from live coals were hurtful to the 
 eyes; they therefore went very 
 wisely about finding out a remedy. 
 They found how dangerous it was 
 to carry fire about the house from 
 one room to another. Stoves are 
 an abominable invention : they 
 cause a continual stench, swell the 
 head, and make men drowsy, dull, 
 and lazy. Most people that use 
 them grow tender and weak : some 
 cannot stir out of these rooms all 
 the winter. The ancients used to 
 light their fire in a small furnace 
 under the earth. Thence they 
 conveyed a great many tubes of 
 different sizes into all the different 
 stories and rooms of the house, 
 which tubes or pipes were invisi- 
 ble, but laid in the thickness of the 
 walls and ceilings, just like water- 
 pipes. Each of these opened at 
 that part of the furnace which 
 joined to the very wall of the house, 
 and through these ascended the 
 heat, which was let in whenever 
 they had a mind it should, whether 
 in dining-rooms, bed-chambers, or 
 closets, much in the manner as we 
 see the heat or steam of water 
 contained in an alembic to ascend 
 and warm the parts most distant 
 from the fire-place. The heat in 
 that manner used to spread so 
 equally that it warmed the whole 
 house alike. It is not so with 
 chimneys or hearths; for if you 
 stand near, you are scorched ; if at 
 any distance, you are frozen ; but 
 here a very mild warm air spreads 
 all around, according as the fire 
 that warms the pipes laid along the 
 wall opposite to the hearth is more 
 or less burning. Those pipes which 
 dispensed the heat did not open 
 into the very furnace, on purpose 
 that neither smoke nor flame should 
 get into them, but only a warm 
 steam should enter, which they let 
 out again ; thereby creating a con- 
 
FIR 
 
 FLAMBLOYANT STYLE. 
 
 FLE 
 
 tinual moderate heat. The fire 
 needed not to be large, provided 
 it was continual, to supply those 
 confined and enclosed pipes with a 
 sufficient power of wanning. They 
 dressed their meat at the mouth of 
 the furnace; and all along the 
 walls were disposed kettles, or 
 other vessels, filled with hot water, 
 to keep the meat warm." 
 
 Fir-poles, small trunks of fir-trees, 
 from 10 to 16 feet in length ; used 
 in rustic buildings and out-houses. 
 
 Fish, a machine employed to hoist 
 and draw up the flukes of a ship's 
 anchor towards the top of the bow, 
 in order to stow it after it has 
 been catted. 
 
 Fissure, or Gulley, is that crack or 
 split in the strata of the earth 
 which is the receptacle of mineral 
 particles, whose contents are styled 
 a ' lode.' 
 
 Fistuca, among the Romans, an in- 
 strument used for ramming down 
 pavements and threshing-floors, 
 and the foundations of buildings. 
 
 Fistula, a water-pipe, according to 
 Vitruvius, who distinguishes three 
 modes of conveying water : by 
 leaden pipes, by earthen pipes, and 
 by channels of masonry. 
 
 Five species of temples (the). There 
 are five species of temples : namely, 
 the pycnostyle, in which the co- 
 lumns are placed far apart ; the 
 systyle, in which they are more 
 remote ; the diastyle, whose co- 
 lumns are at an ample distance 
 from each other; the araeostyk, in 
 which the intervals between the 
 columns are too great ; and the 
 eustyle, whose intercolumniations 
 are justly proportioned. In the 
 pycnostyle species the interval be- 
 tween the columns is equal to one 
 diameter and a half: there is an 
 instance of this in the temple of 
 Julius, and another in the temple 
 of Venus, which is erected in the 
 forum of Ca3sar: in all temples of 
 this species the same interval be- 
 tween the columns is observed. In 
 the systyle species there should be 
 
 193 
 
 an interval between the columns 
 equal to two diameters : this ar- 
 rangement would leave the space 
 between the plinths of the bases of 
 the columns equal to the extent of 
 the plinths themselves. 
 
 Flag, a national colour, a standard. 
 
 Flag, a stone for pavement. 
 
 Flake-white is an English white lead, 
 in the form of scales or plates, 
 sometimes grey on the surface. It 
 takes its name from its figure, is 
 equal or sometimes superior to 
 crems white, and is an oxidized 
 carbonate of lead, not essentially 
 differing from the best of the 
 above. Other white leads seldom 
 equal it in body ; and when levi- 
 gated, it is called ' body-white.' 
 
 Flamboyant Style of Architecture, 
 the decorated and very ornamental 
 style of architecture of French in- 
 vention and use, and contemporary 
 in France with the Perpendicular 
 style in England. One of the most 
 striking and universal features is 
 the waving arrangements of the 
 tracery of the windows, panels, etc. 
 The foliage used for enrichments 
 is well carved, and has a playful 
 and frequently a good effect. 
 
 Flanders varnish: dissolve grain 
 mastic in alcohol : this operation is 
 requisite to detach the impurities 
 in the resin. The proportion of 
 spirit ought to be sufficient to cover 
 the mastic, and % part more. 
 
 Planning, the internal splay of a win- 
 dow-jamb. 
 
 Flaring, in ship-building, over-hang- 
 ing, as in the top side forward. 
 
 Flatting, in house-painting, a mode 
 of painting in oil in which the 
 surface is left, when finished, with- 
 out gloss. The material is pre- 
 pared with a mixture of oil of tur- 
 pentine, which secures the colours, 
 and, when used in the finishing, 
 leaves the paint quite dead. 
 
 Flemish bricks are used for paving : 
 seventy-two will pave a square 
 yard : they are of a yellowish co- 
 lour, and harder than the ordinary 
 bricks. 
 
FLE 
 
 FLORENTINE SCHOOL. 
 
 FLO 
 
 Flemish School of Painting. This 
 school is highly recommended fb 
 the lovers of the art by the disco- 
 very, or at least the first practice, 
 of painting in oil. It has been 
 generally attributed to John Van 
 Eyck, who was, it is said, accus- 
 tomed to varnish his distemper 
 pictures with a composition of oils, 
 which was pleasing on account of 
 the lustre it gave them. In the 
 course of his practice he came to 
 mix his colours with oil, instead of 
 water, which he found rendered 
 them brilliant without the trouble 
 of varnishing. From this and sub- 
 sequent experiments arose the art 
 of painting in oil; and this won- 
 derful discovery, whether made by 
 Van Eyck or not, soon acquired 
 notice all over Europe. The atten- 
 tion of the Italian painters was soon 
 excited. John of Bruges was the 
 founder of painting as a profession 
 in Flanders. Peter Paul Rubens 
 was the founder of the art. 
 
 Fleur-de-Lis, the ancient trophy of 
 France. 
 
 Flight, the stairs from one landing- 
 place to another. 
 
 Float, a flat piece of stone or other 
 material attached to a valve in the 
 feed-pipe of the boiler of a steam- 
 engine, and supported upon the 
 surface of the water by a counter- 
 weight ; used either for showing 
 the height of the water, or regu- 
 lating the supply from the cistern. 
 
 Flookan, in Cornish, an earth or clay 
 of a slimy, glutinous consistence; 
 in colour for the most part blue 
 or white, or compounded of both. 
 
 Floor-hollow, in ship-building, an el- 
 liptical mould for the hollow of the 
 floor-timbers and lower futtocks. 
 
 Flooding, among miners, the inter- 
 ception of ore by the crossing of 
 a vein of earth or stone. 
 
 Floors, in early English domestic ar- 
 rangements, were generally covered 
 with rushes, carpets being seldom 
 used for such purposes even at the 
 close of Elizabeth's reign, although 
 instances occur of tapestry cloths 
 
 194 
 
 for the feet to rest upon as early 
 as Edward I. It does not, indeed, 
 appear to have been the custom 
 at any time to leave floors bare, 
 whether boarded or paved. Our 
 poets, and particularly Shakespeare, 
 all speak of rushes and other vege- 
 table substances being strewed in 
 the principal apartments. 
 
 Floor-timbers, in ship-building, are 
 those placed immediately across 
 the keel, and upon which the bot- 
 tom of the ship is framed. 
 
 Floran, an exceedingly small-grained 
 tin, scarcely perceivable in the 
 stone, though perhaps very rich. 
 
 Florentine lake colour is extracted 
 from the shreds of scarlet cloth : 
 the same may be said also of 
 Chinese lake. 
 
 Florentine School of Painting. This 
 school is remarkable for greatness ; 
 for attitudes seemingly in motion ; 
 for a certain dark severity ; for an 
 expression of strength by which 
 grace is perhaps excluded ; and for 
 a character of design approaching 
 to the gigantic. The productions 
 of this school may be considered 
 as overcharged ; but it cannot be 
 denied that they possess an ideal 
 majesty which elevates human na- 
 ture above mortality. The Tuscan 
 artists, satisfied with commanding 
 the admiration, seem to have con- 
 sidered the art of pleasing as be- 
 neath their notice. This school 
 has an indisputable title to the 
 veneration of all the lovers of the 
 arts, as the first in Italy which cul- 
 tivated them. 
 
 Florentine School. Academies in Italy. 
 In 1349 the painters established 
 themselves into a religious frater- 
 nity, which they denominated ' The 
 Society of St." Luke.' This was 
 not the first that had arisen in 
 Italy, as Baldinucci affirms. 
 
 Florid Gothic, or Florid English or 
 Tudor, is a style of redundant or- 
 namentation. The period is from 
 1400-1537. There are many 
 churches of the time of HenryVII. 
 in Somersetshire. 
 
FLO 
 
 FONT. 
 
 FON 
 
 Flotilla, a Spanish term for a num- 
 ber of ships, or fleet. 
 
 Flower-garden (the) " should be an 
 object detached and distinct from 
 the general scenery of the place ; 
 and whether large or small, whe- 
 ther varied or formal, it ought to 
 be well protected from hares and 
 smaller animals by an inner fence : 
 within this enclosure rare plants 
 of every description should be en- 
 couraged, and a provision made of 
 soil and aspect for every different 
 class. Beds of bog-earth should 
 be prepared for the American 
 plants : the aquatic plants, some of 
 which are peculiarly beautiful, 
 should grow on the surface or 
 near the edges of water. The nu- 
 merous class of rock-plants should 
 have beds of rugged stone pro- 
 vided for their reception, with- 
 out the affectation of such stones 
 being the natural production of the 
 soil ; but, above all, there should 
 be poles or hoops for those kinds 
 of creeping plants which sponta- 
 neously form themselves into grace- 
 ful festoons when encouraged and 
 supported by art." 
 
 There is no ornament of a flower- 
 garden more appropriate than a 
 conservatory or greenhouse, where 
 the flower-garden is not too far 
 from the house ; but amongst the 
 refinements of modern luxury may 
 be reckoned that of attaching a 
 green-house to some room in the 
 mansion. 
 
 Fluccan, in mining, a soft, clayey sub- 
 stance, generally found to accom- 
 pany the cross-courses and slides. 
 
 Fluke, in mining, the head of a 
 charger; an instrument used for 
 cleansing the hole previous to 
 blasting. 
 
 Fluor or Fluores, a soft, transparent 
 kind of mineral concretion. 
 
 Flush, a term common to workmen, 
 and applied to surfaces which are 
 on the same plane. 
 
 Flutlngs or Flutes, the hollows or 
 channels cut perpendicularly in the 
 shafts of columns, etc., in classical 
 
 architecture : they are used in the 
 Doric, Ionic, Corinthian, and Com- 
 posite orders. 
 
 Flux, in metallurgy, saline matters 
 which facilitate the fusion of ores 
 and other substances which are not 
 easily fusible in assays ; used also 
 in the reduction of ores. 
 
 Fly, in mechanics, that part of a 
 machine which, being put in mo- 
 tion, regulates the rest. 
 
 Fly-wheel, a wheel with a heavy rim, 
 fixed upon the crank-shaft of a land 
 engine, for the purpose of equaliz- 
 ing the motion by the centrifugal 
 force absorbing the surplus force 
 at one part of the action, to dis- 
 tribute it again when the action is 
 deficient. 
 
 Flyers, stairs that go straight and do 
 not wind, the fore and back part of 
 each stair and the ends respectively 
 being parallel to each other. 
 
 Focus, among the Romans, an altar, 
 a fireplace or hearth : hence the 
 Latin motto, " Pro aris et focis," 
 "for our altars and firesides." 
 
 Fodina, a mine or quarry. 
 
 Foye, Cornish, a forge or blowing- 
 house for smelting tin. 
 
 Foils, foliation ; the spaces between 
 the cusps of the featherings of 
 Gothic architecture. 
 
 Fons, a font or a natural spring of 
 water, frequently converted into or- 
 namented fountains by the Greeks 
 and the Romans. The latter also 
 erected edifices of various degrees 
 of splendour over natural springs, 
 such as the grotto of Egeria. near 
 Rome, where the natural cave is 
 converted by the architect into a 
 temple. 
 
 Font, the vessel which contains the 
 water for the purposes of baptism. 
 The font is the only relic of our 
 ancient architecture which in its 
 form is at all analogous to the 
 Grecian and Roman vases. The 
 shape which has at different pe- 
 riods been given to it is a subject 
 of some interest. Norman fonts 
 are generally square or circular; 
 the first frequently placed on five 
 
 195 
 
 K 2 
 
FOG 
 
 FORCING-PUMP. 
 
 FOR 
 
 legs ; but which may be the older 
 form, the square or circle, is not 
 yet known. The circular form 
 continued to be much used during 
 the Early English period ; so, occa- 
 sionally, was the square. Through- 
 out the continuance of the Deco- 
 rated style, the octagon was gene- 
 rally used, sometimes the hexagon. 
 During the Perpendicular style, the 
 octagon was almost always used. 
 Until the Reformation, and occa- 
 sionally after, dipping was prac- 
 tised in this country. Pouring or 
 sprinkling was not unusual pre- 
 vious to the Reformation ; for as 
 early as the year 754, pouring, in 
 cases of necessity, was declared by 
 Pope Stephen III. to be lawful; 
 and in the year 1311, the Council 
 of Ravenna declared dipping or 
 sprinkling indifferent : yet dipping 
 appears to have been in this coun- 
 try the more usual mode. The 
 Earl of Warwick, who was born in 
 1831, was baptized by dipping: so 
 Prince Arthur (eldest son of Henry 
 VII.), King Edward VI., and Queen 
 Elizabeth, were all baptized in a 
 similar manner. 
 
 Font of the time of Edward II. 
 
 Foot, an ancient measure of tin, con- 
 taining two gallons ; now a nominal 
 measure, but in weight 60 Ibs. ; also 
 a lineal measure of twelve inches. 
 
 196 
 
 Foot-pace, the dais or raised floor at 
 the upper end of an ancient hall. 
 
 Foot-plate, the platform on which the 
 engine-man and fire-man of a lo- 
 comotive engine attend to their 
 duties. 
 
 Foot-stall, the plinth or base of a 
 pillar. 
 
 Foot-valve, the valve in the passage 
 between the condenser and air- 
 pump of an engine, opening towards 
 the air-pump. 
 
 Foot-waleing, the plank withinside a 
 ship, below the lower deck. 
 
 Force of the wind. Air, when in 
 continuous motion in one direction, 
 becomes a" very useful agent of 
 machinery, of greater or less energy 
 according to thevelocity with which 
 it moves. Were it not for its vari- 
 ability in direction and force, and 
 the consequent fluctuations in its 
 supply, scarcely any more appro- 
 priate first mover could generally 
 be wished for ; and even with all 
 its irregularity, it is still so useful 
 as to require a separate considera- 
 tion. 
 
 The force with which air strikes 
 against a moving surface, or with 
 which the wind strikes against a 
 quiescent surface, is nearly as the 
 square of the velocity ; or, more 
 correctly, the exponent of the ve- 
 locity varies between 2'03 and 2'05; 
 so that in most practical cases the 
 exponent 2, or that of the square, 
 may be employed without fear of 
 error. 
 
 Forceps, tongs used by smiths to take 
 the hot metal from the fire. 
 
 Force-pumps, the plunger-pumps for 
 supplying the boiler of a locomo- 
 tive engine : the plunger-rods are 
 connected to the piston-rods of the 
 steam cylinder. 
 
 Forcer, in Cornish, a small pump 
 worked by hand, used in sinking 
 small simples, dippas, or pits. 
 
 Forcing-pump (the) differs but little 
 from a syringe : the latter receives 
 and expels a liquid through the 
 same passage, but the former has a 
 separate pipe for its discharge, and 
 
FOR 
 
 FORUM. 
 
 FOR 
 
 both the receiving and discharging 
 orifices are covered with valves. 
 By this arrangement it is not ne- 
 cessary to remove a pump from the 
 liquid to transfer the contents of its 
 cylinder, as is done with the sy- 
 ringe, hut the operation of forcing 
 up water may be continuous, while 
 the instrument is immovable. A 
 forcing-pump, therefore, is merely 
 a syringe furnished with an induc- 
 tion and eduction valve, one 
 through which water enters the 
 cylinder, the other by which it es- 
 capes from it. The ordinary forcing- 
 pump has two valves : the cylinder 
 is placed above the surface of the 
 water to be raised, and consequently 
 is charged by the pressure of the 
 atmosphere : the machine, there- 
 fore, is a compound one, differing 
 from that described, which is purely 
 a forcing-pump, the water entering 
 its cylinder by gravity alone. 
 
 Forecastle, a short deck at the fore- 
 part of a ship, above the upper 
 deck, on which castles were for- 
 merly erected, or places to shelter 
 the men in time of action. 
 
 Fore-foot, the foremost piece of the 
 keel of a vessel. 
 
 Foreground, the front of a picture. 
 
 Foreyn, an ancient term to signify a 
 drain or cesspool. 
 
 Forge, a smith's furnace for heating 
 metals, to render them soft and 
 more malleable. 
 
 Fork, a short piece of steel which fits 
 into one of the sockets or chucks 
 of a lathe, and is used by wood- 
 turners for carrying round the piece 
 to be turned ; it is flattened at the 
 end like a chisel, but has a pro- 
 jecting centre-point, to prevent the 
 wood from moving laterally. 
 
 Fore-locks, in a ship, little flat wedge- 
 like pieces of iron, used at the ends 
 of bolts to keep the bolts from fly- 
 ing out of the holes. 
 
 Foreshorten, in painting, is when a 
 head or face in a draught is made 
 to appear shorter before. 
 
 Form : 1. General form : figure, shape, 
 configuration, make, formation, 
 
 frame, construction, conformation, 
 effbrmation, mould, fashion. 2. 
 Special form. 3. Superficial form. 
 
 Formosity, beauty, fairness, etc. 
 
 Form-peys, an ancient term for form- 
 pieces ; the lower terminations of 
 mullions which are worked upon 
 sills. 
 
 Forms and motions of tools. The 
 principles of action of all cutting 
 tools, and of some others, whether 
 guided by hand or by machinery, 
 resolve themselves into the simple 
 condition, that the work is the 
 combined copy of the form of the 
 tool and of the motion employed : 
 thus the geometrical definitions 
 employed convey the primary ideas 
 of lines, superficies, and solids ; that 
 is, the line results from the motion 
 of a point, the superficies from the 
 motion of a line, and the solid from 
 the motion of a superficies. 
 
 Formula (pi. Formulas), a prescribed 
 rule in arithmetic or mathematics ; 
 a maxim : in law, an action, process, 
 or indictment. 
 
 Formulary, a book containing set 
 forms, rules, or models. 
 
 Fornax, among the Romans, a kiln 
 for baking pottery. 
 
 Fortification, the science of military 
 architecture; a defensive building. 
 
 Forum, a large open space used by the 
 Romans for the sale of merchan- 
 dise, and for public assemblies ; 
 also a court of justice. 
 
 Forum and Basilica. The Greeks 
 built their forum with spacious 
 porticoes, two tiers in height, ar- 
 ranged in a square form ; the co- 
 lumns of the porticoes were placed 
 at small intervals from each other, 
 supporting stone or marble enta- 
 blatures ; and galleries were made 
 over the lacunaria of the lower 
 porticoes, or places of exercise. 
 In Italy, the mode of constructing 
 the forum was different ; because, 
 by a custom sanctioned by its anti- 
 quity, the show of gladiators was 
 exhibited there ; and therefore the 
 intervals between the columns sur- 
 rounding the area were greater. 
 
 197 
 
FOS 
 
 FOSSES D'AISANCES. 
 
 FOS 
 
 The lower porticoes were occupied 
 as the offices of bankers, which sit- 
 uation was calculated to facilitate 
 the management of the public re- 
 venue : the upper contained seats 
 for the spectators of the diversions 
 practised in the forum. 
 
 Forward, the fore part of a ship. 
 
 Fosses d' Aisances : the cesspools of 
 Paris are so called ; and they are 
 usually made 3 m -00 long in the 
 clear by l m -70, by l m -50, to the 
 springing of the semicircular head 
 (9 ft. 10 in. x 5 ft. 7 in. x 4 ft. 11 
 in. English, nearly) : a man-hole, 
 l m -00 by O m -35 is left for the pur- 
 poses of emptying and visiting them 
 (3 ft. 3 -^ in. x 1ft. 2 in.). The walls 
 which surround them, as well as 
 the bottom, are exclusively formed 
 of such materials as are most effi- 
 cacious in preventing the filtra- 
 tion of the matters contained with- 
 in them. Of late years the usual 
 custom has been to employ the 
 meuliere, or mill-stone, bedded in 
 mortar composed of lime and ce- 
 ment, the inside being well point- 
 ed, and rendered throughout with 
 this mortar. No cesspool is al- 
 lowed to be used until after an exam- 
 ination, to be certified by the mu- 
 nicipal authority. Any infiltration 
 to a neighbour's property gives a 
 title to damages, and the architect 
 and builder are both responsible 
 
 > for ten years to the proprietor, as 
 also to the neighbours, in case any 
 nuisance arises from defects in the 
 execution of the works. 
 
 When the cesspools require clean- 
 ing, notice is given to the Board 
 of Public Health ('aux Agents de la 
 Saluhrite publiqne'), who authorize 
 and direct the operations. In win- 
 ter these are carried on between 
 10 P.M. and 7 A.M.; and in sum- 
 mer, between 11 P.M. and 6 A.M. 
 The carts, as well as all the other 
 material of the nightmen, are under 
 the inspection of the above-named 
 officers, and must be, as nearly as 
 possible, both water-tight and air- 
 tight. They contain not more than 
 
 20 m -00 cube each, or nearly 71 ft. 
 cube English. 
 
 The contents of the cesspools are 
 usually (especially in the modern 
 houses) sufficiently fluid to allow 
 of their extraction by pumps. In 
 this case a small furnace is placed 
 over the bung of the cart, to burn 
 the gas as it rises : the bung itself 
 is plastered over directly the cart 
 is filled. When the contents are too 
 solid to be pumped out, they are 
 conveyed from below in small ves- 
 sels of wrought iron, called ' tin- 
 ettes,' holding about 3| feet ( T yh 
 of a metre cube) each ; and the 
 lids are plastered over before the 
 vessels are removed from the cess- 
 pool. 
 
 Of late years a system of what 
 are called 'fosses mobiles' has been 
 introduced into the better class of 
 houses. It consists of air-tight 
 tubs, placed in a vault (rendered 
 also as air-tight as possible), which 
 receive the ends of the soil-pipes. 
 These tubs are removed at stated 
 intervals, the openings plastered 
 over, and may in that state be 
 transported at any time of the day. 
 This system obviates the terrible in- 
 fection of the old kind of cesspool, 
 and is gaining rapidly. Indeed, as 
 the French people are fond of gilt 
 ornaments in their dwellings, and 
 the gases from the cesspools turn 
 them black at once, unless great 
 precautions be observed in cover- 
 ing them, whenever a cesspool is 
 opened, it is easy to understand that 
 the 'fosses mobiles,' which obviate 
 this inconvenience, should become 
 of general use. 
 
 Until of late, all the carts were 
 obliged to pass through the Bar- 
 riere du Combat to deposit their 
 contents at the laystalls of Mont- 
 faucon ; but some new works have 
 been constructed at Bony, so as to 
 allow the suppression of this gigan- 
 tic nuisance at the immediate gates 
 of Paris. 
 
 The cleaning of the cesspools of 
 Paris is executed by several private 
 
FOS 
 
 FOSSES D'AISANCES. 
 
 FOS 
 
 companies, the most important of 
 which is ' La Compagnie Richer,' 
 who do at least one-half of this 
 business: their capital was about 
 200,000, in land, plant.and build- 
 ings. They employ 150 horses and 
 300 men, of whom 60 are for the 
 repairs of the plant. Their charge 
 is 8f., 9f., and lOf. per metre cube 
 (35 feet English, nearly), accord- 
 ing to the distance. 
 
 No cesspool is allowed to be used 
 after being emptied until it has 
 been visited by an ' Agent de la 
 Salubrite,' to ascertain whether it 
 be water-tight. 
 
 The laystalls of Moritfancon con- 
 sist of two large reservoirs, at a 
 high level, into which the carts are 
 emptied. These reservoirs are about 
 2\ acres superficial, and apparently 
 12 feet deep, with a dam between 
 them, to allow of one being used 
 when the other is being emptied. 
 An overflow drain, with sluice-gates 
 at each end, allows the liquid matter 
 to run off to a large basin on a 
 lower level, where it deposits any- 
 thing which may be merely in a 
 state of mechanical suspension. On 
 the banks of this reservoir are some 
 important sal-ammoniac works. In 
 the centre is also a sluice-gate, which 
 allows the surplus liquid matters to 
 pass into two smaller reservoirs, 
 where deposition takes place with- 
 out any interference from the pump- 
 ing apparatus of the chemical works. 
 From thence the waters pass off into 
 four other basins, in which any 
 fertilizing properties they may con- 
 tain are precipitated by means of 
 straw, dead leaves, etc., and the 
 water, comparatively pure, is at 
 length let off into the main sewer, 
 which discharges itself into the 
 Seine, below Paris. The surface 
 of the intermediate basins is about 
 250 m> by 60 m - (or 3| acres) ; that 
 of the four last basins is about 350 m> 
 by 110 m - (or nearly 9 acres). 
 
 These reservoirs do not belong 
 to the city of Paris, and some diffi- 
 culties have arisen from the pro- 
 
 199 
 
 posal to remove them : all the carts 
 containing the night-soil being 
 obliged to discharge at Montfau- 
 con, the farming of the contents 
 of the basins became a source of 
 considerable profit. They were let 
 on the last occasion for a sum of 
 500,500francs per annum (20,020 
 sterling) ; the previous letting hav- 
 ing been 166,000 francs (6640 
 sterling). The increased rent and 
 the exorbitant wages paid during 
 the republican excitement of 1848 
 proved injurious to the company. 
 The ground occupied by the town, 
 moreover, is not sufficiently exten- 
 sive for the operations connected 
 with the manipulation of the ' pou- 
 drette,' and the company were 
 obliged to rent about 1\ acres more 
 land for the purpose of spreading 
 and drying the compost. The land 
 necessary for this operation had 
 been taken on lease by the out- 
 going company, and they succeed- 
 ed in obtaining a sum of 60,000 
 for the remainder of their term, as 
 no other land was to be had in the 
 neighbourhood. 
 
 Thereat and labour in conversion 
 costs the company from 12,000 
 to 16,000 per annum. The 'pou- 
 drette ' is sold to agriculturists at 
 8 francs le setier, a measure equal 
 to 12 bushels English. 
 
 In one plan adopted for empty- 
 ing the cesspools, the carts are 
 made of strong boiler plate ; they 
 are placed under an air-pump, 
 and exhausted ; the pipes are con- 
 nected with the carts and the cess- 
 pools, and the atmospheric pressure 
 on the latter forces up the liquid 
 contents. 
 
 Investigations have been made 
 respecting the general health of 
 the workmen employed at Mont- 
 faucon, the reservoir of all the ex- 
 crementitious matter of a city which 
 contains about 1,000,000 "inhabi- 
 tants, and it has been ascertained, 
 that although they were riot af- 
 fected by the cholera in 1849, they 
 are very short-lived men : acute 
 
FOS 
 
 FOUNDATIONS. 
 
 FOU 
 
 fevers, andgangrene on theslightest 
 accident, carry them off in a fright- 
 ful manner. Unfortunately the 
 dwellers in the neighbourhood also 
 are subject to the same action, and 
 the mortality from these causes is 
 very great. 
 
 The action of the ' poudrette ' 
 upon agriculture is somewhat ex- 
 traordinary. In the time of Henri 
 Quatre, the wines of Suresneswere 
 highly esteemed : the vines pro- 
 duced little, but of a superior 
 quality: since the poudrette has 
 been used to force them, the quan- 
 tity of their produce has been in- 
 creased, but the quality has totally 
 changed : from a superior rank, the 
 wines of the neighbourhood of Paris 
 have fallen to that of what is vul- 
 garly called ' du petit bleu.' 
 
 Fossatum, a ditch, or a place fenced 
 with a ditch or trench. 
 
 Fossil, a mineral, many kinds of which 
 are peculiarly and elegantly shaped. 
 
 Fossiliferous, a geological term ap- 
 plied to a district abounding in 
 fossils. 
 
 Foundations, according to Palladio, 
 ought to be twice as thick as the 
 walls to be raised upon them, so 
 that both the quality of the earth 
 and the greatness of the building 
 are to be regarded, making the 
 foundations larger in a soft and 
 loose ground, or where there is a 
 great weight to be supported. The 
 plane of the trench must be as level 
 as possible, so that the weight may 
 press equally, and not incline more 
 on one side than the other, which 
 occasions the cleaving of the walls. 
 For this reason the ancients were 
 accustomed to pave the plane with 
 Tivertine ; but we most commonly 
 lay planks or beams to build on. 
 The foundations ought to be made 
 sloping, that is to say, to diminish 
 as they rise ; but yet in such a 
 manner that the middle of the wall 
 above may fall plumb with the mid- 
 dle of the lowest part ; which must 
 be also observed in the diminution 
 of walls above ground, because by 
 
 200 
 
 that means the building becomes 
 much stronger than by making the 
 diminution any other way. 
 
 Sometimes, to avoid charges, 
 (especially in marshy grounds, 
 where there is a necessity to use 
 piles,) foundations are arched like 
 a bridge, and the walls are built 
 upon those arches. In great build- 
 ings it is very proper to make 
 vents through the body of the 
 walls from the foundations to the 
 roof, because they let forth the 
 winds and other vapours, which 
 are very prejudicial to buildings : 
 they lessen the charges, and are 
 of no small convenience, espe- 
 cially when there is occasion for 
 winding-stairs from the bottom to 
 the top. If it be necessary to 
 construct vaults below ground, 
 their foundations must be more 
 substantial than the walls of the 
 buildings which are to be raised 
 upon them. The walls, pillars, 
 and columns of the latter must 
 be placed immediately over those 
 below them, so that solid may bear 
 upon solid ; for if walls or columns 
 project beyond the substructure, 
 their duration must necessarily be 
 short. 
 
 The value of concrete in founda- 
 tions was rendered obvious in a 
 building erected by Mr. Clegg at 
 Fulham, in 1829. The foundation 
 was a quicksand. After the exca- 
 vation was got out to the depth of 
 15 feet, an iron rod sunk, with 
 little more than its own weight, 
 15 feet more; it was, in fact, as 
 bad a foundation as could possibly 
 occur. In about twelve days after 
 it was built, it had settled bodily 
 down 16 inches, without a crack, 
 or deviating in the least from the 
 plumb. It therefore follows, that 
 the only disadvantage attending a 
 bad natural foundation is the ex- 
 pense of making an artificial one. 
 The following extract relates to the 
 erection of an extensive building 
 upon bad ground. 
 
 " The building for the Albion 
 
FOU 
 
 FOUNDATIONS. 
 
 FOU 
 
 Mills was erected upon a very soft 
 soil, consisting of the ' marie ground' 
 at the abutment of Blackfriars' 
 Bridge : to avoid the danger of 
 settlement in the walls, or the ne- 
 cessity of going to a very unusual 
 depth with the foundations, Mr. 
 Rennie adopted the plan of forming 
 inverted arches upon the ground 
 over the whole space upon which 
 the building was to stand, and for 
 the bottom of the dock. For this 
 purpose the ground upon which all 
 the several walls were to be erected 
 was rendered as solid as is usual 
 for building by driving piles where 
 necessary, and then several courses 
 of large flat stones were laid to 
 form the foundations of the several 
 walls ; but to prevent any chance 
 of these foundations being pressed 
 down in case of the soft earth 
 yielding to the incumbent weight, 
 strong inverted arches were built 
 upon the ground between the foun- 
 dation courses of all the walls, so 
 as to cover the whole surface in- 
 cluded between the walls ; and the 
 abutments or springings of the in- 
 verted arches being built solid into 
 the lower courses of the foundations, 
 they could not sink unless all the 
 ground beneath the arches had 
 yielded to compression, as well as 
 the ground immediatelybeneath the 
 foundation of the wails. By this 
 method the foundations of all the 
 walls were joined together so as to 
 for m one immense base,which would 
 have been very capable of bearing 
 the required weight, even if the 
 grouiid had been of the consistency 
 of mud ; for the whole building 
 would have floated upon it as a 
 ship floats in water ; and whatever 
 sinking might have taken place, 
 would have affected the whole 
 building equally, so as to have 
 avoided any partial depressions or 
 derangement of the walls ; but the 
 ground being made tolerably hard, 
 in addition to this expedient of 
 augmenting the bases by inverted 
 arches, the building stood firm." 
 
 When the foundation has been 
 properly disposed of, the brick- 
 work may be commenced. The 
 bricks should be well burned, and 
 set with a thin joint, four crosses 
 not occupying more depth than 
 llf inches. 
 
 Foundations of Temples. In preparing 
 foundations for works of this kind, 
 it will be first necessary to dig down 
 to a regular stratum, if such is to 
 be met with ; and upon this the 
 foundations, constructed with great 
 attention to their strength, are to 
 be laid : their solidity must be pro- 
 portioned to the magnitude of the 
 building 1n contemplation. The 
 piers above-ground, below the co- 
 lumns, should be thicker than the 
 diameter of the columns they are 
 to support by one-half, that these 
 substructures, which are called ste- 
 reobatae, on account of their sus- 
 taining the whole weight, may be 
 enabled by their greater solidity to 
 support what is built upon them. 
 The bases of the columns, when 
 fixed, ought not to project before 
 the face of the stereobata on either 
 side. The intervals between the 
 piers should either be made solid 
 by means of piles, or arched over, 
 so as to connect the piers. 
 
 If no compact stratum is to be 
 found, but the ground, on the con- 
 trary, is loose or marshy to a great 
 depth, trenches must be dug, and 
 piles of charred alder, olive, or oak, j 
 placed close together, be driven in 
 by means of machines : the inter- 
 vals between them should be filled 
 up with charred timber, and upon 
 this substratum the foundations 
 should be formed with solid ma- 
 sonry. The foundations being reared 
 to the same level all round, the 
 stylobate is next to be constructed. 
 Upon this the columns are to be 
 arranged, in the manner already 
 described, at intervals which are 
 determined by the species of temple 
 intended to be built, whether pyc- 
 nostyle, systyle, diastyle, or eustyle. 
 In the araostyle species the co. 
 
 201 
 
 K3 
 
FOU 
 
 FREEMASON. 
 
 FRE 
 
 lumns may be placed at any dis* 
 tance asunder. 
 
 Foundations of a Bridge : these con- 
 sist, properly, of the underground 
 work of the piers and abutments, 
 which it is within the province of 
 a civil engineer to construct : the 
 necessity of firmness and solidity 
 in the execution of such works 
 will be deemed of importance just 
 in proportion to the intended ex- 
 tent and magnificence of the struc- 
 ture they are designed to support. 
 
 Foundemaunt, foundation. (Chaucer.") 
 
 Foundery, in iron works, the space 
 of six days. 
 
 Foundry, a place where masses of 
 metal are melted and run into 
 moulds, so as to assume the re- 
 quired form. 
 
 Four-way -cock, a cock having two 
 separate passages in the plug, and 
 communicating with four pipes. 
 
 Fox-tail wedging, in carpentry. This 
 is done by sticking into the point 
 of a wooden bolt a thin wedge of 
 hard wood, which when the bolt 
 reaches the bottom of the hole, 
 splits, expands, and secures it. 
 
 Frame, the strong frame-work, out- 
 side the wheels, which supports the 
 boiler and machinery on the axles 
 of a locomotive engine. 
 
 Frame, inside, in locomotive engines. 
 Some engines have the support- 
 ing frames within the wheels, and 
 are called inside-framed engines. 
 Besides this frame, resting on the 
 axles, there are also other strong 
 stays from the fire-box to the 
 smoke-box, called inside framing 
 or stays, for supporting the works 
 and strengthening the boiler. 
 
 Frames, the bends of timbers that are 
 bolted together: in small ships there 
 are two bolts in every shift of 
 timber, and three in large ships. 
 The bolts should be disposed clear 
 of the chain and preventer-bolts, 
 scupper, lodging knee-bolts, and 
 port cells. 
 
 Frankfort -black is said to be made of 
 the lees of wine from which the 
 tartar has been washed, by burn- 
 
 ing in the manner of ivory-black. 
 Fine Frankfort-black, though al- 
 most confined to copper-plate 
 printing, is one of the best black 
 pigments we possess, being of a 
 fine neutral colour, next in intensity 
 to lamp-black, and more powerful 
 than that of ivory. 
 
 Frater-house, the refectory or hall of 
 a monastic establishment. 
 
 Fredstole, a seat near the altar. 
 
 Freedom, in drawing, is a bold and 
 spirited manner, with evident li- 
 berty of the pencil ; i. e. where the 
 drawing is apparently accomplish- 
 ed with ease. 
 
 Freemason, as applied to ancient ar- 
 chitecture : a person learned in the 
 art of building, more particularly 
 in ecclesiastical construction, and 
 who, by his learning in the science 
 and his taste in the construction of 
 edifices, travelled from one country 
 to another, and executed models of 
 everlasting renown. The term may 
 also be applied to a free-stone 
 mason, or a cutter and worker in 
 stone, without reference to the so- 
 ciety called Freemasons. 
 
 Free-stone, building stone which may 
 be easily cut into blocks and worked 
 with a chisel ; so called from having 
 no grain : it may therefore be cut 
 in any direction. 
 
 Free-stuff, that timber or stuff which 
 is quite clean or without knots, 
 and works easily, without tearing. 
 
 French chalk is an indurated mag- 
 nesian mineral, employed to re- 
 move grease stains. 
 
 French School of Painting. This 
 school has been so different under 
 different masters, that it is difficult 
 to characterize it. Some of its 
 artists have been formed on the 
 Florentine and Lombard styles, 
 others on the Roman, others on 
 the Venetian, and a few of them 
 have distinguished themselves by a 
 style which may be called their 
 own. In speaking in general terms 
 of this school, it appears to have 
 no peculiar character, and can only 
 be distinguished by its aptitude to 
 
FRE 
 
 FRIARS. 
 
 FUL 
 
 imitate easily any impressions ; and 
 it may be added, speaking still in 
 general terms, that it unites in a 
 moderate degree the different parts 
 of the art, without excelling in any 
 one of them. 
 
 Fresco, a kind of painting performed 
 on fresh plaster, or on a wall co- 
 vered with mortar not quite dry, 
 and with water-colours. The plaster 
 is only to he laid on as the painting 
 proceeds, no more being done at 
 once than the painter can despatch 
 in a day. The colours, being pre- 
 pared with water, and applied over 
 plaster quite fresh, become incor- 
 porated with the plaster, and re- 
 tain their beauty fora great length 
 of time. The Romans cut out 
 plaster paintings on brick walls at 
 Sparta, packed them up in wooden 
 cases, and transported them to Rome. 
 Fret, an ornament used in classical ar- 
 chitecture, formed by small fillets in- 
 tersecting each other at right angles. 
 Friars (\\\Q orders of) in England and 
 Wales, previous to their abolition, 
 including the Nuns Minoresses, 
 amounted to 
 
 Black or Dominican friars . 54 
 Grey or Franciscan friars . 62 
 Minoresses or nuns of the 
 
 order of St. Clare ... 4 
 Friars of the order of the 
 Holy Trinity for the re- 
 demption of captives . . 12 
 Order of the Carmelites or 
 
 White friars .... 50 
 Crutched or Crossed friars 10 
 
 Austin friars 32 
 
 Friars de poenitentia or of 
 
 the sac 9 
 
 Bethlernite friars .... 6 
 Friction, the act of rubbing two bodies 
 together, or the resistance in ma- 
 chines caused by the contact of 
 different moving parts. Friction is 
 proportional to the pressure ; that 
 is, everything remaining the same, 
 the friction increases as the pres- 
 sure increases. 
 
 Friction-clutch, a shell or box fixed 
 on the end of a driving shaft, fitted 
 by a conical piece which slides on 
 
 203 
 
 a feather, or raised part, at the end 
 of another shaft, so that it can be 
 engaged at pleasure by the cone 
 being forced into the shell by a 
 lever or screw. This apparatus 
 is very useful for driving machines, 
 the parts of which are subjected to 
 violent strains, as the pressure upon 
 the clutch can be regulated so as to 
 allow it to slide when the strain is 
 too great to be borne safely by the 
 machine. 
 
 Frieze, the middle division of an en- 
 tablature, that which lies between 
 the architrave and the cornice. 
 
 Frigatron, a Venetian vessel, built with 
 a square stern, without any fore- 
 mast, having only a main-mast and 
 bowsprit. 
 
 Frigidarium, the cold bathing-room 
 in the baths of the ancients, as well 
 as the vessel in which the cold water 
 was received. 
 
 The cold bath : the reservoir of 
 cold water in the hypocaustum, or 
 stove room, was termed ahenum 
 frigidarium. 
 
 Friths tool or Freedstool, a seat or chair 
 near the altar, for those especially 
 who sought the privilege of sanc- 
 tuary. 
 
 Frontal, or Fronter, the hanging 
 with which the front of an altar 
 was formerly covered. 
 
 Fronton, a French word to express an 
 ornament over a door or pediment. 
 
 Frowy stuff, short or brittle and soft 
 timber. 
 
 Frumstall, a chief seat or mansion 
 house. 
 
 Fucus, a name given by the Romans 
 to certain false dyes and paints. 
 
 Fuel, the matter or aliment of fire. 
 
 Fulcrum, the prop orsupport by which 
 a lever is sustained. 
 
 Fullers'' -earth, a soft unctuous marl, 
 used by fullers in the process of 
 cleansing cloth, etc. 
 
 Fulling-mill, an engine or mill, in 
 which cloth is cleansed by being 
 beaten with hammers. 
 
 Fulminating gold or silver, in che- 
 mistry, ammonia combined with 
 the oxides of gold or silver. 
 
UM 
 
 FURNACE. 
 
 PUT 
 
 7 umarium, a chimney; an upper 
 room used among the Romans for 
 collecting the smoke from the 
 lower apartments : used also for 
 smoking or ripening wines. 
 'uor, among carpenters, a piece 
 nailed upon a rafter to strengthen 
 it when decayed. 
 
 Burling, in navigation, the wrapping 
 up and binding of any sail close to 
 the yard. 
 ? urlong, a measure of length, the 
 
 eighth part of a mile. 
 <*urnacc. The furnace is one of the 
 mo:i important parts of the high- 
 pressure engine. The whole action 
 and power of the machine depend 
 on its construction, and on the 
 effect obtained from it, inasmuch 
 as fire is the prime agent. Too 
 much industry, exactitude, and in- 
 timate knowledge of the subject, 
 cannot be brought to bear on the 
 construction of the furnace, in order 
 to attain the two great objects of 
 its action ; namely, first, to produce 
 as perfect a combustion of the fuel 
 as possible ; and secondly, to apply 
 as much as possible of the heat so 
 developed effectively to the boiler. 
 These two requirements for a good 
 furnace are, however, not so easily 
 satisfied. Much remains to be ac- 
 quired as to the conditions under 
 which the whole of the caloric may 
 be perfectly developed from the 
 fuel, although the best manner of 
 applying the heat to the boiler is 
 well understood. 
 
 Furniture : anterior to the Tudor age, 
 household furniture was in gene- 
 ral of a rude, substantial character; 
 the tables were formed of boards 
 or trestles, the seats of massive oak 
 benches or stools, and the floors 
 strewed with straw. 
 Furniture of the hall: this consisted 
 of but few articles, such as clumsy 
 oak tables covered with carpet, 
 benches or joined forms of the 
 same material, and cupboards for 
 plate, pewter, 'treene,' leather jugs, 
 glass, etc., with a reredos or fire- 
 iron in the centre of the floor, 
 
 against which fagots were piled 
 and burned, the smoke passing 
 through an aperture in the roof; 
 the fender, formed by a raised rim 
 of stone or tile, and a 'fier fork ' and 
 tongs. 
 
 Furrings, slips of timber nailed to 
 joists or rafters, in order to bring 
 them to a level, and to range them 
 into a straight surface, when the 
 timbers are sagged, either by cast- 
 ing, or by a set which they have 
 obtained by their weight in the 
 course of time. 
 
 Fuseli (Henry), born 1741 at Zurich ; 
 died April, 1825, aged eighty-four. 
 He painted with little sympathy 
 for repose ; he thought there was no 
 dignity without action, no sublimity 
 without exaggeration. He left 
 upwards of eight hundred sketches, 
 besides splendid pictures. 
 Fusion, a founding or melting, running 
 
 metals into fluids. 
 Fust, the shaft of a column from the 
 
 astragal to the capital. 
 Fusarole, in architecture, a moulding 
 or ornament placed immediately 
 under the echinus in the Doric, 
 Ionic, and Composite capitals ; 
 the shaft of a column, pilaster or 
 pillar, or that part comprehended 
 between the shaft and the capital. 
 Fustic, a wood of a species of mul- 
 berry growing in most parts o1 
 South America, the United States 
 and the West Indies : it is a large 
 and handsome tree, principally usec 
 for dyeing greens and yellows, anc 
 also in mosaic cabinet-work anc 
 turnery. 
 
 Futtock, in ship-building. Ever; 
 single timber is called a futtock 
 and distinguished by the termi 
 lower, or first, second, third, etc. 
 except the floors, long and half-tim 
 bers, top timbers, stern timbers, etc 
 Futtocks, the lower timbers raisei 
 over the keel, and which hold th 
 ship together. 
 
 Futtock shrouds, in ship-rigging, sma] 
 shrouds that go from the main 
 mast, fore-mast, and mizen-mas 
 shrouds to those of the top-mast. 
 
GAB 
 
 GAMBOGE. 
 
 GAM 
 
 Gr. 
 
 GABLE, the upright triangular end of 
 a house, from the cornice or eaves 
 to the top of the building, some- 
 times called a sloped roof ; the up- 
 per part of a wall, above the level 
 of the eaves. Examples in Eng- 
 lish and foreign Domestic and Go- 
 thic architecture are various, and 
 generally have a most picturesque 
 effect. 
 
 Goblets, small ornamental gables or 
 canopies formed over tabernacles, 
 niches, etc. 
 
 Gad, in mining, a small punch of 
 iron with a long wooden handle, 
 used to break up the ore. 
 
 Gaff, a sort of boom used in small 
 ships to extend the upper edge of 
 the mizen, and employed for the 
 same purpose on those sails whose 
 foremost edges are joined to the 
 masts by hoops or lacings, and 
 which are usually extended by a 
 boom below: such are the main- 
 sails of sloops, brigs, and schooners. 
 
 Gage or Gauge, an instrument used 
 for measuring the state of rare- 
 faction in the air-pump, variations 
 in 'the barometer, etc. ; a measure, 
 a standard. 
 
 Gainsborough, the painter, was born 
 in 1727, in Sussex. His price for 
 a portrait rose from 5 guineas to 
 8, and until he had 40 guineas 
 for a half and 100 guineas for 
 a Avhole length. Like Reynolds, 
 he painted standing in preference 
 to sitting ; he rose early, com- 
 menced painting between 9 and 10, 
 worked 4 or 5 hours, and then 
 gave up the rest of the day to visits 
 and enjoyment. He died in 1788, 
 in the 61st year of his age, and was 
 buried in Kew churchyard. 
 
 Gal, in Cornish, rusty iron ore. 
 
 Galena, ore of silver and lead, after 
 
 the silver is extracted. 
 Galilee, a porch or chapel at the en- 
 trance of a church. The galilee at 
 Lincoln cathedral is a porch on the 
 west side of the south transept : at 
 
 205 
 
 Ely cathedral it is a porch at the 
 west end of the nave : at Durham 
 it is a large chapel at the west end 
 of the nave, which was built for the 
 use of the women, who were not 
 allowed to advance further into the 
 church than the second pillar of the 
 nave. 
 
 Gallery, an apartment generally of 
 greater length in proportion to the 
 width, applied for the purpose of 
 exhibiting pictures or sculpture : 
 used formerly in early English Do- 
 mestic architecture, in large houses, 
 as a place of resort for dancing and 
 other amusements. 
 
 Galliot, a Dutch vessel, carrying a 
 main and a mizen mast, and a large 
 gaff main-sail. 
 
 Gall-stone (colour), an animal cal- 
 culus formed in the gall-bladder, 
 principally of oxen. This concre- 
 tion varies a little in colour, but is 
 in general of a beautiful golden 
 yellow, more powerful than gam- 
 boge, and is highly reputed as a 
 water-colour: nevertheless, its co- 
 lour is soon changed and destroyed 
 by strong light, though not subject 
 to alteration by impure air. 
 
 Galvanism comprises all those elec- 
 trical phenomena arising from the 
 chemical agency of certain metals 
 with different fluids. 
 
 Galvanometer, an instrument con- 
 trived to measure minute quanti- 
 ties of electricity. 
 
 Gamboge, or, as it is variously written, 
 Gumboge, Gambouge, Cambogia, 
 Gambadium, etc., is brought from 
 Cambaja, in India, and is the pro- 
 duce of several kinds of trees. - It 
 is, however, principally obtained 
 from the tree called Gokathu,which 
 grows in Ceylon and Siam. From 
 the wounded leaves and young 
 shoots the gamboge is collected in 
 a liquid state, and dried. Gam- 
 boge is a concrete vegetable sub- 
 stance, of a gum-resinous nature, 
 and beautiful yellow colour, bright 
 
GAM 
 
 GARDENS. 
 
 GAS 
 
 and transparent, but not of a great* 
 depth. When properly used, it is 
 more durable than generally re- 
 puted, both. in water and oil, and 
 conduces, when mixed with other 
 colours, to their stability and dura- 
 bility, by means of its gum and 
 resin. It is deepened in some de- 
 gree by ammoniacal and impure 
 air, and somewhat weakened, but 
 not easily discoloured, by the ac- 
 tion of light. 
 
 Gammoning, in navigation, seven or 
 eight turns of a rope passed over 
 the bowsprit, and through a large 
 hole in the stem or knee of the 
 head, alternately, and serving to 
 bind the inner quarter of the bow- 
 sprit close down to the ship's stem, 
 in order to enable it the better to 
 support the stays of the fore-mast : 
 after all the turns are drawn as 
 firm as possible, the opposite ones 
 are braced together under the bow- 
 sprit by a frapping. 
 
 Gammoning hole, a hole cut through 
 the knee of the head, and some- 
 times one under the standard in 
 the head, for the use of gammon- 
 ing the bowsprit. 
 
 Garboard strake, the strake in the 
 bottom that is wrought into the 
 rabbet of the keel of a ship. 
 
 Gardens. The ancient plans of gar- 
 dens show that the Egyptians were 
 not less fond than our ancestors of 
 mathematical figures, of straight 
 walks, architectural decorations, 
 and vegetable avenues; and that 
 they as thoroughly entered into 
 the idea of seclusion and safety 
 suggested by enclosures within en- 
 closures. It has been remarked, 
 that in some old English places 
 there were almost as many walled 
 compartments without as apart- 
 ments within doors : the same may 
 be said of Egyptian country-houses. 
 This principle of seclusion and an 
 excessive love of uniform arrange- 
 ment are remarkably displayed in 
 the plan of a large square garden 
 given in Professor Rosellini's great 
 work. 
 
 As a subject for the painter, the 
 materials which form the scenery 
 of a garden are provided by Nature 
 herself: the artist must therefore 
 be satisfied with the degree of ex- 
 pression which she has bestowed, 
 and give the best possible disposi- 
 tion to those scanty and intractable 
 materials. In a landscape, on the 
 contrary, the painter has the choice 
 of the objects he intends to repre- 
 sent, and can give whatever force 
 or extent he pleases to the expres- 
 sion he wishes to convey, as the 
 whole range of scenery is before 
 his eye. 
 
 Garyoyle or Gurgoyle, a projecting 
 spout used in Gothic architecture, 
 to throw the water from the gutter 
 of a building off the wall. 
 
 Garland, an ornamental band used in 
 Gothic work. 
 
 Garnet, a hinge, now called a ' cross 
 garnet ;' a red gem of various sizes. 
 
 Garret, an upper apartment of a 
 house, immediately under the roof. 
 
 Garretting, small splinters of stone 
 inserted in the joints of coarse 
 masonry : they are stuck in after 
 the work is built ; flint walls are 
 very frequently garretted. 
 
 Gas. All substances,vvhether animal, 
 vegetable, or mineral, consisting of 
 carbon, hydrogen, and oxygen, 
 when exposed to a red heat, pro- 
 duce various inflammable elastic 
 fluids capable of furnishing artificial 
 light. The evolution of this elastic 
 fluid may be perceived during the 
 combustion of coal in a common 
 fire. The coal, when heated to a 
 certain degree, swells and kindles, 
 and frequently emits remarkably 
 bright streams of flame, and after a 
 certain period these appearances 
 cease, and the coal glows with a 
 red light, 
 
 The flame produced from coal, 
 oil, wax, tallow, or other bodies 
 which are composed of carbon and 
 hydrogen, proceeds from the pro- 
 duction of carburetted hydrogen 
 gas, evolved from the combustible 
 body when in an ignited state. 
 
GAS 
 
 GAS. 
 
 GAS 
 
 If coal, instead of being burnt 
 in the ordinary way, be submitted 
 to the temperature of ignition in 
 close vessels, all its immediate con- 
 stituent parts may be collected : 
 the bituminous part is distilled 
 over, in the form of coal-tar, etc., 
 and a large quantity of an aqueous 
 fluid is disengaged at the same 
 time, mixed with a portion of es- 
 sential oil and various ammoniacal 
 salts. A large quantity of carbu- 
 retted hydrogen, carbonic oxide, 
 carbonic acid, and sulphuretted 
 hydrogen, also make their appear- 
 ance, together with small quantities 
 of cyanogen, nitrogen, and free 
 hydrogen, and the fixed base of the 
 coal alone remains behind in the 
 distillatory apparatus, in the form 
 of a carbonaceous substance called 
 coke. An analysis of the coal is 
 effected by the process of destruc- 
 tive distillation ; and the products 
 which the coal furnishes may be 
 separately collected in different 
 vessels. 
 
 The carburetted hydrogen, or 
 coal-gas, when freed from the ob- 
 noxious foreign gases, may be pro- 
 pelled in streams out of small aper- 
 tures, which, when lighted, form 
 jets of flame, now called gas-lights. 
 
 Mr. Croll has patented an in- 
 vention for the purification of gas 
 from ammonia, which is effected 
 by means of dilute sulphuric acid 
 applied between the condensers 
 and the ordinary lime pu.-ifiers. 
 The vessels are made either of wood 
 or iron, and lined with lead, having 
 a w r ash-plate similar to the wet-lime 
 purifiers. The radiating bottom is 
 formed of wooden bars, for the pur- 
 pose of supporting the wash-plate 
 and distributing the gas. In com- 
 mencing the process, these vessels 
 are charged with water and sulphu- 
 ric acid in the proportion of 7 Ibs. 
 of the latter to 100 gallons of the 
 former. As the acid is neutralized 
 by the ammonia contained in the 
 gas passing through the vessels, 
 the above proportion is kept up by 
 
 207 
 
 a continuous dropping or running 
 of acid, regulated according to the 
 quantity of ammonia contained in 
 the gas, from a reservoir placed on 
 the top of the saturator. This 
 mode of supplying the acid is con- 
 tinued until the specific gravity of 
 the solution is at 11 70, or near the 
 point of crystallization ; after which 
 the supply of acid is discontinued, 
 and the liquor retained in the vessel 
 until neutralized : it is then drawn 
 off and evaporated, and yields a 
 pure sulphate of ammonia. 
 Gas (distribution of, through mains). 
 There is no branch of science con- 
 nected with the subject of gas en- 
 gineering so highly important as 
 that which relates to its conveyance 
 and distribution through pipes; 
 there is none in which theory af- 
 fords more assistance, and there is 
 hardly any branch to which so lit- 
 tle attention has been paid. The 
 interests of a gas company are not 
 best served by simply increasing 
 the quantity of gas from the same 
 quantity of coal, or improving the 
 lime machinery, etc. The laying of 
 street- mains forms the most consi- 
 derable item in the outlay ; and by 
 a judicious arrangement in the first 
 instance, much may be saved both 
 at first and last. 
 
 It is for the purpose of rendering 
 this branch of the science, and that 
 of the passage of gas through pipes, 
 perfectly plain, that the following 
 observations are here given. 
 
 When it is proposed to light any 
 town, or district of a town, with 
 gas, the first step to be taken is to 
 ascertain the number of lights, 
 both public and private, that will 
 be required, with as much accu- 
 racy as circumstances will permit ; 
 the lengih of time such lights will 
 have to burn, and the quantity of 
 gas consumed by them per hour, 
 making allowances for the increase 
 of lamps that will probably be re- 
 quired by the extension of the town. 
 The size of the works themselves 
 may be easily ascertained from this 
 
GAS 
 
 GASOMETER. 
 
 GAS 
 
 calculation. It will then remaiij 
 to fix upon a proper situation in 
 which to erect them : the best local 
 position is upon the hanks of a na- 
 vigahle river or canal, and at the 
 lowest available level, and the near- 
 est approach to such a situation is 
 advisable for obvious reasons. A 
 map of the town must be obtained, 
 or a survey made of the different 
 streets and thoroughfares : running 
 levels must be taken through them 
 at several points, and their respec- 
 tive heights marked with reference 
 to the level of the works as a da- 
 tum : upon this map all the mains 
 must be drawn, also their branches, 
 valves, and governors. Their ar- 
 rangement must be such as to allow 
 of a perfect circulation of the gas, 
 and a nearly uniform pressure at 
 the highest and lowest point. All 
 the pipes upon the same level 
 should be joined into one another, 
 and no valves used but such as are 
 necessary to shut off the gas for 
 repair of mains. To supply a higher 
 level, a governor should be placed 
 at the summit of the 'lower level, 
 with the lower main leading into 
 it. The pipe or pipes for supplying 
 the higher parts should proceed 
 from the regulating vessel. A cel- 
 lar may be appropriated for the 
 reception of this vessel. One lead- 
 ing main should be taken direct 
 from the works to an equilibrium 
 cylinder situated at some point 
 from which several streets diverge, 
 and no supply taken from this main 
 until it has reached the cylinder. 
 Branches suitable to the supply 
 of each division of the district 
 should lead from this cylinder. 
 The supply of gas to the cylinder 
 should be so regulated as to cause 
 the gas to flow along the branches 
 at an even pressure of about five- 
 tenths of an inch. If the cylinder 
 be at any considerable distance 
 from the works, a smaller main, 
 with increased pressure, may lead 
 to it, its size being sufficient to 
 equalize the discharge. 
 
 208 
 
 Supposing a district to be lighted 
 requiring 1000 public or street 
 lamps, and 7000 private burners, 
 it is usually considered that each 
 lamp on an average will consume 
 5 cubic feet of gas per hour, there- 
 fore 40,000 cubic feet will be re- 
 quired to light the district for an 
 hour ; and the leading main must 
 be capable of delivering that quan- 
 tity into the equilibrium cylinder 
 in that time. To determine the 
 size of this main, the probable in- 
 crease of lamps must be taken into 
 consideration ; and as that will de- 
 pend so much upon circumstances 
 in every instance, the judgment of 
 the engineer alone can serve to re- 
 gulate the additional area. If the 
 increase should be beyond that 
 which was expected, the gas must 
 be forced through the leading main 
 at a greater pressure. 
 
 In the above example, if the 
 diameter of main for a present con- 
 sumption be 12 inches, and to se- 
 cure an adequate supply at any 
 future period its diameter be in- 
 creased to 15 inches, the present 
 working pressure may be reduced 
 to 1 '5 of an inch instead of 3 inches ; 
 and as the leakage will also be 
 decreased, the extra-sized main 
 will not be found disadvantageous 
 even in the first instance. 
 Gasometer, a reservoir of gas, with 
 conveniences for measuring its 
 volume. The simplest and most 
 general in use consists of an iron 
 vessel, open at the bottom, and 
 inverted into a tank of water below 
 the surface of the ground, having 
 perfect freedom to rise and fall, 
 and guided by upright rods fixed at 
 several points in the circumference. 
 The diameters and numbers of the 
 vessels will vary according to the 
 magnitude of the works to which 
 the gasometer is attached, and the 
 space to be occupied by it. If the 
 works are situated in a town, where 
 the ground is too valuable to allow 
 an increased extent, a 'telescope 
 gasometer' is employed. 
 
GAS 
 
 GATES AND DOORS. 
 
 GAU 
 
 Gas-tar, commonly called coal-tar. 
 \Vheu the manufacture of gas 
 from coal was in its infancy, great 
 advantages were expected to be 
 derived from the coal-tar which 
 distilled over with the inflammable 
 gas. It was considered to be a 
 substance possessing even superior 
 properties to the vegetable tar for 
 the preservation of timber and 
 other perishable materials exposed 
 to the influences of the weather. 
 
 In the year 1665 a German 
 chemist proposed to distil coal for 
 the sole purpose of obtaining this 
 tar, and in 1781 the Earl of Dun- 
 donald took out a patent for col- 
 lecting the tar which appeared 
 during the formation of coke. Nei- 
 ther scheme answered. After a 
 few years' trial, coal-tar as a sub- 
 stitute for vegetable tar fell into 
 disuse. It was tried in the navy, 
 and was found to give the timber a 
 considerable degree of hardness, 
 but not of durability. Its smell is 
 extremely offensive ; and since that 
 time it has been used only in 
 places where that is of little conse- 
 quence. The exposed part of the" 
 machinery of a gas establishment 
 may be protected by being coated 
 with coal-tar. 
 
 Gasket, plaited cord fastened to the 
 sail-yards of a ship, and used to 
 furl or tie up a sail firmly to the 
 yard, byVrapping it round both six 
 or seven times, the turns being at 
 a competent distance from each 
 other. 
 
 Catchers, the after-leavings of tin. 
 
 Gate-house, or park entrance, a struc- 
 ture designed rather to produce an 
 agreeable and picturesque effect, 
 than to accord with any fixed rules 
 or customs of art : such, indeed, 
 was the practice towards the latter 
 end of the sixteenth century, when 
 it would appear, that most men 
 wished to display their taste and 
 learning in architecture. The gate- 
 house also forms an entrance to a 
 private mansion, to any public, 
 municipal, or collegiate building, 
 
 209 
 
 or to a palace, etc. In the early 
 English architecture, gate-houses, 
 now sometimes called Lodges, were 
 large and imposing structures, of 
 great elegance. 
 
 Gates and doors are generally, whe- 
 ther arched or square, twice their 
 breadth in height. The former 
 may be ornamented with columns, 
 pilasters, entablatures, pediments, 
 rustics, imposts, archivolts, etc. ; 
 the latter with architraves round 
 the sides and top of the opening, 
 and crowned with a frieze and cor- 
 nice. The cornice in this case is 
 very frequently supported with a 
 console on each side. Columns, 
 pilasters, and other ornaments are 
 also sometimes employed in the 
 decoration of doors. 
 
 Inside doors should not be nar- 
 rower than 2 feet 9 inches, nor is 
 it needful that they exceed 6 feet 
 in height ; entrance doors, 3 feet 
 6 inches to 6 feet 6 inches broad 
 in private dwellings : but in public 
 buildings, where crowds assemble, 
 they must be considerably enlarged. 
 The smallest width for agate should 
 be 8 feet 6 inches. 
 
 As some general rule for the pro- 
 portion of the architraves of com- 
 mon dressings to doors may be 
 useful, the following directions may 
 be safely followed : Supposing the 
 height of the aperture to represent 
 the height of a column ; then, if an 
 architrave, frieze, and cornice, or 
 the first only, be desired, take them 
 in the proportion that would serve 
 for the order itself, and return the 
 architrave down the sides of the 
 door. The whole entablature over 
 a square-headed door should never 
 exceed one-third the height of such 
 aperture. 
 
 Gauge (pronounced gage], a measure 
 by which the capacity or contents 
 of a cask or vessel may be ascer- 
 tained. Gauging is a term used in 
 mensuration, and applied by engi- 
 neers in their several operations. 
 The gauge, as applied to railways, 
 became a familiar term during the 
 
GAU 
 
 GERMAN SCHOOL OF PAINTING. 
 
 GEO 
 
 antagonistic discussions respecting j 
 the proper distance between the 
 lines of rail ; and the battle of the 
 gauges, which raged fiercely and ex- 
 pensively, ended, like many similar 
 contentions, in both parties spend- 
 ing enormous sums of money, with- 
 out the result of victory on either 
 side. 
 
 Gauge, a mixture of fine stuff and 
 plaster, or putty and plaster, or 
 coarse stuff and plaster ; used in 
 finishing the best ceilings and for 
 mouldings, and sometimes for set- 
 ting walls. 
 
 Gauge-cocks, two or three small cocks 
 fixed in front of the boiler of a steam- 
 engine, for the purpose of ascer- 
 taining the height of the water. 
 
 Gauge-glass, in locomotive engines, a 
 strong glass tube, connected with 
 the boiler by two cocks attached 
 to the gauge-cock pedestal. The 
 water is admitted to this tube by 
 the lower cock, the steam by the 
 upper cock. It thus becomes an 
 index to what is going on inside 
 the boiler, exhibiting the height 
 or agitation of the water in it. A 
 small cock is placed below the 
 glass for blowing out any sediment 
 which may be deposited in it. 
 
 Gauge-lamp, in locomotive engines, 
 a small lamp placed beside the 
 gauge-glass at night, that the state 
 of the water in the boiler may be 
 seen by the engine-man. 
 
 Gauntlet, in heraldry, an iron glove : 
 in challenges, the gauntlet was 
 thrown down in defiance. 
 
 Gear, furniture, dress, harness : the 
 term is also applied to the several 
 working parts of a locomotive 
 steam-engine. 
 
 Generating surface, the heating sur- 
 face of a boiler, or that on which 
 heat is applied to generate steam. 
 
 Gentese, in early English architecture, 
 cusps or featherings in the arch of 
 a doorway. 
 
 Geodesy, the art of measuring and 
 surveying of land. 
 
 Geometry, the science of quantity, 
 extension, or magnitude. 
 
 210 
 
 Geoscopy, a knowledge of the diffe- 
 rent kinds of earth. 
 
 German School of Painting. In early 
 times, a school of painting can 
 hardly be said to have existed in 
 Germany : it was merely a suc- 
 cession of single artists, who de- 
 rived their manner from different 
 sources of originality and imitation. 
 There were some German painters 
 of eminence when the art, emerg- 
 ing from its barbarous state, first 
 began to be cultivated in Europe; 
 but as they were totally unac- 
 quainted with the ancients, and had 
 scarcely access to the works of their 
 contemporaries in Italy, they copied 
 Nature alone, with the exception 
 of somewhat of that stiffness which 
 forms the Gothic manner. This 
 is by no means the case with their 
 successors, some of whom were edu- 
 cated in Flanders, and others in 
 Italy. But if Mengs or Dietrich 
 were comprehended in this school, 
 there would be nothing peculiar to 
 its manner discovered in their 
 works. Albert Durer was the first 
 German who corrected the bad 
 taste of his countrymen : he ex- 
 celled in engraving as well as in 
 painting ; his genius was fertile, his 
 compositions varied, his thoughts 
 ingenious, and his colours brilliant. 
 His works, though numerous, were 
 finished with great exactness. For 
 an account of this great man and 
 his productions, see the ' Works of 
 Divers Ancient Masters,' in two 
 vols. folio, 1846. 
 
 Geology (a treatise or discourse on 
 the earth) " is a term which admits 
 of a very wide interpretation, and 
 naturally suggests to the mind in- 
 quiries, 1st, into the formation 
 and original condition of the earth ; 
 2ndly, into the successive modifica- 
 tions which it has undergone, and 
 the agencies by which they have 
 been effected ; and Srdly, into its 
 present condition, and the agencies 
 by which changes in that condition 
 aje still effected. The first object 
 of the geologist is to establish, on 
 
GIB 
 
 GIRDERS. 
 
 GIR 
 
 the principles of inductive reason- 
 ing, the science as it depends on 
 each of these inquiries, and then to 
 apply it to the practical purposes 
 of life. It may be premised that a 
 science is practicably valuable just 
 in proportion as its facts have been 
 discovered, and its laws established 
 and studied ; for so long as we are 
 uncertain whether a known result 
 has proceeded from a definite cause, 
 we are unable to apply the fact or 
 circumstance to the elucidation of 
 other facts or circumstances ; and 
 so long as we are unacquainted 
 with the properties of any sub- 
 stance under our examination, we 
 cannot declare with certainty what 
 share it may have had in the phe- 
 nomena we have observed. This 
 may be illustrated by a reference 
 to gunpowder. Its explosive qua- 
 lity is the result of its composition, 
 and we can only depend upon the 
 results when we know that the 
 compound has been accurately 
 formed : to ensure, therefore, cer- 
 tainty in the operations depending 
 on it, we must take care that a 
 proper standard of composition has 
 been adhered to. In a similar man- 
 ner we can only apply geology as a 
 practical science when we have as- 
 certained and made ourselves fami- 
 liar with those facts which prove 
 the first principles on which it has 
 been founded to be correct and 
 stable." See Col. Portlock's work 
 in the Rudimentary Series, vol. 3. 
 
 Gib and key, the fixed wedge and the 
 driving wedge for tightening the 
 strap which holds the brasses at 
 the end of a connecting-rod in 
 steam machinery. 
 
 Gibbons (Grinling), the great carver. 
 The time and place of his birth is 
 unknown: he died 1721. 
 
 Gimlet, a piece of steel of a cylin- 
 drical form, having a transverse 
 handle at the upper end, and at the 
 other, a worm or screw, and a cy- 
 lindric cavity, called the cup, above 
 the screw, forming, in its trans- 
 verse section, a crescent. Its use 
 
 211 
 
 is to bore small holes : the screw 
 draws it forward in the wood, in the 
 act of boring, while it is turned 
 round by the handle: the angle 
 formed by the exterior and interior 
 cylinders cuts the fibres across, 
 and the cup contains the core of 
 wood so cut : the gimlet is turned 
 round by the application of the 
 fingers, on alternate sides of the 
 wooden lever at the top. 
 
 Gin, a machine, a pump worked by 
 wheels. 
 
 Giocondo (John) was born at Verona. 
 About the middle of the 1 5th cen- 
 tury he became a Dominican, and 
 acquired great reputation in the 
 sciences, the arts, the knowledge 
 of ancient monuments and archi- 
 tecture. He was called into France 
 by Louis XII., and constructed at 
 Paris the Pont-au-Change and the 
 Pont St. Michel. He also con- 
 structed other important works 
 in Italy and other countries. He 
 died at an advanced age in 1530. 
 
 Giotto built the exquisitely slender 
 tower of Florence in the 1 3th cen- 
 tury in emulation of the stupendous 
 spires which at that era were erec- 
 ted in Germany and the Low Coun- 
 tries. In Italy not a single spire 
 is now seen. 
 
 Giotto of the Florentine School. 
 Painting in his hands became so 
 elegant, that none of his school nor 
 of any other, till the time of Ma- 
 saccio, surpassed or even equalled 
 him, at least in gracefulness of 
 manner. Giotto was born in the 
 country, and was bred a shepherd. 
 
 Girders, the longitudinal beams in a 
 floor. Girders are the chief sup- 
 port of a framed floor : their depth 
 is often limited by the size of the 
 timber, but not always so ; there- 
 fore the method of findingthe s 'ant- 
 ling may be divided into more than 
 in one case. Girders of wrought 
 and cast iron are now extens vely 
 used in the construction of bridges, 
 to girt railroads, canals, etc , and 
 many of them are of considerable 
 span. 
 
GLA 
 
 GLUE. 
 
 GOD 
 
 Gland,the pressing piece of a stuffing; 
 box of a steam-engine. 
 
 Glass : this artificial transparent sub- 
 stance was introduced very early. 
 Hollinshed says, an Englishman 
 named Benedict Biscop, who had 
 taken upon him the habit of a 
 monk in Italy, came here with the 
 Archbishop of Rome, in the year 
 670, and brought painters, gla- 
 ziers, and other such curious crafts- 
 men into England for the first 
 time. 
 
 Glasses superseded small drinking- 
 bowls; they were of Venetian 
 manufacture, and probably first 
 brought here in the 16th century. 
 Earlier they do not appear to have 
 been used in England ; nor to have 
 come into much fashion till the 
 time of Elizabeth. 
 
 Glass water-gauge. See Gauge-glass. 
 
 Glazing, the art of fixing glass to the 
 sashes of windows, casements, etc., 
 for the purpose of admitting the 
 light of day ; anciently applied 
 to the affixing to windows deco- 
 rative, stained, and painted glass. 
 A great many beautiful examples 
 exist in this and other countries, 
 of early designs, and of examples 
 in the cinque-cento style : for the 
 latter, see ' Divers Works of Early 
 Masters,' 2 vols. folio, 1846. 
 
 Glazing is also a term applied to the 
 finishing of a drawing with some 
 thin, transparent, and glossy tint, 
 through which the first colours 
 appear, and are heightened in their 
 effect. 
 
 Glebe, turf, soil ; land possessed as 
 part of the revenue of an ecclesias- 
 tical benefice. 
 
 Glist, a shining black or brown mine- 
 ral, of an iron cast. 
 
 Glossocomon, a machine composed of 
 several dented wheels with pinions, 
 and used for raising great weights. 
 
 Glue, a tenacious viscid matter, which 
 is used as a cement by carpenters, 
 joiners, etc. Glues are found to 
 differ very much from each other 
 in their consistence, colour, taste, 
 smell, arid solubility. Some will 
 
 dissolve in cold water, by agitation ; 
 while others are soluble only at the 
 point of ebullition. The best glue 
 is generally admitted to be trans- 
 parent, and of a brown-yellow co- 
 lour, without either taste or smell. 
 It is perfectly soluble in water, 
 forming a viscous fluid, which when 
 dry preserves both its tenacity and 
 transparency in every part, and 
 has solidity, colour, and viscidity, 
 in proportion to the age and the 
 strength of the animal from which 
 it is produced. To distinguish 
 good glue from bad, it is necessary 
 to hold it between the eye and the 
 light ; and if it appears of a strong 
 dark brown colour, and free from 
 cloudy or black spots, it may be 
 pronounced to be good. The best 
 glue may likewise be known by 
 immersing it in cold water for 
 three or four days, and if it swells 
 powerfully without melting, and 
 afterwards regains its former di- 
 mensions and properties by being 
 dried, the article is of the best 
 quality. 
 
 A small portion of finely levi- 
 gated chalk is sometimes added to 
 the common solution of glue in 
 water, to strengthen it and fit it for 
 standing the weather. 
 
 A glue that will resist both fire 
 and water may be prepared by 
 mixing a handful of quicklime with 
 four ounces of" linseed-oil, thorough- 
 ly levigated, and then boiled to a 
 good thickness, and kept in the 
 shade, on tin plates, to dry. It 
 may be rendered fit for use by 
 boiling it over a fire in the ordi- 
 nary manner. 
 
 Glyphs, perpendicular flutings or 
 channels u>ed in the Doric frieze. 
 
 Gnomon, in dialling, is the style, pin, 
 or cock of a dial, the shadow 
 whereof points out the hours. 
 
 Goblets, stones ; a measure or quan- 
 tity, so called in the time of Ed- 
 ward III. 
 
 God the Father (in the Table of 
 Symbols of the early ages) is in- 
 dicated by a hand issuing from the 
 
GOL 
 
 GOVERNOR. 
 
 GOV 
 
 symbol of heaven, Ezek. ii. 9, viii. 
 3. God the Son, by a monogram 
 and by the cross (the symbol of 
 salvation); by a rock, 1 Cor. x. 4, 
 Exod. xvii. 6 ; by a lamb, Isaiah 
 Ivii. 7, frequently with a glory and 
 carrying a cross ; by a pelican, 
 Psalm cii. 6 ; by a vine, John xv. 1 ; 
 by a lamp or candle, as light of 
 the world, John ix. 5 ; by the pis- 
 cis, a vesica piscis, a glory, shaped 
 like a fish. God the Holy Ghost, 
 by the dove, with usually an olive 
 branch ; by water, either from the 
 beak of the dove, or from a vase, 
 John iv. 14 ; by a lamp or candle- 
 stick, seven of which rang-ed to the 
 right and left of the altar, to sig- 
 nify the gifts of the Spirit, Rev. i. 2, 
 iv. 5. 
 
 Gola, the Italian term for cyma. 
 
 Gold, a well-known valuable metal 
 found in many parts of the world, 
 but the greatest quantity was for- 
 merly obtained from the coast of 
 Guinea. The produce of California 
 remains to be determined. Gold 
 seems to be the most simple of all 
 substances. It is spoken of in 
 Scripture, and the use of it among 
 the ancient Hebrews, in its native 
 and mixed state, and for the same 
 purposes as at present, was very 
 common. The ark of the covenant 
 was overlaid with pure gold; the 
 mercy seat, the vessels and utensils 
 belonging to the tabernacle, and 
 those also of the House of the 
 Lord, as well as the drinking- 
 vessels of Solomon, were formed 
 of this metal. 
 
 Gold occurs, in the metallic state, 
 nixed with several metals, but 
 niore commonly with silver and 
 copper, and sometimes pure. 
 
 Gollen sulphur of antimony, golden 
 ydlow, is the hydro-sulphuret of 
 ar.iirnony, of an orange colour, 
 which is destroyed by the action of 
 strong light. It is a bad dryer in 
 oil, injurious to many colours, and 
 in no respect an eligible pigment 
 either in oil or water. 
 
 Gold purple, or Cassius 1 s purple preci- 
 
 213 
 
 pitate, the compound oxide which 
 is precipitated upon mixing the 
 solutions of gold and tin. It is not 
 a bright, but a rich and powerful 
 colour, of great durability, varying 
 in degrees of transparency, and in 
 hue from deep crimson to a mur- 
 rey or dark purple : it is princi- 
 pally used in miniature painting, 
 and may well be employed in ena- 
 mel painting. 
 
 Gondola, a Venetian barge much or- 
 namented, used in the canals of 
 Venice for the convenience of the 
 inhabitants: the common dimen- 
 sions are 30 feet by 4 feet : each 
 end is terminated by a very sharp 
 point, which is raised perpendicu- 
 larly to the full height of a man. 
 
 Goniometer, an instrument for mea- 
 suring angles and crystals. 
 
 Gossan, an imperfect iron ore, com- 
 monly of a tender rotten substance, 
 and of a red or rusty iron colour. 
 
 Gothic Architecture, usually so called. 
 Both Mr. Britton and Mr. Pugin 
 have treated of it by the name 
 of ' Christian Architecture.' It had 
 its rise from the Romanesque: this 
 took its origin from Roman remains 
 at the declension of that empire. 
 It became Saxon, then Norman, 
 and varied in its character with 
 the maturity of years. It was Early 
 English, Perpendicular, Decorated, 
 Flamboyant, etc., till it lost its ec- 
 clesiastical and monastic character 
 in the Domestic, which prevailed 
 in the Tudor style (Renaissance), 
 followed by the Elizabethan, etc. 
 
 Gouge, in carpentry, an instrument 
 like a round hollow chisel. 
 
 Governor, the apparatus for regulating 
 the supply of steam to the cylinder 
 so as to give a constant velocity to 
 the engine. It consists of two balls 
 suspended from a vertical spindle, 
 and revolving with it : the suspend- 
 ing rods are connected by arms to 
 a sliding-piece which fits the spindle 
 and acts upon a lever attached to a 
 throttle-valve in the steam-pipe : 
 the balls rise by the centrifugal 
 force as the velocity increases, and 
 
GOV 
 
 GOVERNOR. 
 
 GRA 
 
 close the valve : when the velocity 
 diminishes, the balls fall, and open 
 the valve. 
 
 Governor, a contrivance for equalizing 
 the motion of mills and machinery, 
 as well as being used as above de- 
 scribed. 
 
 Governor balls, the solid metal balls 
 fixed on the ends of the suspending 
 rods of the governor. 
 
 Governor (gas). The governor is a 
 machine for regulating and equali- 
 zing the flow of gas from the gaso- 
 meters to the street-mains, and is 
 much more perfect in its action 
 than any slide-valve applied for 
 that purpose requiring attendance. 
 Its use is nowhere sufficiently ap- 
 preciated. Had it been a compli- 
 cated piece of machinery, or ex- 
 pensive in its first cost and after- 
 application, objections to its adop- 
 tion would not have been surprising, 
 but it is perfectly simple, its ac- 
 tion is certain and unvarying, and 
 its first cost inconsiderable. 
 
 The velocity of gas in the mains 
 and pipes of supply is, in the first 
 instance, as various as there are 
 differences in their altitudes and 
 extent. A main at one place will 
 furnish, with a certain pressure of 
 gas, a flame one inch high ; while 
 at a different altitude it will furnish 
 a flame double that height. If, 
 again, in the direction of the main 
 there are many bends, angles, or 
 contractions in its diameter, the 
 velocity of the gas through it will 
 vary considerably more than if it 
 were direct and uniform. If the 
 pipe be of any great length, and of 
 uniform bore, but unequally fur- 
 nished with branches, the burners 
 will be unequally supplied with gas : 
 those which are near its head will 
 be supplied with a fuller stream of 
 gas than those which are situated 
 towards its termination. 
 
 Independently of these differ- 
 ences, arising from diversity of 
 local positions, there will always be 
 one great variation in the velocity 
 of the gas, occasioned by the va- 
 
 214 
 
 riety of periods during which lights 
 are required by different consumers 
 supplied from the same main or 
 system of pipes: for example, when 
 a certain number of burners is to 
 be supplied, and it happens that 
 one-half are shut off sooner than 
 the rest, the velocity of the gas in 
 the mains will be materially in- 
 creased, and the remaining lamps 
 should be turned down ; but many 
 would not be reduced, and much 
 gas would be lost. 
 
 Goivan, decomposed granite; but the 
 term is sometimes applied to the 
 solid rock. 
 
 Gozzan, oxide of iron and quartz. 
 
 Grace is taken for beauty, graceful 
 form or agreeableness of person ; 
 for form, friendship, and kindness; 
 for certain gifts of God, which He 
 bestows freely, when, where, and 
 on whom He pleases : such are the 
 gifts of miracles, prophecy, lan- 
 guage, etc. 
 
 Grace principally consists in the turn 
 that a painter gives to his objects, 
 to render them agreeable, even 
 those that are inanimate. It is 
 more seldom found in the face than 
 in the manner; for our manner is 
 produced every moment, and can 
 create surprise. A woman can be 
 beautiful but one way, yet she can 
 be graceful a thousand. Grace is 
 neither found in constrained nor in 
 affected manners, but in a certain 
 freedom and ease between two ex- 
 tremes. 
 
 Gradation, in painting and drawing, 
 implies the gradual receding of 
 objects into the remote distance, 
 by a proper strength or due dimi- 
 nution of light, shade, and colour, 
 according to their different dis- 
 tances, the quantity of light which 
 shines upon them, and the medium 
 of air through which they are seen. 
 
 Gradient, a deviation from a level 
 surface to an inclined plane. 
 
 Graduation, the division of philo- 
 sophical instruments into degrees 
 and other minute parts. 
 
 Grain tin, the finest tin, smelted with 
 
GRA 
 
 GRAVITY. 
 
 GRE 
 
 charcoal ; also the ore of very rich 
 tin sometimes found in the form of 
 grains or pebbles. 
 
 Grange, a monastic farming establish- 
 ment: in ancient times it was com- 
 mon to attach farm-houses and 
 granaries to the estates of religious 
 institutions. 
 
 Granite, a natural stone of great 
 strength, hardness, and durability ; 
 much used in building: it is a 
 primary and unstratified rock, con- 
 sisting of quartz, mica, and felspar, 
 each crystallized and cohering, but 
 without any base or cement. 
 
 Grapnel, in navigation, a sort of small 
 anchor with four or five flukes or 
 claws, commonly used for boats 
 and small vessels. 
 
 Graunge or Grange, a granary or 
 farm belonging to a religious house. 
 (Chaucer.) 
 
 Gravel, a geological term applied to 
 those sabulous soils, or assemblages 
 of worn and rounded stones, which 
 are found scattered on the surface 
 of the earth. 
 
 Graver, the burin of an engraver ; a 
 square piece of steel fixed in a 
 handle, and bevelled diagonally at 
 the end : an instrument used for 
 turning iron, after it has been 
 roughed out by the ' heel tool,' is 
 so called. 
 
 Gravity is that power or force which 
 causes bodies to approach each 
 other. This universal principle, 
 which pervades the whole system 
 of nature, may be enunciated as 
 follows : the mutual tendency of 
 two bodies towards each other in- 
 creases in the same proportion as 
 their masses are increased, and the 
 square of theirdistanceisdecreased; 
 and it decreases in proportion as 
 their masses are decreased, and as 
 the square of their distance is in- 
 creased. 
 
 Gravity is also the force wherewith a 
 body endeavours to descend to- 
 wards the centre of the earth : this 
 is called absolute gravity when the 
 body tends downwards in free space, 
 and relative gravity is the force it 
 
 215 
 
 endeavours to descend with in a 
 fluid. Terrestrial gravity is that 
 force by which bodies are urged 
 towards the centre of the earth, 
 and it is measured by the velocity 
 generated in a second of time. Ex- 
 periments show that a falling body 
 describes 16^ feet in one second, 
 and it has then acquired a velocity 
 of 32 feet, which is therefore the 
 true measure of the force of gravity. 
 
 Gray colour is the third and last, 
 being the nearest in relation of co- 
 lour to black. In its common ac- 
 ceptation, gray denotes a class of 
 cool cinerous colours, faint in hue ; 
 whence we have blue-grays, olive- 
 grays, green -grays, purple- grays, 
 and grays of all hues, in which 
 blue predominates ; but no yellow 
 or red grays, the predominance of 
 such hues carrying the compounds 
 into the classes of brown and mor- 
 rone. 
 
 Graywacke, a coarse slate ; in geo- 
 logy, a secondary rock. 
 
 Grease-cock, a short pipe fixed in the 
 cylinder cover of a steam-engine, 
 with two stop-cocks inserted at a 
 short distance apart, and a funnel at 
 the top for holding tallow. When 
 the upper cock is opened, the tallow 
 falls into the intermediate space ; 
 the cock is then closed, and the 
 lower one opened for the melted 
 grease to enter the cylinder, and 
 lubricate the piston without allow- 
 ing the steam to escape. 
 
 Great Circle sailing, the steering of a 
 ship in the arch of a great circle 
 of the sphere. The nearest course 
 between two places. 
 
 Green Cloth, the compting-house of 
 the Kings' households. 
 
 Greenhouse, a garden-house for choice 
 flowers, etc. 
 
 Greenvtrditeris, the same in substance 
 as blue verditer, which is converted 
 into green by boiling it. 
 
 Green ebony wood, imported from the 
 West Indies, is used for round 
 rulers, turnery, marquetry-work, 
 etc.; it is also much used for dyeing, 
 and contains resinous matter. 
 
GRE 
 
 GREGORIAN CHANT. 
 
 GRE 
 
 Greenheart wood, from the West In- 
 dies, resembles cocoa wood in sife 
 and bark, and is used for turnery 
 and other works. 
 
 Grees, steps ; also a staircase. 
 
 Gregorian Chant: Cantus Gregoria- 
 nus, Cantus Firmus, Cantus Planus 
 or Plenus, in Latin ; Canto Firmo, 
 in Italian ; Plein Chant, in French ; 
 Plain Chant, in English ; and Choral, 
 in German. This species of music 
 is the most ancient of all, and is 
 still the only one properly adapted 
 to the ritual services of the Chris- 
 tian churches. 
 
 The Gregorian chant consists of 
 a few notes, on which the words 
 of the Liturgies are recited. The 
 earliest specimens in existence con- 
 sist of only one or two notes, and 
 were used by St. Ambrose, at Milan, 
 in the fourth century. The origin 
 of this chant is traced to the earlier 
 churches of Egypt, Thebes, Pales- 
 tine, Arabia, Phoenicia, Syria, etc., 
 from whence it was introduced into 
 the church of Constantinople by 
 St. John Chrysostom. St. Ambrose 
 is said to have brought it into use 
 in Milan, " after the custom of the 
 inhabitants of the East," and from 
 Milan it came to Rome " long be- 
 fore the time of St. Gregory." But 
 as, in the course of time, various 
 mutations had taken place, St. Gre- 
 gory, in order to reform and settle 
 the music fcr the church, made a 
 compilation of such as was fit for 
 its use, and formed the first ritual 
 book of music, or Roman Anti- 
 phonarium. From the order which 
 he gave it, and in consequence of 
 this work of Gregory being after- 
 wards established in the other (the 
 Western) churches, it received the 
 name Gregorian. We have very 
 little of the music ascribed to Gre- 
 gory himself, a specimen of which 
 is given by Mr. Spencer in his work 
 on the church modes, and is very 
 grand. A portion of the old Gre- 
 gorian chant is still used in our 
 cathedrals in the so-called ' into- 
 ning the service' by the minor 
 
 216 
 
 canons and also in the responses by 
 the choir, but in a very mutilated 
 form. But in the chanting of the 
 prose Psalms, it is almost entirely 
 abandoned ; the only specimen (and 
 that somewhat mutilated) being 
 the grand and well-known ' Tallis's 
 chant.' There is a remarkable 
 difference between the Gregorian 
 melodies for the Psalter and Can- 
 ticles (and which are called the 
 eight tones} and those of a more 
 modern date. No such thing as a 
 double chant exists in Gregorian 
 music, and the ' tones ' are formed 
 on one general law ; i. e. a ' tone ' 
 consists of one principal note, called 
 the Dominant, z.e.the predominant 
 or reciting note, upon which the 
 principal part of each half-verse is 
 chanted, the remainder being in- 
 flected in cadences of one or several 
 notes revolving (as it were) above 
 and below the dominant, or ter- 
 minating on the final of the mode ; 
 and it is a law that the reciting 
 parts are always (when the tone is 
 regular) on the same note, viz. the 
 dominant. There are very few 
 instances of any deviation from 
 this rule. In the modern system 
 there seems to be a total absence 
 of any rule of this sort, and the 
 cadences, both in the middle of the 
 verse and at the end, consist of a 
 greater number of notes, and these 
 of unequal value. Moreover, in the 
 Gregorian chant no attention is 
 paid to time; it is regulated entirely 
 by emphasis and syllabic quantity, 
 not by time and accent, as in mo- 
 dern chanting. On Sundays and 
 the greater festivals it is a rule to 
 commence the ' tone ' with a few 
 preliminary notes, called the into- 
 nation, which serve as in inchoa- 
 tion, or induction to the dominant, 
 or reciting note : on other occa- 
 sions, these initial notes are not 
 used. For specimens of the adap- 
 tation of these Gregorian tones or 
 chants to the canticles, etc., of the 
 English church, see the ' Hymnal/ 
 by Mr. Spencer. 
 
GRE 
 
 GROINS. 
 
 GRO 
 
 Gregorian music requires a no- 
 bler and more rigid harmony than 
 can be given in the modern system ; 
 and its effects in the divine offices, 
 when properly harmonized and 
 performed, are far superior to any 
 other kind of church music. 
 
 Greut, or Grit, a kind of fossil body, 
 consisting of sandy, rough, hard, 
 earthy particles. 
 
 Grey. See Gray. 
 
 Griddle, a large wire sieve, used in- 
 stead of a hurdle, for sifting and 
 sorting copper ore as it rises from 
 the mine. 
 
 Grimbald, an architect, supposed to 
 have introduced the style of ar- 
 chitecture usually called Saxon 
 into England. 
 
 Grindstone, a cylindrical stone, on 
 which, being turned round its axis, 
 edge-tools are sharpened by apply- 
 ing their edges to the convex sur- 
 face. 
 
 Gripe, the lower part of the knee of 
 the head that connects with the 
 foremost end of the keel of a vessel. 
 
 Grit, coarse sand ; rough hard par- 
 ticles of sandstone. 
 
 Groin, the angle formed by an inter- 
 section of vaults : most of the 
 vaulted ceilings of the buildings of 
 the middle ages were groined, and 
 therefore called groined ceilings. 
 During the early part of the Nor- 
 man style the groins were left pur- 
 posely plain, but afterwards they 
 were invariably covered with ribs. 
 
 Groins, in coast engineering. A groin 
 is a frame of wood-work, con- 
 structed across a beach, between 
 high and low water, perpendicular 
 to the general line of it, either to 
 retain the shingle already accumu- 
 lated, to recover it when lost, or to 
 accumulate more at any particular 
 point ; also to break and check the 
 action of the waves. 
 
 The component parts of a groin 
 are piles, planking, land-ties, land 
 tie-bars, blocks, tail-piles, and keys 
 and screw-bolts. 
 
 The length of a groin depends 
 on the extent, and the requisite 
 
 strength of its component parts on 
 the nature of the beach on which 
 it is to be constructed. Those at 
 Eastbourne, on the coast of Sussex, 
 of which the following is more 
 particularly a description, are from 
 150 to 250 feet in length, and the 
 beach at that place being very 
 rough, consisting of coarse heavy 
 shingle and large boulders, they 
 require to be composed of propor- 
 tionally strong materials to resist 
 its force. 
 
 The piles are from 12 to 25 feet 
 long, and 8 by 65 inches scantling, 
 shod with iron. 
 
 The planking is in lengths of 8, 
 12, and 16 feet, 1\ inches thick, 
 and with parallel edges. 
 
 The land-ties are of rough timber 
 from 20 to 25 feet long, and large 
 enough at the butt-end to receive 
 the bars. 
 
 The land tie-bars are 1 3 ft. 6 in. 
 long, and 12 by 5 in. scantling. 
 
 The land tie-bar blocks are about 
 2 feet long, and of the same scant- 
 ling as the piles. 
 
 The land-tie tail-keys are about 
 2 feet 6 inches long, and 6 by 2 
 inches scantling. 
 
 The above materials are of oak 
 or beech. 
 
 The screw-bolts are of inch round j 
 iron, 2 feet 9 inches and 2 feet I 
 1-^inch long, in equal proportions, j 
 
 The relative proportions of the 
 component parts are, four piles, one 
 land-tie with tail-piles and keys, 
 one land tie-bar with two blocks, 
 two long and two short bolts, about 
 180 square feet of planking, and 
 about 140 six-inch spikes for every 
 17 feet in length; and the expense 
 of a groin, constructed with mate- 
 rials of the above dimensions, may 
 be calculated at about 30 for the 
 same length. 
 
 GENERAL RULES OBSERVED IN 
 THE CONSTRUCTION. 
 
 When the object, in constructing 
 a groin, is to recover shingle, or 
 accumulate more, the first pile is 
 driven at the high -water mark of 
 
 217 
 
GRO 
 
 GROTESQUE. 
 
 GUI 
 
 neap-tides, leaving its top level with 
 that of spring-tides. The next & 
 driven at the point on the sands, 
 beyond the bottom of the shingle, 
 to which the groin is to extend, 
 leaving about 4 feet of it out of 
 the beach. 
 
 The tops of these two piles may 
 be taken for the general slope of 
 the groin, unless the beach should 
 be very steep, and much curved, in 
 which case it becomes necessary to 
 follow its curvature in some degree. 
 From the high-water mark of 
 neap-tides, the piles are carried 
 back nearly level to that of spring- 
 tides, and as much further as may 
 be considered necessary. 
 
 The piles are driven 4 feet asun- 
 der from centre to centre, and so 
 as to admit the planking between 
 them alternately, and they should 
 be sunk about two-thirds of their 
 length. 
 
 The longest piles are placed be- 
 tween the high -water mark of neap- 
 tides and the bottom of the shingle, 
 particularly from 20 to 40 feet 
 below the former point. 
 
 The planking is, if possible, car- 
 ried down to about two-thirds from 
 the tops of the piles, and kept pa- 
 rallel with them. 
 
 The land-ties are placed about 
 one-third from the top of the plank- 
 ing (supposing the latter to com- 
 mence from the tops of the piles), 
 and their tails are sunk to the level 
 of the bottom of the planking, or 
 as nearly so as possible. 
 Grotesque. This term, which is now 
 familiar among all the lovers of the 
 art of painting, was by the Italians 
 appropriated to that peculiar man- 
 ner of composition and invention 
 observed among the antique mo- 
 numental paintings which were 
 discovered in the subterraneous 
 chambers that had been decorated 
 in the times of the ancient Romans; 
 and as the Italians apply the word 
 Grotto to express every kind of 
 cave or grot, all paintings which 
 were in imitation of the antique 
 
 218 
 
 designs discovered in those cham- 
 bers, which for ages had been 
 covered with ruins, are grotesqued 
 or grotesque, which is now applied 
 to English subjects of a quaint and 
 anomalous character. 
 Grotesque, a name given to the light 
 and fanciful ornaments used for- 
 merly to characterize persons and 
 things. 
 Grotto, a natural or artificial cavern 
 
 or cave. 
 
 Grouan lode, any tin lode which 
 abounds with rough gravel or sand. 
 Ground-plate or ground-sill, the low- 
 est plate of a wooden building for 
 supporting the principal and other 
 posts. 
 
 Grounds, pieces of wood fixed to walls 
 and partitions, with their surfaces 
 flush with the plaster, to which the 
 facings or finishings are attached. 
 Ground table stones, the projecting 
 course of stones in a wall above the 
 plinth. 
 
 Ground-ways, large pieces of timber 
 laid across a ship or dock, and 
 upon which the blocks are placed. 
 Groundwork, in painting, that colour 
 or part on which all the images 
 are drawn. 
 
 Grouping is the combining or joining 
 objects in a picture for the satis- 
 faction of the eye, and also for its 
 repose ; and although a picture may 
 consist of different groups, yet 
 those groups of objects, managed 
 by the chiaro-oscuro, should all 
 tend to unity, and one only should 
 predominate. 
 
 Guag, Cornish. Tinners, holeinginto 
 a place which has been wrought 
 before, call it holeing in guag. 
 Gudgeon, the iron pins fixed in a 
 beam or wooden shaft for bearings. 
 Gudgeons, in ship-building, are eyes 
 driven into the stern-post, to hang 
 the rudder on. 
 
 Guide-blocks, pieces of metal with 
 parallel sides, fitted on the ends of 
 a cross-head of a steam-engine, to 
 slide in grooves in the side frames, 
 and keep the motion of the piston- 
 rod in a direct line. 
 
GUI 
 
 GUSSETS. 
 
 HAL 
 
 Guilloche, an ornament used in clas- 
 sical architecture, formed by two 
 or more intertwining bands. 
 
 Gulf of ore .- a lode which throws 
 up very great quantities of ore, and 
 proves lasting and good in depth, 
 is so called. 
 
 Gum wood, or blue gum wood, is the 
 produce of New South Wales, sent 
 over in large logs and planks, simi- 
 lar to dark Spanish mahogany : it is 
 used in ship-building, etc. 
 
 Gun-boats were first made in this 
 country with condensing engines, 
 but of late a few have been made 
 with non-condensing or high- 
 pressure engines, which latter kind 
 are found more convenient where 
 fresh supplies of fuel can be rea- 
 dily obtained. 
 
 Gundulf of Rochester, 1077-1107. 
 His works are seen at Rochester, 
 Canterbury, and Peterborough. 
 
 Gun-metal, a mixed metal, an alloy 
 of copper and tin. 
 
 Gunnies, in Cornish, a term applied 
 to breadth or width : single gun- 
 nies are 3 feet wide. 
 
 Gunter's chain, the chain in common 
 use for measuring land : the length 
 of the chain is 66 feet, or 22 yards, 
 or 4 poles of 5 yards each ; it 
 is divided into 100 links of 7'92 
 inches each. See Acre. 
 
 Gunwale, or gunnel, in ship-building, 
 the piece of timber which reaches 
 on either side of the ship from the 
 half-deck to the forecastle. The 
 plank that covers the heads of the 
 timbers between the fore and 
 main drifts. 
 
 Gussets, .as understood in mechanical 
 construction, are brackets or an- 
 gular pieces of iron, to strengthen, 
 to keep steady, and support a 
 structure. In the construction of 
 
 the rectangular covered openings 
 of the Britannia and Conway iron 
 bridges, gussets are used exten- 
 sively in the interior, consisting of 
 double triangular plates riveted to 
 the bottom and sides of the plates 
 of the bridge, as a series of brack- 
 ets (and at the top and either side 
 also), to aid to the strength and 
 durability of these extraordinary 
 works, and as a counter-effort to 
 the tendency of strain on the lower 
 sides to separate or open the joints, 
 and on the upper side to force 
 them closer together. 
 
 Gusto, a term used by the Italians, 
 signifying taste in the design of the 
 attitudes, good arrangement, and 
 composition of a picture. 
 
 Gutta, ornaments resembling drops, 
 placed in the epistylium of the 
 Doric order below the triglyphs. 
 They occur likewise in the under 
 face of the mutules in the Doric 
 corona. They are supposed to have 
 originated from the intention to 
 represent drops of water running 
 off the roof, adhered to the under 
 surface of the canterii or rafters of 
 early buildings. 
 
 Gybing, in navigation, the shifting of 
 any boom-sail from one side of the 
 mast to the other. 
 
 Gymnasium, a public building used 
 by the Greeks for the practice and 
 exercise of gymnastics, or mus- 
 cular development ; also a place, 
 according to Vitruvius, for amuse- 
 ments and scientific recreation. 
 
 Gynosceum, in Greek architecture, 
 the apartment of the females in the 
 interior of the house ; the nursery. 
 
 Gypsoplaste, a cast taken in plaster of 
 Paris or white lime. 
 
 Gypsum, sulphate of lime, called also 
 plaster of Paris. 
 
 H. 
 
 HADE OF VEINS is the mining-term 
 for that inclination which nearly 
 all veins have from a perpendicular 
 direction. Thus, a vein is said to 
 
 219 L 2 
 
 hade to the north when it inclines 
 further north. In Weardale, the 
 veins mostly hade to the south. 
 Half -bloom, a round mass of metal, 
 
HAL 
 
 HALF-TIMBERED HOUSES. 
 
 HAR 
 
 which comes out of the fining ^f 
 an iron work. 
 
 Half-pace, or Haute-pace, a raised 
 floor in a bay window. 
 
 Half-timbered houses : this mode of 
 constructing domestic buildings 
 was practised in England and on 
 the Continent during the reigns of 
 Henry VIII. and Elizabeth. It was 
 peculiarly of a picturesque charac- 
 ter ; the foundations and principal 
 supports were of stout timber, and 
 the interstices of the fronts were 
 filled with plaster. In many cases 
 the ornamental timber framing was 
 of a dark colour, which, with the 
 barge-board gable, gave the whole 
 an exceedingly interesting appear- 
 ance. There are yet remaining 
 some very fine examples in England, 
 particularly in the western and 
 north-western counties. 
 
 Half-timbers, in ship-building, those 
 timbers in the cant-bodies which 
 are answerable to the lower fut- 
 tocks in the square body. 
 
 Hall, the principal apartment in the 
 domestic houses of the middle ages ; 
 a place of assembly ; a spacious 
 building attached to inns of court. 
 
 Halliards, in navigation, the ropes or 
 tackles usually employed to hoist 
 or lower any sail on its respective 
 mast. 
 
 Holy-work folk, people who hold 
 land for repairing or defending a 
 church or tombs, on which account 
 they were freed from feudal and 
 military service. 
 
 IlaUyings, the hangings of a hall. 
 
 Halvans, in Cornish, the refuse ore. 
 
 Ham (Saxon), a house, home, farm, 
 or village. 
 
 Hamburg lake is a colour of great 
 power and depth ; rather purplish, 
 or inclining to crimson : it dries 
 with extreme difficulty, but differs 
 in no other essential quality from 
 other cochineal lakes. 
 
 Hamlet, a street or village, a dwell- 
 ing place. 
 
 Hammer-beams, horizontal pieces of 
 timber, frequently used in the roofs 
 of old English buildings, in pairs 
 
 220 
 
 on the opposite sides of the same 
 roof ; often used also in the prin- 
 cipals of Gothic roofs, to strengthen 
 the framing and to diminish the 
 lateral pressure that falls upon the 
 walls. 
 
 Hances, in architecture, ends of ellip- 
 tical arches, which are arcs of 
 smaller circles than the scheme or 
 middle part of the arch. 
 
 Hand-brace, a tool for boring, con- 
 sisting of a cranked spindle, at one 
 end of which a broad head or 
 breast-plate is attached by a swivel, 
 so that it may remain stationary 
 while the crank is turned ; at the 
 other end is a socket, into which a 
 drill can be fixed. 
 
 Hand-drilling machine,*, small drilling 
 machine turned by manual labour. 
 
 Hand-gear, in a locomotive engine, 
 the handles of the working gear, 
 placed conveniently to the foot- 
 plate so as to be within reach of 
 the engine-man when he requires 
 to use them for regulating the dif- 
 ferent parts of the engine. 
 
 Hand-hook, an instrument made by 
 smiths to twist square iron. 
 
 Hand-pump, in a locomotive engine, 
 the pump placed by the side of the 
 fire-box, to be worked by a hand- 
 lever when the engine has to stand 
 with steam up. 
 
 Hand-railing, in a locomotive engine, 
 the railing along the sides of the 
 engine, to protect persons passing 
 to the front of the engine for any 
 necessary purpose. 
 
 Hand-saw, a saw from 12 to 15 inches 
 in length, fixed in an iron frame, 
 with a handle at one end ; used for 
 cutting wood or metal. 
 
 Hand-screw, a jack, an instrument 
 for raising heavy timber. 
 
 Hand-spike, a wooden lever for mov- 
 ing heavy things. 
 
 Hand-vice, a small vice which is held 
 in the hand. 
 
 Harbourage, shelter, or entertainment. 
 " Crave harbourage within [your 
 city walls." Shakspeare. 
 
 Harmony is the general accordance of 
 the objects in a painting with one 
 
HAR 
 
 HEALTH OF TOWNS. 
 
 HEA 
 
 another, and their subordination to 
 the principal object ; so that all 
 unite to constitute a pleasing whole. 
 It is effected by a due combination 
 of lights and shades, by the union 
 and colour, or by such contrasts 
 as are sufficient to relieve the dis- 
 tant groups. 
 
 Harmony of colours. Lessons in 
 colouring have ever been given, not- 
 withstanding it is a part so princi- 
 pal in painting, that it has its rules 
 founded on science and reason. 
 Without such study, it is impos- 
 sible that youth can acquire a good 
 taste in colouring, or understand 
 harmony. 
 
 Harpinos, "pieces of oak which hold 
 the timbers of the fore-and-aft 
 cant-bodies till a ship is planked. 
 
 Hatches, the coverings for the hatch- 
 ways of a ship, made with ledges, 
 and laid with oak or deal, and 
 caulked. 
 
 Hatches, flood-gates in a river to stop 
 the current of the water. 
 
 Hatching is shadowing with a black- 
 lead pencil or pen : it is done either 
 in straight lines or zigzag strokes, 
 such as are seen in pencil draw- 
 ings, or in pencilled backgrounds. 
 It is used by engravers in etching. 
 
 Hatchways, places in the middle of 
 the decks of a vessel, for the con- 
 venience of lowering down goods. 
 
 Haul the wind, in navigation, to direct 
 the ship's course nearer to the 
 point of the compass from which 
 the wind blows. 
 
 Haunch of an arch, the part between 
 the vertex and the springing. 
 
 Hawker, a vessel built like a pink, 
 but masted and rigged like a hoy. 
 
 Haws, in Domesday Book, mansions 
 or dwelling-houses. 
 
 Hawse, in navigation, the situation of 
 the cables before the ship's stern 
 when she is moored with two an- 
 chors forward from the starboard 
 and larboard bow. 
 
 Hawse-pieces,. tlie timbers in the bow 
 of a ship whose sides are nearly 
 parallel to the middle line. 
 Hawthorn, a wood not much used, is 
 
 221 
 
 hard, and of a whitish colour, with 
 a tinge of yellow. 
 
 Hazel, a small underwood, which is 
 very elastic, used for turning, for 
 the handles of blacksmiths' chisels, 
 for the hoops of casks, etc. 
 
 Head-ledges, the thwartship pieces 
 which frame the hatch-ways or 
 ladder- ways of ships. 
 
 Head-stocks, the frames which sup- 
 port the centres of a lathe; viz. 
 the mandril-frame and the poppet- 
 head, or back centre frame. 
 
 Head- tin, a preparation of tin-ore to- 
 wards the fitting it for working 
 into metal. 
 
 Headers, in masonry, stones extend- 
 ing over the thickness of a wall ; 
 and in bricklaying, the bricks which 
 are laid lengthwise across the thick- 
 ness of the wall are called headers. 
 
 Heads, tiles which are laid at the 
 eaves of a house. 
 
 Healing, the covering a roof with 
 lead, tin, slates, etc. 
 
 Health of Towns, a phrase recently 
 coined to express the general pur- 
 pose of public sanatory measures. 
 These measures are based upon the 
 principles of animal physiology, but 
 had been recognized only in the 
 curative policy of the physician, 
 until the evils of their neglect were 
 traced by statistical inquiries into 
 the causes of disease ; and they are 
 therefore now properly regarded as 
 essential objects in the social eco- 
 nomy of life. 
 
 The human constitution is so 
 formed that its health depends on 
 an adequate supply of pure air, 
 water, and light. Every circum- 
 stance, therefore, which vitiates the 
 quality, or reduces the due quan- 
 tity, of these essentials, is injurious 
 to health, and demands amendment 
 or extinction. 
 
 Thus the efficient supply of pure 
 and attemperated air requires pro- 
 per drainage and ventilation, warm- 
 ing or cooling of all places in which 
 human beings live or congregate : 
 it also limits the minimum of size 
 for the healthy habitations of men. 
 
HEA 
 
 HEAT. 
 
 HEA 
 
 The plentiful supply of pure \va- 
 ter necessitates suitable provision 
 for obtaining and treating it, and 
 the proscription of all arrangements 
 which limit the service or injure 
 its purity. Equally important with 
 these conditions is the third one 
 enumerated, which suggests the ne- 
 cessity of so arranging and con- 
 structing streets and buildings, that 
 abundance of light may at all times 
 be admitted into them. 
 
 As measures auxiliary to these 
 objects, and of great importance in 
 the combined arrangements of so- 
 ciety, public exercising and plea- 
 sure grounds, baths and wash- 
 houses, cooking apparatus, medical 
 and remedial establishments, street 
 accommodations, etc., command 
 adoption, and, when adequately 
 carried out, will tend to complete 
 the physical requisites of the health 
 of towns. 
 
 Heat, in the ordinary application of 
 the word, signifies, or rather im- 
 plies, the sensation experienced 
 upon touching a body hotter, or 
 of a higher temperature, than the 
 part or parts which we bring into 
 contact with it : in another sense, 
 it is used to express the cause of 
 that sensation. To avoid any am- 
 biguity that may arise from this 
 double use of the same expression, 
 it is usual and proper to employ 
 the word caloric to signify the 
 principle or cause of the sensation 
 of heat. On touching a hot body, 
 caloric passes from it, and excites 
 the feeling of warmth : when we 
 touch a body having a lower tem- 
 perature than our hand, caloric 
 passes from the hand to it, and 
 thus arises the sensation of cold. 
 
 Caloric is usually treated of as if 
 it were a material substance ; but, 
 like light and electricity, its true 
 nature has yet to be determined. 
 
 COMMUNICATION OF CALORIC. 
 
 Caloric passes through different 
 bodies with different degrees of ve- 
 locity. This has led to the division 
 of bodies into conductors and non- 
 222 
 
 conductors of caloric : the former 
 includes such bodies as metals, 
 which allow caloric to pass freely 
 through their substance ; and the 
 latter comprises those that do not 
 give an easy passage to it, such as 
 stones, glass, wood, charcoal, etc. 
 Table of the relative conducting 
 
 power of different bodies. 
 Gold . . . 1000 
 Platinum . . .981 
 Silver . . .973 
 Copper . . .898 
 Iron . . .374 
 Zinc . . . 363 
 Tin . . . . 304 
 Lead ... 180 
 Marble ... 24 
 Porcelain. . . 12-2 
 Fire-brick -. . 11 
 Fire-clay . . . 11 '4 
 With Water as the standard. 
 Water . . . 10 
 Pine ... 39 
 Lime ... 39 
 Oak. . . . 33 
 Elm ... 32 
 Ash. . . . 31 
 Apple ... 28 
 Ebony ... 22 
 Relative conducting power of dif- 
 ferent substances compared wit ft 
 each other. 
 
 Hares' fur . .1-315 
 Eider-down . . 1'305 
 Beavers' fur . . 1'296 
 Raw silk . . . 1-284 
 Wool . . . 1-118 
 Lamp-black . . 1-117 
 Cotton . . . 1-046 
 Lint . . . 1-032 
 
 Charcoal . . . -937 
 Ashes (wood) . . -927 
 Sewing silk . . -917 
 Air ... -576 
 
 Relative conducting power of fluids. 
 Mercury . . . I'OOO 
 Water . . . -357 
 Proof Spirit . . '312 
 Alcohol (pure) . . '232 
 
 RADIATION OF CALORIC. 
 
 W'hen heated bodies are exposed 
 to the air, they lose portions of 
 
HEA 
 
 HEIGHTS AND DISTANCES. 
 
 HE I 
 
 their heat, by projection in right 
 lines into space, from all parts of 
 their surface. 
 
 Bodies which radiate heat best, 
 absorb it best. 
 
 Radiation is affected by the na- 
 ture of the surface of the body : 
 thus black and rough surfaces ra- 
 diate and absorb more heat than 
 light and polished surfaces. 
 Table of the radiating power of 
 
 different bodies. 
 Water . . .100 
 Lamp-black . . 100 
 Writing-paper . .100 
 Glass ... 90 
 Indian ink . . 88 
 Bright lead . . 19 
 Silver ... 12 
 Blackened tin . . 100 
 Clean do. . . 12 
 Scraped do. . . 16 
 Ice . . . . 85 
 Mercury ... 20 
 Polished iron . . 15 
 Copper . . . 12 
 Professor Leslie has proved, by a 
 variety of experiments, that the 
 heat which is propagated by radi- 
 ation from different bodies varies 
 with the nature of their external 
 surfaces ; the quantity which flows 
 in a given time from a body with a 
 polished surface being much less 
 than would flow from the same 
 body with a rough surface. It 
 therefore follows that the external 
 surfaces of the steam-pipes of steam- 
 engines and steam-cylinders should 
 be as smooth as possible, and should 
 be covered with any body which is 
 a bad conductor of heat. 
 Heaven (in the Table of Symbols of 
 the early ages) is symbolized by 
 the segment of a circle, sometimes 
 of blue or of the three colours of 
 the rainbow ; the Universe, by a 
 globe of blue. 
 
 Heckler (Jean Geo.), born in 1628, 
 became in 1654 architect of the 
 cathedral of Strasburg, and died 
 in 1669. 
 
 Heel tool, a tool used by turners for 
 roughing out a piece of iron, or 
 
 223 
 
 turning it to somewhat near the 
 intended size : it has a very acute 
 cutting edge and an angular base 
 or heel. 
 
 Height of columns. The height of a 
 column is measured by its diameter 
 immediately above the base. 
 
 Diameters high. 
 
 The Tuscan column . 7 
 The Ionic ... 9 
 Corinthian and Composite 10 
 In the above heights are included 
 the capitals and bases, which are 
 esteemed parts of the columns with 
 which they are used. 
 Heights and Distances. Trigonometry 
 receives its principal practical ap- 
 plication in the operations of sur- 
 veying, and measuring heights and 
 distances ; as, however, the methods 
 of its application (depending on the 
 peculiar circumstances of each case) 
 are exceedingly various, no general 
 rules can be specified. 
 
 The instruments employed to 
 measure angles are quadrants, sex- 
 tants, theodolites, etc., the use of 
 either of which may be sooner 
 learned from an examination of the 
 instruments themselves than from 
 any description independently of 
 them. For military men and for 
 civil engineers, a good pocket sex- 
 tant and an accurate micrometer 
 (such as Cavallo's), attached to a 
 telescope, are highly useful. For 
 measuring small distances, as bases, 
 50-feet and 100-feet chains and a 
 portable box of graduated tape will 
 be necessary. 
 
 For the purposes of surveying, it 
 is usual to employ a chain 66 feet 
 in length, subdivided into 100 links, 
 each 7'92 inches : the reason for 
 using a chain of this length is, that 
 ten of such square chains are equal 
 to an acre, and therefore the acre- 
 age of the several divisions of an 
 estate is found with much greater 
 facility when measured in chains 
 and links, than when the measure- 
 ments are taken in feet. 
 Heil, to cover, to tile. Wat Tyler 
 was called Wat the Heiler. 
 
HEL 
 
 HERALDRY. 
 
 HIN 
 
 Helix, the small volute under the* 
 abacus of a Corinthian capital. 
 
 Helix, anything of a spiral form, whe- 
 ther in one plane, as the spiral curve, 
 or in different planes, as the screw. 
 
 Hemlock spruce forms a large pro- 
 portion of the evergreen forests of 
 New Brunswick, and is abundantly 
 multiplied in every favourable si- 
 tuation. The wood of the hemlock 
 spruce is firmer than that of the 
 white pine ; although coarser, 
 grained, it gives better hold to 
 nails, and offers more resistance 
 to the impression of other bodies. 
 
 Hengin, a prison, or house of cor- 
 rection. 
 
 Heptagon, in geometry, a figure with 
 seven sides or angles. 
 
 Heraldry is a science intimately con- 
 nected with the early history of 
 Europe, its chivalry, its conquests, 
 and the bearing of arms : it teaches 
 how to blazon or explain in proper 
 terms all that belongs to arms ; 
 and how to marshal or dispose 
 with extreme punctualness divers 
 arms on a field. It is in its archae- 
 ology and in precedent indisputable. 
 It teaches whatever relates to the 
 marshalling of solemn processions 
 and other public ceremonies, at co- 
 ronations, installations of Knights of 
 the Garter, Knights Grand Cross of 
 the Bath, Knights Companions, etc.; 
 at the creation of peers, nuptials, 
 christenings of princes, funerals, etc. 
 It is, in fact, au important science, 
 particularly in English history, in 
 tracing the narrative of the families 
 of the nobility and commoners, 
 their holdings, their distinguishing 
 qualifications, in arms, in literature, 
 and in the arts. 
 
 Hermce, statues of which only the 
 head is carved, and sometimes a 
 portion of the bust : square or cu- 
 bical figures of the god Mercury, 
 without legs and arms, anciently 
 placed by the Greeks and Romans 
 at their cross-ways. 
 
 Herring-bone work, masonry in which 
 the stones are laid aslant instead 
 of being bedded flat. 
 
 224 
 
 Herse, a portcullis ; a frame whereon 
 lighted candles were placed at the 
 obsequies of distinguished persons. 
 
 Heterogeneous, opposite or dissimilar 
 in nature, as opposed to homo- 
 geneous. 
 
 Heums, in Cornwall, the sides of a 
 calciner or burning-house furnace ; 
 so called from their being formerly 
 built with hewn moor-stone. 
 
 Hexagon, in geometry, a figure of six 
 sides or angles. 
 
 Hexahedron, in geometry, one of the 
 five regular solids, being the same 
 with a cube. 
 
 Heocastyle, a portico of six columns in 
 front. 
 
 Hcjcastylos, a frontage of six columns. 
 
 Hexeres, a vessel with six banks of 
 oars on each side. 
 
 Hiatus, an aperture, a breach or de- 
 fect. 
 
 Hick's mandril, an arbor for turning 
 rings : at the centre of the arbor 
 there is a cone, round which, at 
 equal distances, wedges are fitted 
 into dove-tailed grooves, and are 
 expanded to the bore of the ring 
 by a nut acting on a screw at the 
 end of the cone. 
 
 Hickory or white walnut, a native of 
 America. The wood of the young 
 trees is exceedingly tough and flex- 
 ible, and makes excellent hand- 
 spikes, etc. 
 
 Hieroglyphic, an emblem, a figure by 
 which a word is implied ; the 
 Egyptian art of writing in picture. 
 
 High-pressure engine, a non-conden- 
 sing steam-engine, worked by the 
 excess of the pressure of the steam 
 upon the piston above the pressure 
 of the atmosphere : in this engine, 
 after the steam has acted upon the 
 piston, it passes through the educ- 
 tion-pipe into the air. 
 
 Hiling, the covering or roof of a 
 building. 
 
 Hinges, the joints on which doors, 
 gates, etc., turn. 
 
 Hinges. The diversity of forms into 
 which door furniture has been re- 
 solved is almost endless. Many of 
 the ancient hinges were not only 
 
HIP 
 
 HOGARTH. 
 
 HOL 
 
 wrought into scrolls and other flo- 
 rid devices, but occasionally further 
 enriched with inscriptions. 
 
 Hip, the external angle formed by the 
 meeting of the sloping sides of roofs 
 which have their wall-plates run- 
 ning in different directions. 
 
 Hip-knob, a pinnacle, finial, or other 
 similar ornament, placed on the 
 top of the hips of a roof or the 
 point of a gable. 
 
 Hippodrome, a large plot of ground 
 laid out for the exercise of horses ; 
 among the Greeks, a race-course. 
 
 Hogarth (William) was born in Lon- 
 don in 1697. During his struggles 
 to quit silver plate engraving and 
 to fit himself for an artist, Ho- 
 garth writes : " I had learned by 
 practice to copy with tolerable cor- 
 rectness in the ordinary way, but 
 it occurred to me that there were 
 many disadvantages attending this 
 method of study, as having faulty 
 originals, and even when the pic- 
 tures or prints to be imitated were 
 by the best masters, it was little 
 more than pouring water out of one 
 vessel into another;" again, " Many 
 reasons led me to wish that I could 
 find the shorter path, fix forms and 
 characters in my mind, and instead 
 of copying the lines, try to read the 
 language, and, if possible, find the 
 grammar of the art, by bringing 
 into one focus the various observa- 
 tions I had made, and then trying 
 by my power on the canvas how 
 far my plan enabled me to combine 
 and apply them to practice. For 
 this purpose I considered what va- 
 rious ways, and to what different 
 purposes, the memory might be 
 applied ; and fell upon one most 
 suitable to my situation and idle 
 disposition ; laying it down as an 
 axiom, that he who could by any 
 means acquire and retain in his 
 memory perfect ideas of the sub- 
 jects he meant to draw, would have 
 as clear a knowledge of the figure 
 as a man who can write freely hath 
 of the twenty-five letters of the al- 
 phabet, arid their infinite combina- 
 
 225 L 
 
 tions." Hogarth supported him- 
 self by the sale of his prints the 
 prices of his paintings kept pace 
 neither with his fame nor with his 
 expectations. In January, 1745, 
 he offered for sale the six paint- 
 ings of the Harlot's Progress, the 
 eight paintings of the Rake's Pro- 
 gress, the Four Times a Day, and 
 the Strolling Actresses, and received 
 only 427. 7s. for his nineteen pic- 
 tures. In June, 1750, the six pic- 
 tures of Marriage-a-la-Mode were 
 sold by public auction for 110; 
 in 1797 they were sold to Anger- 
 stein for 1381. The four Elec- 
 tion Pictures, begun in 1755 and 
 finished in 1758, were sold for 
 200, and subsequently were sold 
 to Sir John Soane for 1732. 
 
 Hoggan, in Cornish, a hawthorn- 
 berry, the tinner's pasty. 
 
 Hogging, in ship-building, the convex 
 appearance resembling the back of 
 a hog, given to a ship after being 
 first launched, by the dropping of 
 the two extremities. 
 
 Hogshead, a measure of 63 gallons. 
 
 Hoist, an apparatus for raising bodies 
 from the ground-floor of a building 
 to a floor above. 
 
 Holte (Henry), of York, designed in 
 1612 several buildings. It is con- 
 jectured that he designed and com- 
 pleted the garden quadrangle build- 
 ing at Merton in 1610, and the 
 whole of Wadhain College cost 
 11,360. 
 
 Hollow newel, an opening in the mid- 
 dle of a staircase, the steps only 
 being supported at one end by the 
 surrounding wall, the ends next the 
 hollow unsupported; also a hollow 
 groin, pier, of brick or stone, made 
 behind the lock-gates of canals. 
 
 Holly is a very clean, fine-grained 
 wood, the whitest and most costly 
 of those used by the Tunbridge- 
 ware manufacturers : it is used for 
 painted screens and a great variety 
 of fancy and tasteful purposes. 
 
 Holy Trinity (The), in the Table of 
 Symbols of the early ages, by the 
 three-coloured rainbow, encircling 
 
HOL 
 
 HOPS. 
 
 HOP 
 
 our Saviour, the visible form of the 
 Deity, who is sometimes seated on 
 it, Ezek. i. 28, Rev. iv. 3 ; by the 
 beams of light from the hand of 
 Christ ; by the extension of the 
 thumb, fore and middle fingers of 
 the Saviour's hand as held in giving 
 the benediction. 
 
 Holy-water vessel, the vessel which 
 contains the consecrated or holy 
 water carried in religions proces- 
 sions ; also the receptacle for holy 
 water placed at the entrances of 
 Roman Catholic churches. 
 
 Holy-water stone, the stoup on which 
 the holy-water vessel is placed. 
 
 Holy - work folk, people who hold 
 lands for repairing or defending a 
 church or tombs, on which account 
 they were freed from feudal and 
 military service. 
 
 Homestall, or Homestead, a mansion, 
 house, or seat in the country; a 
 farm, with the land adjoining. 
 
 Homogeneous, a term applied to va- 
 rious substances, to denote that 
 they consist of similar parts, or 
 parts of the same nature and 
 kind. 
 
 Hooding s- ends, the ends of planks 
 which fit into the rabbets of the 
 stem and stern-post of a ship. 
 
 Hood-mould, a band or string over 
 the head of a door, window, or 
 other opening, in an ancient build- 
 ing ; so called from its enclosing, as 
 within a hood, the inferior mould- 
 ings and the opening itself. 
 
 Hood-moulding, a name given to the 
 label-moulding. 
 
 Hook-pins, taper iron pins, only with 
 a hook head, to pin the frame of a 
 roof or floor together. 
 
 Hops, Hop-drying. The art of drying 
 hops has been much improved 
 of late years ; emulation amongst 
 landlords and tenant-farmers, in 
 regard to the construction of their 
 oasts, has led to this. Hop-drying 
 is a process of desiccation, of which 
 the object is to drive off the su- 
 perfluous moisture from the hops. 
 Hot wind generally dries more 
 quickly than a cold one; that which 
 
 226 
 
 has the highest temperature will 
 absorb moisture from any sub- 
 stance over which it passes more 
 rapidly than the cooler current 
 will. It is not, however, so gene- 
 rally apprehended that the converse 
 of the above proposition is also 
 true, and that, with equal tempera- 
 tures, that substance over which 
 most air passes in a given time will 
 part with a larger portion of its 
 moisture. The application of the 
 latter principle has been illustrated 
 in low-temperature drying, which 
 has been managed by introducing 
 a considerable quantity of external 
 air into the space beneath the hair, 
 by knocking holes in the external 
 walls. Experiments of this sort 
 have been held to be conclusive as 
 to the superiority of low-tempera- 
 ture drying. This, however, is not 
 exactly the case, because as much 
 heat would pass through the hops 
 as before, as long as the fires were 
 kept up as usual ; and the true ex- 
 planation of the circumstance is 
 that the improved drying is due to 
 the larger quantity of air passed 
 through the hops, rather than to 
 the temperature being reduced. If 
 the fires had been lessened, the 
 temperature might have been low- 
 ered as much as was done by the 
 admission of cold air ; but in that 
 case the hops, instead of drying 
 better, would have been found not 
 to dry so well as at the higher 
 temperature. The questions which 
 are for consideration are, the quan- 
 tity of air necessary to be admit- 
 ted ; the mode of its admission ; 
 the method of heating the air ; the 
 proportion and construction of the 
 kiln necessary to give full effect to 
 the above arrangements. The quan- 
 tity of air to be admitted is depen- 
 dent upon the temperature at which 
 the drying is to be conducted, and 
 upon the weight of moisture to be 
 evaporated. Air at various tem- 
 peratures has an ascertained capa- 
 city for moisture. When fully sa- 
 turated, 
 
HOP 
 
 HOPS. 
 
 HOP 
 
 Airat32deg. contains l-160th") 
 59 l-80th | 
 
 86 l-40th g 
 
 113 l-20th I 
 
 140 l-10th f Jf 
 
 167 l-5th g 
 
 194 2-5th I 
 
 221 4-5thJ 
 
 The capacity of air for moisture 
 being doubled by each accession of 
 27 degrees of Fahrenheit. If, then, 
 we desire to know what quantity 
 of air should be admitted to carry 
 off a given weight of moisture at 
 any of the above-named tempera- 
 tures, we have only to multiply the 
 weight of moisture by the increased 
 capacity for moisture due to air raised 
 from the temperature of the exter- 
 nal atmosphere to that of the kiln. 
 Supposing the weight of water to 
 be evaporated to be 7 cwt., the 
 temperature of the external air 59 
 degrees, and that of the kiln 113 
 degrees, 186 cwt. of air would be 
 required to carry off this quantity 
 of moisture. About 13 cubic feet 
 of air weigh a pound, and rather 
 more than 270,000 cubic feet of air 
 must therefore be passed through 
 the kiln during the time of drying. 
 If we suppose this operation to be 
 continued for ten hours, this will 
 give 27,000 feet per hour, or about 
 eight feet per second. To allow 
 of the passage of so large a quan- 
 tity of air, the openings for its ad- 
 mission must be of a correspond- 
 ing area ; and as it is better to ad- 
 mit too much air than too little, it 
 would be well to adopt something 
 like the_ following proportions of 
 openings : 
 
 6 ft. superficial for a 1 6 ft. kiln. 
 8 18 
 
 10 20 
 
 12 22 
 
 The method of heating the kiln 
 has been generally regarded as the 
 most important point connected 
 with hop-drying. The requisite 
 conditions are, that the heating 
 surfaces should be largely extended, 
 and that the contact of the air- 
 
 227 
 
 currents with the heated material 
 should be perfect over the whole 
 surface. Where the former of 
 these conditions does not obtain, a 
 larger quantity of air cannot be 
 heated. In an open fire, the heat- 
 ing surfaces are nearly as the area 
 of the fire-bars ; in a common 
 cockle they may be estimated as 
 about 2-2 to 1 ; and in the im- 
 proved stove, or evaporator, they 
 are as about 30 to 1. The pecu- 
 liarities in the construction of the 
 improved stove are: The situation 
 of the fire in the centre or heart of 
 the stove at a distance from the 
 outer surfaces, which cannot there- 
 fore become overheated to the ex- 
 tent that takes place where the 
 fuel is in direct contact with the 
 sides. The exceedingly small size 
 of the fire-grate as compared with 
 the area of the fire bars, either of 
 open fires or of ordinary cockles, 
 and the consequent diminution in 
 the consumption of fuel. It has 
 been stated upon competent autho- 
 rity that the cost of drying hops 
 by ordinary cockles was about Wd. 
 per cwt., as compared with 3*. 
 where open fires and charcoal were 
 used. By the improved stove, the 
 loading of a sixteen-feet kiln might 
 certainly be dried with one cwt. of 
 coals. The more perfect combus- 
 tion of the fuel effected by lining 
 the furnace with fire-brick and the 
 higher temperature thereby in- 
 duced have much to do with the 
 efficiency of the stove. The com- 
 mon cockle being heated entirely 
 by radiated heat, absorbs none of 
 the heat from the smoke, which 
 would escape at a very high tem- 
 perature if a further portion of ca- 
 loric were not abstracted from it 
 in its circuit of the horizontal flues. 
 The principle of bringing the air 
 as it becomes warmed, in succes- 
 sive contact with still more highly- 
 heated portions of the stove, is pur- 
 sued throughout. The sides of the 
 stove are surrounded by a brick 
 wall, at a distance of about six 
 
HOR 
 
 HORSE-POWER. 
 
 HOS 
 
 inches from the stove at the nar- 
 rowest part. This wall confines 
 the air in its ascent, pressing it as 
 it were against the sides, which are 
 made to overhang, in order to give 
 more perfect contact. On reaching 
 the upper part of the side channels 
 the current of warmed air is de- 
 flected by inclined cast-iron plates, 
 and made to traverse the pyramidal 
 top of the stove, where it receives 
 its last portion of heat, and then 
 escapes upwards through the tubes 
 with which the deflecting plates 
 are perforated. It is desirable in 
 building kilns to use every precau- 
 tion to prevent the loss of heat by 
 radiation to the surrounding atmo- 
 sphere. This may be effected by 
 building the external walls hollow, 
 or with hollow bricks. An inner 
 circle answers nearly the same pur- 
 pose if there is a door to shut off 
 the communication with the shed, 
 and no openings through the ex- 
 ternal walls. The roofs should 
 also be plastered with lime and 
 hair under the tiles before the in- 
 ner plastering is done. Attention 
 to this point and to carefully stop- 
 ping all air-passages at the foot of 
 the rafters, will prevent the con- 
 densation of the reek upon the in- 
 terior of the kiln. 
 
 Hornbeam, a very tough and stringy 
 European wood, used by millwrights 
 for the cogs of wheels ; also for 
 plumbers' dressers, or mallets, etc. 
 
 Hornblende, a conspicuous ingredient 
 in the composition of rocks, divided 
 into common hornblende, horn- 
 blende-schist, and basaltic horn- 
 blende. 
 
 Horn-stone, a. conchoidal and siliceous 
 mineral substance, allied in compo- 
 sition to flint, but of a more earthy 
 texture. 
 
 Horography, the art of constructing 
 dials. 
 
 Horologium, a name anciently given to 
 any instrument for measuring time. 
 
 Horse, a large round bar of iron fixed 
 in the head of a ship. 
 
 Horse, in navigation, the name of a 
 
 rope reaching from the middle of a 
 yard to its extremity, on which the 
 sailors stand when they are loosing 
 or reefing the sails. 
 
 Horse-chestnut wood is one of the 
 white woods used by the Tunbridge 
 turners ; it is close and soft, even 
 in the grain, and is much used for 
 brush-backs, etc. 
 
 Horse-power. Although horses are 
 not all of one strength, yet there is 
 a certain force now generally agreed 
 upon among those who construct 
 steam-engines, which force is de- 
 nominated a horse's power, and 
 hence steam-engines are distin- 
 guished in size by the number of 
 horses' power to which they are 
 said to be equal. 
 
 The measure of a mechanical 
 effect equal to a horse's power has 
 been much disputed: this, however, 
 can be but a matter of little conse- 
 quence, if the measure be generally 
 understood, since there is no such 
 thing as bringing it into any real 
 measure. Some horses will perform 
 double the work of others, and 
 those of one country will work more 
 than those of another. Desaguliers' 
 measure is, that a horse will walk 
 at the rate of 2| miles per hour, 
 against a resistance of 2001bs.,and 
 this gives, as a number for compa- 
 rison, 44,000 ; that is, the raising 
 of 1 Ib. 44,000 feet in a minute, or, 
 what amounts to the same, the 
 raising of 44,000 Ibs. 1 foot in a 
 a minute. 
 
 Emerson's measure is the same 
 as Desaguliers', and Smeaton's re- 
 sult is 22,9 16 Ibs. under the same 
 circumstances. 
 
 James Watt found, from repeated 
 experiments, that 33,000 Ibs. 1 foot 
 per minute was the average value 
 of a horse's power : but his engines 
 were calculated to work equal to 
 44,000 Ibs. 1 foot per minute. 
 
 -fir.P.,theabbreviationforhorse-power. 
 
 Hortus, a garden or pleasure-ground. 
 
 Hose-pipes, in locomotive engines, 
 elastic pipes made of canvas, sa- 
 turated with a solution of India- 
 
HOS 
 
 HOT-AIR BLAST. 
 
 HOT 
 
 rubber, sometimes galvanized, and 
 forming a good elastic connection 
 between the engine and tender 
 feed-pipes. They are now generally 
 used in preference to ball-and- 
 socket connections for conveying 
 the steam to the tender. 
 
 Hospitatia, anciently the doorways in 
 the scene of a theatre on the right 
 and left of the valvae regia3 or prin- 
 cipal doorway ; so called because 
 the movable scenes, representing 
 inns or places appropriated for the 
 reception of strangers, were placed 
 near them. 
 
 Hospitals were originally designed for 
 the relief of poor and impotent per- 
 sons, and the entertainment of tra- 
 vellers upon the road, particularly 
 of pilgrims, and therefore they 
 were generally built upon the road- 
 side ; in later time they have always 
 been founded for fixed inhabitants ; 
 before the spoliation, there existed 
 in England above 358 of these 
 houses of relief. 
 
 Hostelry, or Hostry, anciently an inn. 
 
 Hot-air blast. It was conceived that 
 the presence of sulphur in the air 
 was the cause of blast furnaces 
 working irregularly and making 
 bad iron in the summer months. 
 Subsequently it was stated that one 
 of the Muirkirk iron furnaces, in 
 Scotland, situated at a considerable 
 distance from the engine, did not 
 work so well as the others, which 
 led to the conjecture that the fric- 
 tion of the air, in passing along the 
 pipe, prevented an equal volume 
 of the air getting to the distant 
 furnace as to the one which was 
 situated close by the engine : it was 
 considered also, that by heating the 
 air at the distant furnace, its volume 
 would increase in the ratio of the 
 known law, that air and gases ex- 
 pand to double their bulk at 448 
 temperature. 
 
 Example : If 1000 cubic feet, 
 say at 50 of Fahrenheit, were 
 pressed by the engine in a given 
 time, and heated to 600 of Fah- 
 renheit, it would then be increased 
 
 in volume to 2104-4, and so on for 
 every thousand feet that would be 
 blown into the furnace. In prose- 
 cuting the experiments which this 
 idea suggested, circumstances, how- 
 ever, became apparent which in- 
 duced a belief, that heating the air 
 introduced for supporting combus- 
 tion into air-furnaces materially in- 
 creased its efficiency in this re- 
 spect ; and with the view of putting 
 these suspicions to the test, the 
 following experiments were made. 
 
 To the nozzle of a pair of common 
 smith's bellows, a cast-iron vessel 
 heated is attached from beneath, in 
 the manner of a retort for gene- 
 rating gas, and to this vessel the 
 blow-pipe, by which the forge or 
 furnace was blown, was also at- 
 tached. The air from the bellows 
 having thus to pass through the 
 heated vessel above mentioned, was 
 consequently heated to a high tem- 
 perature before it entered the forge 
 fire, and the result produced, in 
 increasing the intensity of the heat 
 in the furnace, was far beyond ex- 
 pectation, and so evident as to make 
 apparent the fallacy of the generally 
 received opinion, that the coldness 
 of the air of the atmosphere in the 
 winter months was the cause of the 
 best iron being then produced. 
 
 In overthrowing the old theory, 
 new principles in the process of 
 iron-making were established. 
 
 Experiments on the large scale, 
 to reduce iron ore in a founder's 
 cupola, were commenced at the 
 Clyde Iron-works. These experi- 
 ments were completely successful, 
 and in consequence the invention 
 was immediately adopted at the 
 Calder Iron-works, where the blast, 
 being made to pass through two 
 retorts placed on each side of one 
 of the large furnaces before entering 
 the furnace, effected an instanta- 
 neous change, both in the quantity 
 and quality of iron produced, and 
 a considerable saving of fuel. 
 
 The whole of the furnaces at the 
 Calder and Clyde Iron-works were 
 
 229 
 
HOT 
 
 HOUSE. 
 
 HOU 
 
 fitted up]on the principle of the hqt 
 blast, and its use at these works 
 continues to be attended with the 
 utmost success; it has also been 
 adopted at Wilsontown and Gart- 
 shirrie Iron-works in Scotland, 
 and at several works in England 
 and France. 
 
 The air as at first raised to 250 
 of Fahrenheit, produced a saving of 
 three-sevenths in every ton of pig- 
 iron made, and the heating appa- 
 ratus having since been enlarged, 
 so as to increase the temperature of 
 the blast to 600 Fahrenheit and 
 upwards, a proportional saving of 
 fuel is effected ; and an immense 
 additional saving is also acquired 
 by the use of raw coal instead of 
 coke, which may now be adopted. 
 By thus increasing the heat of the 
 blast, the whole waste incurred in 
 burning the coal into coke is avoided 
 in the process of making iron. 
 
 By the use of this invention, 
 with three-sevenths of the fuel 
 formerly employed in the cold-air 
 process, the iron-maker is now 
 enabled to make one-third more 
 iron of a superior quality. 
 
 Were the hot blast generally 
 adopted, the saving to the country 
 in the article of coal would be 
 immense. In Britain, about 700,000 
 tons of iron are made annually, of 
 which 50,000 tons only are pro- 
 duced in Scotland : on these 50,000 
 tons would be saved, in the pro- 
 cess of manufacture, 200,000 tons 
 of coal annually. In England the 
 saving would be in proportion to 
 the strength and quality of the 
 coal, and cannot be computed at 
 less than 1,520,000 tons annually; 
 and taking the price of coals at the 
 low rate of four shillings per ton, 
 a yearly saving of 296,000 ster- 
 ling would be effected. 
 
 Nor are the advantages of this 
 invention solely confined to iron- 
 making : by its use the founder can 
 cast into roods an equal quantity 
 of iron in much less time, and with 
 a saving of nearly half the fuel 
 
 230 
 
 employed in the cold-air process ; 
 and the blacksmith can produce in 
 the same time one-third more work, 
 with much less fuel than he for- 
 merly required. 
 
 In all the processes of metallur- 
 gical science it will be found of the 
 utmost importance in reducing the 
 ores to a metallic state. 
 
 Hospitium, in old writers, an inn or a 
 monastery, built for the reception 
 of strangers and travellers. 
 
 Hot-house, a glass building used in 
 gardening, and including stoves, 
 conservatories, etc. 
 
 Hot-water pump, the feed-pump of a 
 condensing engine, for supplying 
 the boiler from the hot well. 
 
 Hot well, the vessel which receives 
 the water from the air-pump. 
 
 Hour-glass stand, a bracket or frame 
 of iron for receiving the hour-glass. 
 See ' Papers on Architecture,' vol. 
 iii., which contains a good example. 
 " By the side of the pulpit still 
 remains the ancient hour-glass and 
 frame." 
 
 House, a place of residence. The pur- 
 pose of a house being for dwelling, 
 and that of tents being the same, 
 they are called by one name in the 
 Hebrew ; on the same principle, the 
 Tabernacle of God, though only a 
 tent, is sometimes called the Tem- 
 ple, that is, the residence of God. 
 The ordinary buildings or houses 
 in the East have continued the same 
 from the earliest ages, without the 
 least alteration or improvement ; 
 large doors, spacious chambers, 
 marble pavements, cloistered courts, 
 with fountains, etc., conveniences 
 well adapted to the circumstances 
 of these climates, where the sum- 
 mer heats are generally intense. The 
 streets of these cities, the better to 
 shade them from tb.e sun, are usu- 
 ally narrow, with sometimes a range 
 of shops on each side. On enter- 
 ing one of the principal houses, a 
 porch or gateway will first be seen, 
 with benches on each side, where 
 the master of the family receives 
 visits and despatches business. In 
 
HOU 
 
 HOUSE. 
 
 HOU 
 
 houses of better fashion, the cham- 
 bers are hung with velvet or 
 damask from the middle of the 
 wall downwards, and covered and 
 adorned with velvet or damask 
 hangings of white, blue, red, green, 
 or other colours. The ceiling is 
 generally of wainscot, either very 
 artistically painted, or else thrown 
 into a variety of panels with gilded 
 mouldings, and with scrolls of the 
 Koran, etc. The stairs are some- 
 times placed in the porch, some- 
 times at the entrance into the court. 
 When there is one or more stories, 
 they are afterwards continued, 
 through one corner or other of the 
 gallery, to the top of the house, 
 whither they conduct through a 
 door that is generally kept shut, 
 to prevent their domestic animals 
 from daubing the terrace, and 
 thereby spoiling the water which 
 falls from thence into the cisterns 
 below the court, etc. Such in 
 general are the manner and contri- 
 vances of the Eastern houses ; and 
 if it may be presumed that our 
 Saviour, at the healing of the para- 
 lytic, was preaching in a house of 
 this fashion, it may, by attending 
 only to the structure of it, throw 
 some light on one circumstance of 
 that history, which has given great 
 offence to some unbelievers. The 
 houses of the poorer class of people 
 in the East are of very bad con- 
 struction, consisting of mud walls, 
 reeds, and rashes. In Constanti- 
 nople everything is sacrificed to 
 outside decorative show: built prin- 
 cipally of wood, conflagrations are 
 frequent and extensive. In earlier 
 history, magnificence and refined 
 luxury were combined with the 
 highest and most noble examples of 
 decorative art. The interior of the 
 domestic residences and public edi- 
 fices of Herculaneum and Pompeii 
 surpassed every existing example. 
 The houses of the Roman citizens 
 partook also of the refinement of 
 an age of art ; and modern Europe 
 has noble examples of domestic 
 
 231 
 
 dwellings, coeval with the wealth 
 of the country in which they are 
 still to be found. In England, the 
 domestic residence of the noble- 
 man, the merchant, and the trader 
 are, besides the elegances of their 
 arrangements, models of comfort 
 and health. 
 
 Before a house is planned, the 
 proprietor should describe the 
 kind of house he wishes to be built. 
 The architect is to consider what 
 must be had, and what may be dis- 
 pensed with. He ought to keep 
 his plan as scrupulously within the 
 expense proposed, as within the 
 limits of the ground he is to build 
 upon ; he is, in short, to enter into 
 the views, the wishes, and the ideas 
 of the gentleman who will inhabit 
 the house proposed to be erected. 
 
 Houses suitable to the different 
 ranks of the community. Vitru- 
 vius instructs us of those parts of 
 private houses which are exclu- 
 sively appropriated to individuals 
 of the family, and in what manner 
 these ought to be connected with 
 the apartments into which strangers 
 are admitted ; for there are several 
 parts of a house which may not be 
 approached by those who are riot 
 of the household, unless expressly 
 invited ; such as the sleeping-rooms, 
 triclinia, baths, and those apart- 
 ments which are in general use. 
 The parts which are accessible to 
 all, and into which any person may 
 enter uninvited, are the vestibule, 
 cavsedium, peristyle, and whatever 
 others are built for similar pur- 
 poses. 
 
 Of the proportions of private 
 houses, Vitruvius says : " Nothing 
 ought to engage the attention of 
 an architect more than the pro- 
 portions of all the parts in the 
 houses he constructs : after having 
 determined upon such proportions 
 as the necessity for the commen- 
 suration of the parts with the entire 
 building seems to require, the great- 
 est judgment must be exercised in 
 adapting them to the nature of the 
 
HOU 
 
 HYDRAULICS. 
 
 HYD 
 
 spot, the use to which the edifice 
 are designed, and the appearance 
 they ought to assume ; and this 
 must be done by making such addi- 
 tions or deductions, that, although 
 the proportions are not strictly what 
 they ought to be, the eye may not 
 be conscious wherein they fail. The 
 same objects appear differently 
 under dissimilar circumstances ; if 
 near the ground or at a considerable 
 elevation ; if in a confined space or 
 an exposed situation. Under every 
 peculiar circumstance, great judg- 
 ment is necessary in calculating the 
 effect which will be ultimately pro- 
 duced. The impression made upon 
 the sense of seeing is not always 
 a correct image of the object ; for, 
 in painting, columns, mutules, and 
 statues are made to appear pro- 
 jecting and detached, when, in fact, 
 every object represented is in one 
 and "the same plane. It becomes 
 necessary, in the first place, to in- 
 stitute laws of proportion, upon 
 which all our calculations must be 
 founded. According to these, the 
 ground-plan, exhibiting the length 
 and breadth of the whole work 
 and the several parts of it, must be 
 formed. When the magnitude of 
 these is once determined, the parts 
 must be arranged so as to produce 
 that external beauty which suffers 
 no doubt to arise in the minds of 
 those who examine it as to the 
 want of proportion in any part." 
 
 The Greeks had a different way 
 of building from the Romans ; for, 
 as Vitruvius says, " instead of mak- 
 ing porticoes or galleries and halls, 
 they made the entry to their 
 houses very narrow, placing on 
 one side the stables, and the por- 
 ter's lodge on the other. From 
 this first entry one passed into a 
 court, which had piazzas on three 
 sides, and towards that of the 
 south they made anti, or abut- 
 ments of pilasters, which supported 
 the joists of the ceiling more in- 
 wards ; because that leaving some 
 space between the one and the 
 
 other, they had very large places, 
 which they appointed for lodging 
 to the mistress of the house, and 
 to the men and women servants. 
 On the same floor with these abut- 
 ments there were some rooms which 
 may be called antechambers, cham- 
 bers and drawing-rooms, being 
 every one just behind the other." 
 
 House-bote, an allowance of timber 
 out of the lord's wood, to support or 
 repair a tenant's house. 
 
 Housing, a tabernacle, or niche for a 
 statue, was formerly so called. 
 
 Hovel. The canopies over the heads 
 of the statues of Richard II. and 
 Queen Anne are called hovels or 
 tabernacles. 
 
 Howl, or To Howie, when the foot- 
 hooks of a ship are scarfed into the 
 ground-timbers, etc. 
 
 Huel, a work, a mine, as huel stones, 
 a tin mine. 
 
 Hulk, in Cornwall, an old excavated 
 working ; l to hulk the lode.' 
 
 Hulk, or hull, the body of a ship. 
 
 Hummums (Turkish), a sweating 
 house. 
 
 Hungarian machine, an hydraulic en- 
 gine, a very ingenious application 
 of the Hero jet-d'eau principle. 
 
 Hydraletes, according to Strabo, a 
 mill for grinding corn by water- 
 power. 
 
 Hydraulic belt, an endless double 
 band of woollen cloth, passing over 
 two rollers, the lower part of the 
 belt being immersed in water : it is ; 
 driven with a velocity of not less j 
 than a thousand feet per minute, ' 
 and the water contained between i 
 the two surfaces is carried up and ! 
 discharged, as it passes over the 
 upper roller, by the pressure of the 
 band. 
 
 Hydraulic ram, a machine contrived 
 to raise water by means of its own 
 momentum. 
 
 Hydraulics. The science of hydraulics 
 teaches the method of estimating 
 the swiftness and force of fluids in 
 motion. The science is dignified 
 by the name of hydrodynamics, or 
 the application of dynamics to the 
 
HYD 
 
 HYDRAULIC PRESS. 
 
 HYD 
 
 impulsion and flow of water and 
 other liquids, as well as the forces 
 with which they act upon bodies 
 against which they strike, or which 
 move in them. 
 
 Hydrodynamics, the science of the 
 laws of the motion of fluids, con- 
 sisting of two branches. The 
 science of hydraulics refers princi- 
 pally to the machinery for conduct- 
 ing fluids ; that of hydrostatics, 
 to the pressure, equilibrium, and 
 cohesion of fluids. 
 
 Hydrogen. Hydrogen gas is com- 
 monly obtained for experimental 
 purposes by the decomposition of 
 water: its name is derived from 
 the Greek words meaning water 
 and to generate. 
 
 Hydrometer, an instrument for mea- 
 suring the specific gravity of va- 
 rious spirits and other liquids, by 
 floating in them. 
 
 Hydroscope, an instrument intended 
 to mark the presence of water in 
 air. 
 
 Hydrostatic or Hydraulic Press, a 
 machine adapted for giving great 
 pressure in cases where little mo- 
 tion is required. The contrivance 
 of this apparatus is due to the ce- 
 lebrated mechanician, Joseph Bra- 
 mah, who obtained a patent for it 
 on the 31st of March, 1796, under 
 the title of ' certain new methods 
 of producing and applying a more 
 considerable degree of power to all 
 kinds of mechanical apparatus and 
 other machinery requiring motion 
 and force, than by any means at 
 present practised for that purpose.' 
 The action of this press is founded 
 upon the fundamental principle in 
 hydrostatics, that " when a liquid 
 mass is in equilibrium, under the 
 action of forces of any kind, every 
 molecule or part of the mass sus- 
 tains an equal pressure in all direc- 
 tions." From this it follows, that 
 a pressure exerted on any portion 
 of the surface of a confined mass of 
 fluid is propagated throughout the 
 mass, and transferred undiminished 
 to the entire surface in contact 
 
 with the water. The first sugges- 
 tion of the hydraulic press is con- 
 sidered to have been made by Pas- 
 cal in the middle of the 17th cen- 
 tury ; but Bramah was the first to 
 carry this suggestion into practice, 
 by devising and applying apparatus 
 in various forms for the purpose of 
 producing pressure. 
 
 Since the data of its invention, 
 the hydraulic press has been ex- 
 tensively used in pressing goods of 
 various kinds. Another of its most 
 useful applications is to the testing 
 Fig. i. 
 
 of girders and beams of cast-iron. 
 (See article BramaWs Hydrostatic 
 Press.) Its latest and perhaps most 
 remarkable duty is that of lifting 
 the iron-work of tubular bridges en 
 masse from the water-level to their 
 final altitude. 
 
 Hydrostatic presses consist es- 
 
 233 
 
HYD 
 
 HYDRAULIC PRESS. 
 
 HYD 
 
 sentially of two distinct parts, viz. 
 the press, or machine in which the 
 force acquired is applied, and the 
 pumping apparatus, by which the 
 water is forced into the press ; these 
 two parts of the entire machine 
 being connected only by the pipe 
 
 Fig. 2. 
 
 through which the water passes 
 from one to the other. Of the ac- 
 companying figures, Nos. 1 and 2 
 show the main parts of the press, 
 viz. the cylinder, into which the 
 water is admitted ; the ram, or solid 
 plunger or piston ; and the cross- 
 head by which the pressure at the 
 end of the ram is distributed over 
 a lengthened surface for use. The 
 figures show the cylinder as sup- 
 
 2 34 
 
 ported in a frame upon girders, in 
 a manner similar to that adopted 
 in raising the tubes of the railway 
 bridge erected at Conway. 
 
 Fig. 3 shows the section of a 
 portable forcing-pump as commonly 
 used for proving castings with the 
 hydraulic press, for which purpose 
 the press is applied horizontally, 
 and mounted on an iron carriage 
 for portability. But, however va- 
 ried in arrangement for particular 
 purposes, the pump and the press 
 consist of the same essential parts, 
 as follows : the pump comprises a 
 cistern or kind of pail for contain- 
 ing the water, and into which a 
 barrel descends nearly to the bot- 
 tom. The barrel is fitted with a 
 plunger, by working which, the 
 water is driven through a small 
 tube or pipe into the press. The 
 pump is furnished with a safety- 
 valve, and also with a screw for 
 letting off the water as required. 
 The press consists of a strong hol- 
 low cylinder of cast-iron, close at 
 one end, and of a solid ram work- 
 ing through the other end, the 
 water-pipe being inserted through 
 the metal of the cylinder in a water- 
 tight screwed aperture. Fig. 1 is 
 an elevation of the press ; fig. 2, a 
 vertical section of the press, taken 
 at right angles to the elevation ; 
 and fig. 3, a vertical section of a 
 pump : a is the cast-iron cylinder ; 
 b, the ram ; c, the casing or frame 
 of the cylinder ; d d are two cast- 
 iron girders supporting the casing; 
 e is the cast-iron cross-head ; //, 
 two guide-rods ; g, the water-pipe 
 from the pump, with a lever-valve 
 at h, by closing which the pressure 
 will be retained, should the pipe 
 burst. On fig. 3,^' shows the other 
 end of the water-pipe, which is at i 
 screwed into a stuffing-box on the 
 pump ; k is the lever of the safety- 
 valve, a, which is cylindrical, and 
 finished with a conical end, which 
 fits a seating of similar form ; / is 
 a standard bolted at m to the cover 
 of the cistern, and having an eye- 
 
HYD 
 
 HYDRAULIC PRESS. 
 
 HYD 
 
 boss at n, for guiding the plunger ; 
 o p is a link pinned to the plunger ; 
 q is the pail or cistern for holding 
 the water; r, the barrel passing 
 through an opening in the cover, 
 and fixed to it with bolts and nuts ; 
 *, the lower valve-seat, and conical 
 
 Fig. 3. 
 
 three-sided valve, the former being 
 screwed into the end of the barrel ; 
 t, a tube depending from the valve- 
 seat s, and screwed upon it : this 
 tube reaches nearly to 4he bottom 
 of the cistern, and is perforated at 
 the end with minute apertures, 
 through which the water is ad- 
 mitted without dirt or particles, 
 which would injure the working of 
 
 235 
 
 the pump ; u is the plunger, which 
 works through a stuffing-box on 
 the top of the barrel, and is made 
 with a slot at v, to receive the link 
 o p, which is pinned to it and also 
 to the pump-handle; w is the 
 plunger-rod, screwed into the upper 
 end of the plunger ; y, the pump- 
 handle, jointed to the standard at x. 
 During the first part of the action 
 of the pump, while no great pres- 
 sure is yet produced, the handle is 
 pinned to the outer of these holes, 
 as it makes a larger stroke with 
 the piston, and thus saves time: 
 the pin is afterwards removed to 
 the inner hole, to have all the ad- 
 vantage of the leverage, z is the 
 upper or discharge valve, with a 
 conical end : it is introduced from 
 the top, and covered with a short 
 screw, which likewise re- 
 gulates the lift of the 
 valve. This valve is form- 
 ed by being simply filed 
 flat out of the round. 
 The rule for finding the increase 
 of power commanded by the pump 
 is derived, first, from the ratio of 
 the areas of cross-section of plunger 
 of pump and ram of press; and, 
 secondly, from the ratio of the le- 
 verage of the pump-handle. Thus 
 suppose the plunger to be \ inch 
 and the ram 6 inches in diameter, 
 and the arms of the lever or handle 
 as 1 to 4, the power will be thus 
 
 found : 
 
 .52 . 6 2 
 
 multiplied by 1 : 4 
 
 25 : 144, 
 that is, 1 : 576. 
 
 And thus a power equal to 201bs., 
 applied on the end of the pump- 
 handle, will produce a pressure 
 equal to ll,5201bs. on the ram, or 
 5 tons 2 cwt. 3 qrs. 121bs. 
 
 Each of the presses applied at 
 Conway was worked by a steam- 
 engine having a horizontal cylinder 
 17 inches in diameter and 16 inches 
 stroke, with piston-rods working 
 through stuffing-boxes at both ends 
 
HYD 
 
 HYGROMETER. 
 
 IDE 
 
 of the cylinder. The piston-rods, 
 worked two forcing-pumps, with 
 plungers 1 T ^ inch diameter and 16 
 inches stroke. The rams of these 
 presses were each 5 feet 2 inches 
 long and 18f inches in diameter, 
 with a space nearly | inch wide 
 around. The cylinders were 37 
 inches diameter externally, and 20 
 inches internally, the metal being 
 8| inches in thickness: the orifice 
 of the water-tubes f inch in dia- 
 meter. 
 
 Hydrostatic paradox. This may be 
 explained upon the same principles 
 as the mechanical powers ; and an 
 explanation conducted in this man- 
 ner strips it of its paradoxical ap- 
 pearance. 
 
 Hydrostatics, the science which treats 
 of the mechanical properties of 
 fluids; strictly speaking, the weight 
 and equilibrium of fluids. The 
 weight and equilibrium of fluids at 
 rest are the objects of this science. 
 When the equilibrium is destroyed, 
 motion ensues ; and the science 
 which considers the laws of fluids 
 in motion is hydraulics. 
 
 Hygrometer : this instrument is used 
 to ascertain the quantity of mois- 
 ture held in the atmosphere. There 
 are several kinds of hygrometers 
 in use,namely, De Luc's, Saussure's, 
 Leslie's, and Professor Daniell's. 
 The latter is considered preferable. 
 
 Hypcethral, open above : in temples 
 of this description the cella was 
 in part exposed to the air: they 
 
 had a double range of columns 
 within the cella, dividing it into 
 three alae, or aisles. The alas on 
 either side were roofed, but that in 
 the middle had no covering. 
 
 Hypcethrum, a latticed window over 
 the entrance-door of a temple. 
 
 Hyperbola, a section of a cone made 
 by a plane, so that the axis of the 
 section inclines to the opposing leg 
 of the cone, which in the parabola 
 is parallel to it, and in the ellipse 
 intersects it. 
 
 Hyperthyrum, that part of the frame 
 of a doorway which is over the 
 supercilium. In Greek architec- 
 ture, a frieze and cornice supported 
 by friezes and consoles. 
 
 Ifypocastanum, or chestnut brown, is 
 a brown lake prepared from the 
 horse-chestnut : it is transparent 
 and rich in colour, warmer than 
 brown pink, and very durable both 
 in water and oil ; in the latter it 
 dries moderately well. 
 
 Hypocausis, among the Greeks, a fur- 
 nace with flues running underneath 
 the pavement of an apartment, to 
 increase the temperature. 
 
 Hypocaustum, the stove-room of a 
 bath, in which was placed the prse- 
 furnium for heating the caldaria. 
 
 Hypogaeum, in ancient architecture, a 
 name common to all the under- 
 ground parts of a building. 
 
 Hypotrachelium, that part of the ca- 
 pital of a column which occurs be- 
 tween the shaft and the annulets 
 of the echinus. 
 
 I. 
 
 ICE-HOUSE, a subterranean chamber 
 for preserving ice from the ordinary 
 changes of temperature. 
 
 Ich Dien, in heraldry, ' I serve.' 
 
 Ichnography, in drawing. The ichno- 
 graphy of a building represents the 
 plan or groundwork ; the ortho- 
 graphy, the front ; and the sceno- 
 graphy, the whole building. 
 
 Icosahedron, in geometry, a regular 
 body or solid, consisting of twenty 
 triangular pyramids. 
 
 236 
 
 Ideas. 1. Formation of ideas, intel 
 lect, mind, understanding, reason* 
 thinking principle, nous, sense, 
 common sense, consciousness, ca- 
 pacity, intelligence, intellection. 
 2. Precursory conditions and ope- 
 ration. 3. Materials for reasoning. 
 4. Reasoning processes. 5. Results 
 of reasoning. 6. Extension of 
 thought. 7. Creative thought. 
 
 Communication of Ideas. 1. 
 Nature, of ideas communicated, 
 
IMA 
 
 INDIAN ARCHITECTURE. 
 
 IND 
 
 meaning, signification, sense, modes 
 of communication, means of com- 
 municating ideas. 
 
 Individual Volition. 1. Will, 
 volition, free-will. 2. Prospective 
 volition. 3. Voluntary action. 
 4. Antagonism. 5. Results of 
 voluntary action, intersocial voli- 
 tion. 
 
 Image, a term applied to a statue. 
 
 Imbowment, an arch or vault. 
 
 Immure, a wall or inclosure. " With- 
 in whose strong immures." Shak- 
 speare. 
 
 Impages, the horizontal parts of the 
 frame-work of doors, commonly 
 termed rails. 
 
 Impetus, in mechanics, violent ten- 
 dency to any point, violent effort, 
 force, momentum, motion. 
 
 Impinge, in mechanics, to fall against, 
 to strike against, to clash with. 
 
 Impluvium, the cistern in the central 
 part of the court or atrium of a 
 Roman house, to receive the rain- 
 water. 
 
 Impost, the horizontal mouldings or 
 capitals on the top of a pilaster, 
 pillar, or pier, from which an arch 
 springs : in classical architecture 
 the form varies in the several orders. 
 Sometimes the entablature of the 
 order serves for the impost of an 
 arch. 
 
 Impost, archivolt, and key-stone. The 
 height of the impost should be from 
 one-ninth to one-seventh of the 
 width of the aperture, and the 
 breadth of the archivolt not more 
 than an eighth nor less than a 
 tenth of it. The breadth of the 
 under-side of the key-stone should 
 be the same as the breadth of the 
 archivolt, and its sides, of course, 
 concentric ; its length, once and a 
 half its breadth, but not more than 
 double its breadth. 
 
 Impulsive force is that which acts 
 during an extremely short time, 
 and is so called because the forces 
 that take place in any impulse, or 
 impact, are speedily exhausted. 
 
 Incise, to cut, to engrave, to carve. 
 
 Inclined plane (the), in mechanics, is 
 
 237 
 
 a plane which makes with the hori- 
 zontal plane any angle whatever, 
 forming one of the simplest me- 
 chanical powers. The inclination 
 of the plane is measured by the 
 angle formed by two lines drawn 
 from the sloping and the hori- 
 zontal plane, perpendicular to their 
 common intersection. 
 
 Increment, an increase, produce. 
 
 Incrustation. If water, impregnated 
 with calcareous matter, remains 
 long in contact with extraneous 
 substances, an earthy incrustation 
 takes place that soon encloses the 
 incrusted substance, which is then 
 said to be petrified. 
 
 Incrusted, in architecture, applied 
 to walls or columns covered with 
 precious marble or stone. 
 
 Incumba, that part of a column or 
 pillar on which the weight of a 
 whole building lies. 
 
 Indian Architecture consists of two 
 distinct styles, the Buddhist and 
 the Brahminical, the former being 
 the earliest, and consisting of topes 
 or tumuli, large domical buildings 
 of brick or stone, either quite solid 
 or containing one or more small 
 chambers, in which are deposited 
 relics, coins, and other similar ob- 
 jects, which the greater number of 
 them were erected to enshrine. 
 The principal topes are now found 
 in Ceylon and Afghanistan, but 
 they also exist in Burmah and in 
 other neighbouring countries. 
 
 The next class of Buddhist 
 buildings are the Chaitya halls, 
 similar in plan and use to the early 
 basilica : these exist principally in 
 caves in India. And lastly, viharas 
 or monasteries, in which the monks 
 attached to the Chaitya halls re- 
 sided: these also exist principally 
 as caves in India, and as structural 
 buildings in all countries where 
 Buddhism is still practised. 
 
 Brahminical or Hindoo architec- 
 ture consists mostly of temples, pro- 
 perly so called. These in almost 
 every instance are towers, square in 
 plan, or nearly so, built over the cell 
 
IND 
 
 INDICATOR. 
 
 INE 
 
 or sanctum of the temple. In the 
 south of India, the upper part forms' 
 a right-lined pyramid; in the north, 
 the outline is curvilinear, sometimes 
 tapering to a spire. 
 
 To these towers are attached 
 porches of greater or less dimen- 
 sions. In the north there are 
 generally square halls without pil- 
 lars in the south, as universally 
 pillared sometimes attached, at 
 others detached from the temple 
 itself: in the latter case, in the 
 south, some of the porches possess 
 from 500 to 1000 pillars, though 
 this is never the case in the north. 
 
 These temples are generally sur- 
 rounded by a square court : in the 
 south, three, four, and sometimes 
 even seven such enclosures sur- 
 round the principal cell, the outer 
 one being, in many instances, some 
 miles in circumference. 
 
 These Hindoo temples exist 
 sometimes, though rarely, as rock- 
 cut temples ; but generally they are 
 structural. 
 
 Between these styles comes a 
 third, the Jaina style, being a mix- 
 ture of the two, possessing some 
 of the characteristics of both, and 
 frequently displaying more ele- 
 gance than the first, and less taw- 
 driness than the other. By the 
 introduction of domes, whose use 
 was thus brought to great perfec- 
 tion, an element was added which 
 was a great improvement on the 
 other two styles, and from which 
 that of Jaina originated. 
 
 The absence of the arch in all 
 constructions of every age is gene- 
 ral throughout India, as the prin- 
 ciple was quite unknown. The 
 upper parts of the buildings were 
 supported on square piers or pil- 
 lars, and from all sides of their 
 capitals brackets projected equal 
 to their width, and leaving gene- 
 rally a space equal to three diame- 
 ters between their greatest projec- 
 tion, thus leaving only one-half of 
 the whole length of the architrave 
 unsupported ; but when a greater 
 
 238 
 
 space was required, a succession of 
 projecting brackets, placed above 
 each other, was adopted, sometimes 
 meeting in the centre, and thus 
 having the effect of the horizontal 
 arch. 
 
 Indian Ink : the pigment well known 
 under this name is principally 
 brought from China in oblong 
 cakes, of a musky scent, prepared 
 for painting in water, etc. 
 
 Indian red, a colour, is brought from 
 Bengal, and is a very rich iron ore, 
 or peroxide of iron. It is an ano- 
 malous red, of a purple-russet hue, 
 of a good body, and valued, when 
 fine, for the pureness and lakey 
 tone of its tints. 
 
 Indian yellow is a pigment long em- 
 ployed in India and subsequently 
 introduced generally into painting 
 in European countries. It is im- 
 ported in the form of balls, is of a 
 fetid odour, and is produced from 
 the urine of the camel. It has 
 also been ascribed, in like manner, 
 to the buffalo, or Indian cow, after 
 feeding on mangoes ; but the latter 
 statement is incorrect. Indian yel- 
 low resists the sun's rays with sin- 
 gular power in water-painting. 
 
 Indicator, the apparatus for showing 
 the force of the steam, and the 
 state of exhaustion in the cylinder 
 during the stroke. 
 
 Inigo (Jones), born in London, was 
 first employed at Oxford in 1635 ; 
 he built the arcades and porticoes 
 of the inner quadrangle of St. 
 John's College with a gallery over ; 
 also York-stairs, Strand; and his 
 magnificent design for a royal 
 palace at Whitehall has not yet 
 been surpassed. 
 
 Indigo, or Indian blue, is a pigment 
 manufactured in the East and West 
 Indies from several plants, but 
 principally from the anil or indi- 
 gofera. 
 
 Inertia, the passiveness of matter: 
 matter has not the power of putting 
 itself into motion, neither has it 
 the power of stopping itself when 
 put into motion by the action of 
 
INF 
 
 INTERCOLUMNIATION. 
 
 INT 
 
 an external force, as it requires as 
 much force to stop a body as it 
 requires to put it in motion. 
 
 Inflammable air, hydrogen gas. 
 
 Influx, in hydraulics, the act of flow- 
 ing into any thing, as the tide into 
 a bay or river. 
 
 Injection-cock, the stop-cock in the 
 ejection -pipe, for shutting off the 
 supply of cold water used for the 
 condensation of steam. 
 
 Injection-pipe, the pipe through which 
 the injection water passes to the 
 condenser ; in a steam-vessel the 
 injection-pipe is open to the sea, at 
 the bottom of the vessel. 
 
 Inn, or hostel, anciently a lodging- 
 house, or a house of lodging and 
 refreshment for travellers : houses 
 for lodging the collegians at Cam- 
 bridge and Oxford were so called. 
 
 Inns of court, houses in which there 
 are many lodgings for the accom- 
 modation of students and practi- 
 tioners at law. 
 
 Innate force, in physics, the vis iner- 
 tia?. 
 
 Inner-post, in ship-building, a piece 
 brought in *at the fore-side of the 
 main-post, and generally continued 
 as high as the wing-transom, to 
 seat the other transoms upon. 
 
 Insertum opus, according to Vitru- 
 vius, a mode of building walls used 
 by the Romans, in which the stones 
 were small and unhewn, similar to 
 what is now called rubble-work. 
 
 Insulated columns, in architecture, 
 are those which are unconnected 
 with any wall or building. 
 
 Intaglio, in sculpture, etc., anything 
 that has figures engraved on it, so 
 as to rise above the ground. 
 
 Intense blue, indigo refined by so- 
 lution and precipitation, in which 
 state it is equal in colour to Ant- 
 werp blue. By this process, indigo 
 also becomes durable, and much 
 more powerful, transparent, and 
 deep. It washes and works well in 
 water; and in other respects it has 
 the common properties of indigo. 
 
 Intercolumniation. The space be- 
 tween two columns is called an in- 
 
 239 
 
 tercolumniation. When columns 
 are attached to the wall, this space 
 is not under such rigorous laws as 
 when they are quite insulated ; for, 
 in the latter case, real as well as 
 apparent solidity requires them to 
 be near each other, that they may 
 better sustain the entablatures 
 which it is their office to carry. 
 
 DIFFERENT SORTS. The dif- 
 ferent intercolumniations had the 
 following names bestowed on them 
 by the Greeks, and they still retain 
 their ancient appellations : 
 Pycnostylos, when the columns are 
 once and a half of 
 their diameter dis- 
 tant from each other. 
 Systylos . . when their distance 
 from each other is 
 two diameters. 
 
 Eustylos . . when their distance 
 from each other is 
 two diameters and a 
 quarter. 
 
 Diastylos . . when their distance 
 from each other is 
 three diameters and 
 quarter. 
 
 Ara3ostylos. when their distance 
 from each other is 
 four diameters. 
 
 In the Doric, however, the in- 
 tercolumniation is regulated by the 
 disposition of the triglj phs in the 
 frieze ; for the triglyph ought al- 
 ways to be placed over the centre 
 of a column, and the metope should 
 be square. In the Tuscan inter- 
 val, the architraves being of wood, 
 the space may be considerably ex- 
 tended. 
 
 A strict adherence to the above- 
 named intervals between the co- 
 lumns produces some irregularity 
 in the arrangement of the modil- 
 lions and dentils of the Corinthian, 
 Ionic, and Composite cornices, 
 which, though not offensive, is 
 better avoided. Vignola therefore 
 has, with some propriety, made his 
 eustylos intercolumniation equal to 
 two diameters and one-third in all 
 but the Doric order. 
 
INT 
 
 IODINE SCARLET. 
 
 IOD 
 
 Intercolumniations. Columns may be 
 said to be either engaged or insu"- 
 lated : when insulated, they are 
 either placed very near the walls 
 or at some considerable distance 
 from them. 
 
 With regard to engaged columns, 
 or such as are near the walls of a 
 building, the intercolumniations are 
 not limited, but depend on the 
 width of the arches, windows, 
 niches, or other objects, and their 
 decorations, placed within them. 
 But columns that are entirely de- 
 tached, and perform alone the office 
 of supporting the entablature, as in 
 peristyles, porches, and galleries, 
 must be near each other, both for 
 the sake of real and apparent so- 
 lidity. 
 
 The ancients had several man- 
 ners of spacing their columns, 
 which are described by Vitruvius 
 in his third and fourth books. 
 Those practised in the Ionic and 
 Corinthian orders were, the pyc- 
 nostyle, the systyle, the eustyle, 
 the diastyle, and the araeostyle. 
 
 In the Doric order they used 
 other intercolumniations, regu- 
 lating them by the triglyphs, of 
 which one was always to be placed 
 directly over the middle of each 
 column, so that they were either 
 systyle monotriglyph, of one dia- 
 meter and a half; diastyle, or 
 araeostyle : the Tuscan intervals 
 were exceedingly wide, some of 
 them being above seven diameters, 
 which, as the architraves were of 
 wood, was practicable. 
 
 Vitruvius intended the five inter- 
 columniations, mentioned in his 3rd 
 book, merely for the Ionic and Co- 
 rinthian orders ; the latter of which, 
 according to him, differed from the 
 former only in its capital; for, in the 
 second and seventh chapters of his 
 fourth book, he establishes other 
 intervals for the Doric and Tuscan 
 orders. Nevertheless, they have 
 employed these intercolumniations 
 in different orders. Palladio has 
 used the systyle in the Corinthian 
 
 240 
 
 and the araeostyle in the Tuscan 
 by which means the Corinthian 
 peristyle, of which the character 
 should be extreme delicacy ant 
 lightness, becomes twice as strong 
 and material as the Tuscan, o 
 which the distinguishing characte- 
 ristics ought to be extreme solidity 
 Interdentals. The space between two 
 
 dentals. 
 
 | Interlignium, in ancient architecture 
 the space between the ends of the 
 tie-beams. 
 Interpensivee, timbers in the roof ol 
 the cavaedium, extending in a dia- 
 gonal direction from the angles 
 made by the walls of the court to 
 the angles made by the junction ol 
 the beams supporting the roof. 
 Intrados, the soffit or under-surface 
 of an arch, as opposed to extrados. 
 In vacua, a void or empty space. 
 Invention, in painting, consists prin- 
 cipally in three things : first, the 
 choice of a subject properly within 
 the scope of art ; secondly, the sei- 
 zure of the most striking and ener- 
 getic moment of time, for represen- 
 tation ; and lastly, the discovery 
 and solution of such objects, and 
 such probable incidental circum- 
 stances, as, combined together, may 
 best tend to develope the story, or 
 augment the interest of the piece. 
 The cartoons of Raphael furnish 
 an example of genius and sagacity 
 in this part of the art. 
 Inverse, turned back or inverted ; op- 
 posed to direct. 
 Inverse ratio, when more requires 
 
 less, or less requires more. 
 Inverted arch, an arch of stone or 
 brick, with the crown downwards, 
 commonly used in the construction 
 of tunnels. 
 
 Iodine scarlet is a new pigment, of a 
 peculiarly vivid and beautiful co- 
 lour, exceeding even the brilliancy 
 of vermilion. It has received se- 
 veral false appellations, but is truly 
 an iodide or biniodide of mercury, 
 varying in degrees of intense red- 
 ness. It has the body and opacity 
 of vermilion, but should be used 
 
IOD 
 
 IRON. 
 
 IRQ 
 
 with an ivory palette-knife, as iron 
 and most rnetals change it to co- 
 lours varying from yellow to black. 
 
 Iodine yellow, ioduret of lead, is a 
 precipitate from an acid solution of 
 lead by an alkaline solution of 
 iodine, of a bright yellow colour, 
 which, from its active chemical affi- 
 nities, and the little experience of 
 its qualities in painting, is to be 
 employed with doubt and caution. 
 
 Ionic capital. The Greek architects 
 must have possessed much science 
 in the formation of curves of every 
 description. We cannot generate 
 the curve of the volute of an Ionic 
 capital but by approximation ; but 
 the inventors of the order must 
 have known how to generate this 
 and other curves in Greek architec- 
 ture, on fixed principles ; so must 
 the artist in vases, etc. Mr. Jop- 
 ling is said to have discovered the 
 true generic curve. 
 
 Ionic Order : this, says Palladio, " had 
 its origin in Ionia, a province of 
 Asia ; and we read that the famous 
 temple of Diana at Ephesus was 
 built of that order. The column, 
 with its capital and base, is nine 
 modules high ; and by a module 
 is understood the diameter of a 
 column below. The architrave, 
 frieze, and cornice, have the fifth 
 part of the height of the column. 
 When the columns are single, the 
 inter-columns are of two diameters 
 and a fourth part, and this is the 
 most beautiful and commodious 
 manner of all inter-columns, which 
 Vitruvius calls eustylos." 
 
 Amongst the ancients, the form 
 of the Ionic profile appears to 
 have been more positively deter- 
 mined than that of any other order ; 
 for in all the antiques at Rome, the 
 temple of Concord excepted, it is 
 exactly the same, and conformable 
 to the description which Vitruvius 
 has given of it. 
 
 Modern artists have likewise been 
 more unanimous in their opinions 
 upon the subject ; all of them, ex- 
 cepting Palladio and his imitators, 
 
 241 
 
 having employed the dentil cornice, 
 and the other parts of the profile, 
 nearly as they are found in the Co- 
 liseum, the temple of Fortune, and 
 the theatre of Marcellus. 
 
 In Palladio's works we meet with 
 three different Ionic entablatures, 
 all of them very beautiful. The 
 first is the true antique, which he 
 has made use of at the palace of 
 the Porti ; and in several doors and 
 windows of the Thiene and Val- 
 marana palaces, in Vicenza. The 
 second is a very judicious imitation 
 of the entablature in the temple of 
 Concord, and is executed by him 
 in the upper arcade of the basilica 
 in the same city. The third, which 
 is an invention of his own, being 
 the same with that in his book, he 
 has employed with some small dif- 
 ference at the Chiericato palace, at 
 the rotunda of Marchese Capra, 
 and in various others of his build- 
 ings in the Vicentine, or at Venice. 
 Iron, the most useful and the most 
 abundant of the metals, is found in 
 various conditions of ore in most 
 parts of the earth. Those ores 
 which are principally worked for 
 the production of the metal for 
 manufacturing purposes, are either 
 oxides or carbonates, that is. they 
 contain the metal in a state of 
 combination either with oxygen, 
 or with oxygen and carbonic acid. 
 The oxides are the best ores, and 
 are found in vast beds in S\veden : 
 the carbonates are inferior in point 
 of strength and ductility, and there- 
 fore require an extensive reduction. 
 They form the greater portion of 
 the iron ores of Britain. 
 
 The principal varieties of the ox- 
 ides of iron are, the magnetic; 
 the massive, found in the north of 
 Europe, and other parts of the 
 world ; the micaceous, found in the 
 lava of volcanoes, etc. ; and the 
 red and brown haematites, found in 
 Great Britain and Europe. The 
 principal varieties of the carbo- 
 nates are, the massive, found in 
 Great Britain and Ireland, Europe, 
 
IRQ 
 
 IRON. 
 
 IRQ 
 
 and America ; and also the argi^- 
 laceous, commonly known as clay 
 iron-stone, found abundantly in 
 beds and coal deposits in England, 
 Wales, and Scotland. 
 
 Besidestheoxides and carbonates 
 here enumerated, iron is found in 
 large quantities in combination with 
 sulphur; and the several compounds 
 thus formed are known as pyrites, 
 several varieties of which are found 
 in Norway, Sweden, Germany, Ame- 
 rica, and in many parts of England. 
 
 Various artificial oxides of this 
 metal are applied to medicine, dye- 
 ing, and other purposes in the arts. 
 
 The tenacity and strength of 
 iron are impaired by its adultera- 
 tion with foreign matters. Thus, 
 of the oxides and carbonates, those 
 are best in which the proportion 
 of the metal is great. These qua- 
 lities are further increased by fu- 
 sion, and by the mechanical pro- 
 cess of hammering; and this fact 
 points to the main distinction in 
 the kinds of iron as applied for 
 manufacturing purposes, viz. foun- 
 dry iron and forge iron. 
 
 In the manufacture of iron, the 
 first process is the reduction of the 
 iron-stone or ore, technically called 
 the mine, into the state of a metal. 
 This is done by fusion in a furnace, 
 with coke added to produce com- 
 bustion, and limestone to act as a 
 flux and assist the fusion of the ore. 
 An artificial current of air is neces- 
 sary to fuse the ore in these furnaces, 
 which are therefore called blast fur- 
 naces, and provided with tubes or 
 tuyeres, through the tapered noz- 
 zles of which strong currents of air 
 are delivered to the interior of the 
 furnace, the required velocity of the 
 blasts being sustained by steam or 
 other power. Formerly the air was 
 thus introduced at the same tempe- 
 rature as that of the external atmo- 
 sphere ; but a plan has for many 
 years been extensively adopted of 
 previously heating the air for the 
 blasts in separate vessels to a high 
 temperature, by which the fusion 
 
 242 
 
 of the ore is so powerfully assisted, 
 that the saving of fuel in the furnace 
 is many times greater than the 
 quantity used for the preparatory 
 heating of the air. Furnaces thus 
 supplied are termed hot-blast fur- 
 naces, and the product is called hot- 
 blast iron, while that made with un- 
 heated air is called cold-blast iron. 
 The cost of the process of reduc- 
 tion with the hot blast being so 
 much less than of that with the 
 cold blast, the ultimate value of the 
 former is of course also partly de- 
 pendent upon the quality of the 
 produce. On this head much differ- 
 ence of opinionhas often been mani- 
 fested, and with all the earnestness 
 usually displayed in the advocacy 
 of self-interest. The value of each 
 process must, no doubt, arise from 
 the completeness of the fusion pro- 
 duced, and the separation effected 
 between the iron and the impuri- 
 ties combined with it in the ore. 
 The hot-lplast furnace effects the 
 fusion more readily than the cold- 
 blast, but admits a larger combina- 
 tion of cinders with the ore ; and 
 the advantage which has been 
 taken of this facility of adulteration, 
 in order to reduce the cost of pro- 
 duction, has doubtless led to the 
 introduction into the market of 
 many qualities of hot-blast iron 
 which are inferior in strength to 
 that made with the cold blast. The 
 results of some of the most care- 
 fully conducted experiments which 
 have been made upon the strength 
 of cast-iron, and published in the 
 6th volume of the new series of 
 ' Memoirs of the Literary and Phi- 
 losophical Society of Manchester,' 
 show that the transverse strength 
 of the cold-blast iron tried was 
 about 2 per cent, greater than 
 that of the hot-blast. The experi- 
 ments here referred to were made 
 upon rectangular bars 1 inch square, 
 and 4 feet 6 inches long between 
 the supports. The mean average 
 breaking weights, placed at the 
 middle of these bars, were 
 
IRQ 
 
 Ibs. 
 
 In 21 samples of hot- 
 blast iron .... 445-5714 
 In 22 samples of cold- 
 blast iron .... 456*9090 
 The metal is allowed to flow 
 from the furnace into rude channels 
 formedonthe surface of the ground, 
 where it cools, and is taken up in 
 the form of rough bars about 3 feet 
 long, and each weighing nearly one 
 cwt., which are technically called 
 pigs. In the making of one ton of 
 pig-iron in Staffordshire, the fol- 
 lowing materials are used : 
 Coal, 2 tons 5 cwt. 
 If coke is used instead of coal, 
 
 1 ton 17 cwt. 
 Charred mine, or ore, 2 tons 
 
 5 cwt. to 2 tons 10 cwt. 
 Limestone, 13 cwt. to 16 cwt. 
 In the condition of pig-iron, the 
 metal forms the two staple de- 
 scriptions of foundry iron and of 
 forge iron, according to its quali- 
 ties, and the proportion of carbon 
 and oxygen which it contains. The 
 several sorts of pig-iron are consi- 
 dered to be six in number, and are 
 thus distinguished: Nos. 1, 2, and 
 3, foundry iron, of which the first 
 two are never used for forge iron. 
 No. 3, or dark grey, and also the 
 fourth quality known as bright iron, 
 are sometimes used for the foundry, 
 and sometimes for the forge. The 
 fifth and sixth sorts, known as 
 mottled iron and white iron, are 
 never used for the foundry. The 
 order here observed corresponds 
 with that of the proportion of car- 
 bon and oxygen mixed with each 
 kind of the iron, and also with thac 
 of the fluidity to which the metal is 
 reducible : it also corresponds with 
 the scale of their softness and 
 toughness. Thus, No. 1 has the 
 most carbon and oxygen, and the 
 white iron has the least. No. 1 is 
 the most fluid when melted, and the 
 white iron the least so. Again, No. 
 1 is the softest, and the white iron 
 the hardest ; and No. 1 is the tough- 
 est, while the white iron is the 
 
 IRON. IRQ 
 
 most brittle. But white iron is the 
 best adapted for conversion into 
 malleable iron, while Nos. 1 and 2, 
 foundry iron, contain so large a pro- 
 portion of carbon and oxygen, that 
 they are totally unfit to be manu- 
 factured into bars. 
 
 The conversion of pig-iron into 
 malleable iron is effected by ex- 
 tended processes, or subsequent to 
 those by which the ore has been 
 reduced to the form of pig. These 
 processes are as follow : 
 1. Refining. 2. Puddling, ham- 
 mering, and rolling, 3. Cutting 
 up, piling, and rolling; the 3rd 
 series of operations being re- 
 peated. 
 
 The refining is for the purpose 
 of separating a portion of the car- 
 bon from the pig, and is performed 
 in furnaces fitted with tuyeres for 
 supplying a blast of air to the 
 point of fusion. The metal run 
 from the refining moulds is exceed- 
 ingly brittle, and is then broken up 
 into small pieces, and committed 
 to the puddling or reverberatory 
 furnace, to undergo a further puri- 
 fication from the oxygen and car- 
 bon which remain after the process 
 of refining is accomplished. While 
 in this furnace, the mass into which 
 the pieces of refined metal become 
 clustered is worked and stirred 
 about by the workman or puddler, 
 until its thickness and tenacity are 
 so far increased that it may be 
 formed into lumps, or balls, which 
 the puddler does with tools adapt- 
 ed to the purpose. 
 
 The hammering or shingling is 
 performed upon the balls or blooms 
 of puddled iron, with a very heavy 
 hammer, worked by a cam-wheel, 
 and has the effect of improving the 
 solidity of the metal, and reducing 
 the balls into an oblong form, by 
 which they are better prepared for 
 the action of the rollers. 
 
 The rolls or rollers are fitted to- 
 gether in pairs, and so formed in 
 the periphery and arranged in size, 
 that open spaces are formed be- 
 
 243 
 
 M 2 
 
IRQ 
 
 IRON. 
 
 IRQ 
 
 tween them, through which the 
 metal is passed while hot ; and each* 
 succeeding pair of rollers present- 
 ing a smaller space, the iron which 
 is drawn through them becomes 
 proportionately reduced in size and 
 increased in length. 
 
 The metal has thus been convert- 
 ed from a hard, brittle, and readily 
 fusible substance into a malleable 
 bar, which is soft, tough, and very 
 difficult of fusion ; but it is still far 
 from fit for the smith's use, being 
 to a great extent unsound in struc- 
 ture, imperfect in tenacity, and 
 irregular on the surface. 
 
 The third set of processes is 
 now conirnenced by cutting up the 
 puddled bars into lengths with 
 powerful shears. These lengths, of 
 various dimensions, according to 
 the sized bars to be produced, are 
 carefully piled up and heated in 
 another furnace similar to the pud- 
 dling furnace, and which is called 
 the balling furnace. In this the 
 bars are simply heated to a degree 
 which admits of their becoming 
 welded together in the pile and 
 adapted for reduction to the form 
 of finished bars in the rolls. 
 
 The rolling is the last operation 
 in the making of bar-iron. The 
 metal is dn-vn successively through 
 a series 01 rollers, that is, between 
 the peripheries of each pair of 
 rollers, and thus gradually reduced 
 in size, increased in length, and 
 freed from the cinder and other 
 impurities which remain after the 
 puddle - rolling has been per- 
 formed. 
 
 The last set of operations is some- 
 times repeated in producing iron 
 for superior purposes. The pro- 
 cesses here described will give a 
 general idea of the manufacture of 
 iron from the native ore into the 
 form of malleable bars ; and it may 
 be readily conceived how an exten- 
 sion and variation of the process of 
 rolling may be made to produce the 
 several other forms in which this 
 metal is prepared for the construc- 
 
 244 
 
 tions of the engineer, the smith, 
 and the machinist. 
 
 As varieties of bar-iron may be 
 mentioned, L, or angle-iron ; T, 
 or tee-iron ; and H, or deck-beam 
 iron ; which are prepared in several 
 sizes for the construction of roofs, 
 iron vessels, etc. The malleable 
 rails used for railways are also 
 produced by an arrangement of 
 rollers. 
 
 Boiler - plate iron, sheet - iron, 
 hoop-iron, and nail rod-iron, are 
 produced from the form of bars by 
 the processes of heating and rolling, 
 or hammering, as required. Boiler- 
 plates require, according to the 
 desired strength and size, several 
 repetitions of heating, hammering, 
 and rolling. Sheet-iron is distin- 
 guished from boiler-plate by being 
 thinner; hoop-iron is rolled ih the 
 same manner as the bars, but be- 
 tween rollers without grooves in 
 their edges, the requisite thickness 
 being effected by successive pas- 
 sages through the rollers, which are 
 brought nearer to each other at 
 each process, by means of adjust- 
 ing screws. Nail rod-iron is rolled 
 in thin bars, which are, while still 
 hot, passed between steel cutters 
 that slit them up mto the form of 
 small rods, which, although rough, 
 are well fitted to be manufactured 
 into nails. 
 
 A very useful form of sheet-iron, 
 which should be noticed, is that of 
 corrugated iron, which is produced 
 by passing the sheets between 
 rollers having grooved peripheries. 
 By this form, the strength or stiff- 
 ness of the sheet is so much in- 
 creased, that sheet-iron thus formed 
 may be usefully applied to a great 
 variety of purposes for which it is 
 otherwise, owing to its thinness 
 and pliability, utterly inadequate. 
 
 By the combustion of charcoal 
 with the coke, and the adaptation 
 of a peculiar furnace in the process 
 of smelting, Mr. Clay has succeeded 
 in producing malleable iron direct 
 from the ore, and thus materially 
 
IRQ 
 
 ITALIAN ARCHITECTURE. 
 
 ITA 
 
 reducing the series of processes 
 here described. The results thus 
 brought out are of a very interest- 
 ing character, and promise to ac- 
 quire a great practical value. Mr. 
 Bessemer has patented most suc- 
 cessfully some inventions for making 
 iron and steel without the aid of 
 puddling. See ' Engineer's Pocket 
 Book ' for description. 
 
 Iron. Moses forbade the Hebrews the 
 use of any stones to form the altar 
 of the Lord, which had been in any 
 manner wrought with iron ; as if 
 iron communicated pollution. He 
 says, the stones of Palestine are of 
 iron, that is, of hardness equal to 
 iron, or, being smelted, they yielded 
 iron. " An iron yoke " is a hard 
 and insupportable dominion. " Iron 
 sharpeneth iron," says the Wise 
 Man, "so a man sharpeneth the 
 countenance of his friend :" the pre- 
 sence of a friend gives us more 
 confidence and assurance. God 
 threatens his ungrateful and per- 
 fidious people with making the 
 heavens iron, and the earth brass ; 
 that is, to make the earth barren, 
 and the air to produce no rain. 
 Chariots of iron are chariots armed 
 with iron, with spikes and scythes. 
 
 Iron ship building, a new and a 
 most successful mode of construc- 
 tion of ships in the hull of iron, 
 both for merchant and war pur- 
 poses, and for passenger vessels, 
 upon any scale of dimensions. See 
 vol. 54, John Grantham on Iron 
 Ship Building, in the 'Rudimen- 
 tary ;' also separately, with ' Atlas 
 of Practical Examples' in large en- 
 gravings. 
 
 Iron-stone, iron-bound stone, in colour 
 of a bluish grey : it contains but 
 little iron, and is hard to work. 
 
 Iron-stone has the appearance of 
 rusty-black shale, and, when laid 
 together in large heaps, is so com- 
 bustible that it ignites, leaving a 
 calx of 60 per cent, of iron. It 
 abounds in Scotland. Common 
 iron-stone is also very abundant in 
 connection with coal, and in former 
 
 245 
 
 times formed the principal supply, 
 which induced the foundation of 
 the Carron Iron-works. 
 
 Iron-wood is imported from the Bra- 
 zils, the East and West Indies, and 
 other countries, in square and 
 round logs, 6 to 9 inches and up- 
 wards through. Its colours are 
 very dark browns and reds : some- 
 times it is streaked, and generally 
 straight-grained ; used principally 
 for ramrods, turnery, etc., and is 
 extremely hard. 
 
 Iron yellow, jaune de fer, or jaune de 
 Mars, etc., is a bright iron ochre, 
 prepared artificially, of the nature 
 of sienna earth. The colours of 
 iron exist in endless variety in na- 
 ture, and are capable of the same 
 variation by art, from sienna yel- 
 low, through orange and red, to 
 purple, brown, and black, among 
 which are useful and valuable dis- 
 tinctions, which are brighter and 
 purer than native ochres. 
 
 Irrigation, watering the ground. 
 
 Isochronism, in mechanics, the per- 
 forming of several things in equal 
 times ; such as the vibrations of 
 the pendulum. 
 
 fsodomon, a building every way 
 straight. 
 
 Isodomos, in Greek architecture, ma- 
 sonry cut and squared to the same 
 height, so that, when laid, the 
 courses were all regular and equal. 
 
 Isometrical, projections and drawings 
 so termed. 
 
 Isoperimetrical, in geometry, such 
 figures as have equal perimeters or 
 circumferences. 
 
 Isosceles, in geometry, a triangle that 
 has only two sides equal. 
 
 Isothermal, in chemistry, equal heat. 
 
 Italian. Architecture,^, style now much 
 appreciated, not only in Italy, but 
 in England and France, was first in- 
 troduced at the revival of classical 
 architecture, and was subsequently 
 much improved, and adapted to 
 modern refinement. The architec- 
 ture of Venice, Florence, Genoa, 
 Rome and Sicily, afford to the 
 architect a complete library of ex- 
 
ITA 
 
 ITALIAN ARCHITECTURE. 
 
 ITA 
 
 amples by the possession of tha 
 several works published of the ar- 
 chitecture of the palaces and man- 
 sions of these cities. 
 
 Respecting buildings originally 
 erected in Italy, Mr. Jos. Gwilt has 
 thus written : 
 
 The Romans followed the Greeks 
 in the general form of their temples, 
 but added to their splendour by a 
 greater richness of detail, and the 
 employment of other orders. For 
 the simple steps on which the Greek 
 temple was elevated, they substi- 
 tuted pedestals, and added a base to 
 the Doric order. The climate pre- 
 scribed a more elevated pediment ; 
 but the luxury of the people was 
 the cause of the preference given to 
 the richer orders of architecture. 
 
 TEMPLES, BRIDGES, AQ.UEDUCTS, 
 COLUMNS, THEATRES, ETC. 
 
 The chief temples of Rome were 
 the Capitol, built on the Tar- 
 peian or Capitoline mount, by Tar- 
 quinius Superbus. (See Capito- 
 lium.) No traces of it at present 
 remain. The edifice of the Capitol 
 was about 200 feet square, and con- 
 tained three temples, consecrated 
 to Jupiter, Minerva, and Juno. On 
 the Capitol were also the temples 
 of Terminus and Jupiter Feretrius, 
 and the cottage of Romulus. 
 
 The Pantheon, built by Agrippa, 
 the son-in-law of Augustus, and 
 dedicated to Mars and Venus, or 
 more probably, from its name, to 
 all the gods. Pope Boniface IV. 
 consecrated it in honour of the Vir- 
 gin Mary and All Saints, A.D. 607. 
 It is now generally known by the 
 name of the ' Rotunda ; ' its dia- 
 meter between the axes of the 
 columns is 147 feet: like most of 
 the ancient buildings, it has fallen 
 a prey to the spoiler. The Balda- 
 chino in St. Peter's is indebted for 
 its materials to the Pantheon of 
 Agrippa. 
 
 The temple of Apollo, on the 
 Palatine hill, was built by Augus- 
 tus : a temple of Diana stood on 
 the Aventine. 
 
 246 
 
 The temple of Janus was sup- 
 posed to have been built by Romu- 
 lus ; that of Romulus by Papirius. 
 Of those to the Sun and Moon, 
 Fortuna Virilis, Vesta, Minerva 
 Medica, Neptune, Antoninus and 
 Faustina, Concord, Jupiter Stator, 
 and most particularly of the tem- 
 ple of Peace, considerable remains 
 are fortunately still in being. The 
 three magnificent arches now stand- 
 ing of that last named, though of 
 themselves majestic, convey but a 
 faint idea of its pristine splendour. 
 Of the temple of Jupiter Stator, 
 whose columns, capitals, and en- 
 tablatures were a perfect example 
 of the Corinthian order, only three 
 columns are in existence. The re- 
 mains of the temples of Antoninus 
 Pius, Claudius, Hercules, Jupiter 
 Tonans, Isis, Romulus, and Venus 
 and Cupid, are still interesting. 
 
 No vestiges exist of the temples 
 dedicated to Saturn, Juno, Mars 
 bis Ultor, in the forum of Augus- 
 tus, nor of numberless others that 
 adorned the city. 
 
 The temples of Balbec and Pal- 
 myra are the last of the ancient 
 Roman works that can lay claim to 
 the appellation of classic architec- 
 ture. In these, invention seems to 
 have found its limits. The repro- 
 duction and new adaptation of their 
 detail is all that has been done by 
 following artists. 
 
 The Romans, not content with 
 the quadrilateral temple, made use 
 of the circular form, as in the Pan- 
 theon, temple of Vesta, and others 
 at Rome, and that of the Sibyl at 
 Tivoli. Except their theatres, and 
 the little work generally known by 
 the name of the Lantern of Demo- 
 sthenes, the Greeks have left no 
 buildings on a circular plan. 
 
 After the time of Diocletian, a 
 new style prevailed in Italy. The 
 basilica3 of Constantine, as they ex- 
 isted previous to their restoration, 
 and, in short, almost all the first 
 Christian churches, were built out 
 of the materials which the old tern- 
 
ITA 
 
 ITALIAN BUILDINGS. 
 
 ITA 
 
 pies afforded in abundance. The 
 basilica of S. Paolo fuori le Mura 
 still contains a large portion of the 
 columns which had originally be- 
 longed to the mausoleum of Adrian. 
 The style of these basilicae may 
 with propriety be termed Roman- 
 Gothic. This was followed by the 
 Greek-Gothic, of which examples 
 may be found in most of the cities 
 of Italy, as in St. Mark at Venice, 
 the cathedral at Pisa (built by 
 Buschetto da Dulichio, a Greek ar- 
 chitect of the llth century), and 
 in the baptistery and leaning cam- 
 panile of the same city : specimens 
 abound also in Bologna, Siena, Ve- 
 nice, Viterbo, Rome, etc. They are 
 chiefly the works of Nicola da Pisa 
 and his scholars. 
 
 At the time that the famous ca- 
 thedral of Milan, the perfection of 
 the Lombard-Gothic style, was in 
 hand, Brunelleschi was advancing 
 a step further, and had begun the 
 restoration of classical architecture 
 in the great cupola of Sta. M iria 
 del Fiore at Florence; his prototype 
 seeming to have been the temple 
 of Minerva Medica, to which his 
 work has sufficient resemblance to 
 justify the allusion to it. He suc- 
 ceeded in his enterprise, and thus 
 gave a death-blow to the Italian- 
 Gothic of all sorts. L. B. Alberti, 
 Bramante, and Fra Giocondo re- 
 stored the use of the orders; Michael 
 Angelo, Raphael, Sangallo, Pal- 
 ladio, and Scamozzi completed the 
 change; the church of St. Peter 
 rose, and every little city began to 
 provide itself with a Duomo. 
 
 The fora of the ancients were 
 large squares surrounded by por- 
 ticoes, which were applied to dif- 
 ferent purposes. Some parts of 
 them answered for market-places, 
 other parts for the public meetings 
 of the inhabitants, still other parts 
 for courts of justice. The forum 
 also occasionally afforded accom- 
 modation for the shows of gladi- 
 ators. Rome contained seventeen 
 fora, of which fourteen were used 
 
 247 
 
 for the show and sale of goods, 
 provisions, and merchandise, and 
 were called Fora Venalia ; the other 
 three were appropriated for civil 
 and judicial proceedings, and hence 
 called Fora Civilia et Judicialia. 
 Of the latter sort was the forum 
 of Trajan. 
 
 The forum of Julius Caesar was 
 far more splendid than the Forum 
 Romanum : it cost upwards of 
 800,000 sterling, and stood in 
 the neighbourhood of the Campo 
 Vaccino, to the east of the temples 
 of Peace and of Antoninus and 
 Faustina. 
 
 In the vicinity of that last named 
 was the forum of Augustus : the 
 temple of Mars bis Ultor decora- 
 ted the centre of it. 
 
 The forum of Nerva, called also 
 the Forum Transitorium, begun by 
 Domitian, was decorated by Alex- 
 ander Severus with colossal statues 
 of the Emperors, some of which 
 were equestrian. Parts of this forum 
 are still in tolerable preservation. 
 
 The forum of Trajan, which has 
 lately been accurately traced by 
 means of veryextensiveexcavations, 
 and the demolition of a great num- 
 ber of houses, was by far the most 
 magnificent. The Trajan column 
 formed one of its ornaments : the 
 architect was Apollodorus, and its 
 situation was between the forum of 
 Nerva and the Capitol. 
 
 The basilica (a term now applied 
 to the cathedrals of Rome) was 
 originally a court of justice. Like 
 the forum, it was furnished with 
 shops for the merchants and bank- 
 ers. In the place called the Comi- 
 tium were four basilicse,' viz. that 
 of Paulus, the Basilica Opimia, 
 Julia (built by Vitruvius), and Por- 
 tia: besides thp;e, the most impor- 
 tant were those of Sicinius, Sem- 
 pronius, Caius and Lucius, Antoni- 
 nus Pius, and the Basilica Argen- 
 tariorum, or of the goldsmiths. 
 Some of less consideration stood 
 in the vicinity of the Forum Ro- 
 manum. 
 
ITA 
 
 ITALIAN BUILDINGS. 
 
 ITA 
 
 The modern halls of Italy in 
 some respects answer the purpose 
 of the ancient basilicae. Those 
 most worthy of notice are at Venice, 
 Vicenza, Padua, and Brescia. 
 
 Near the Tarpeian rock stood 
 the famous prison built by Ancus 
 Martius, which was afterwards call- 
 ed Tullianum, from the additions 
 thereto by Servius Tullius. The 
 Curia Hostilia, where the Senate 
 frequently met, was the Comitium : 
 at its entrance, close to the tem- 
 ple of Saturn, was the Milliarium 
 Aureum, the central point from 
 which all the roads to the different 
 provinces diverged, and near to 
 which ran the gallery constructed 
 by Caligula, which joined the Pa- 
 latine and Capitoline hills. It was 
 constructed with eighty columns of 
 white marble. 
 
 The porticoes of Pompey, Au- 
 gustus, Domitian, and Nero were 
 the most celebrated of Rome. The 
 first-named afforded a refreshing 
 retreat from the sun's rays. The 
 portico of Augustus was construct- 
 ed with columns of African mar- 
 ble, and was ornamented with fifty 
 statues of the Danaides. Those 
 of Nero, three in number, each 
 three miles in length, were called 
 Milliarise, on account of their ex- 
 traordinary dimensions, forming a 
 part of his palace. 
 
 The pyramidal form was gene- 
 rally applied to tombs. In the he- 
 roic ages, a cone of earth, whose 
 base was of considerable extent, 
 covered the ashes of the person to 
 be commemorated. This was the 
 practice of the early ages. Men 
 were, however, desirous of triumph- 
 ing over death, and the Pyramids, 
 as well as numberless other monu- 
 ments, the names of whose authors 
 are now lost, have proved the 
 vanity of their desires : the memory 
 of man must depend upon " deeds 
 done in the flesh." 
 
 The pyramid of Caius Cestius, a 
 trifle conipared with those of Egypt, 
 is yet enormous, considering the in- 
 
 248 
 
 dividual to whose memory it was 
 erected. The tower of Cecilia Me- 
 tella, called the Capo di Bove, on 
 the Appian way, is a beautiful speci- j 
 men of art. The Appian, Flami- 
 nian, and Latin ways exhibit num- 
 berless sepulchres of an interest- 
 ing nature. Those which are found 
 with the inscription D.M., or Diis 
 Manibus, contain the ashes of the 
 persons whose names they bear ; 
 but theothers are mostly cenotaphs, 
 the bodies having been deposited 
 elsewhere. 
 
 Triumphal arches may be rec- 
 koned among the luxuries of the 
 Romans. Nothing which could tend 
 to perpetuate the fame of the con- 
 queror was omitted in the design. 
 Some of them were with two, some 
 with three passages. The richest 
 were on the Triumphal way. Those 
 which also served as gates generally 
 consisted of two openings, one for 
 the carriages passing out of, the j 
 other for carriages passing into the 
 city. With the Greeks, a trophy 
 erected on the field of battle was 
 held of equal importance with the 
 triumphal arch of the Romans, and 
 a breach was sometimes made in 
 the walls to admit the entry of the 
 conqueror. 
 
 The Roman Senate received the 
 conqueror at the Porta Capena, 
 near the Tiber, which was the en- 
 trance to the city from the Appian 
 way. 
 
 The arch of Augustus at Rimini 
 has but a single passage, about 33 
 feet wide : it was crowned with a 
 pediment, contrary to the usual 
 practice. This was a beautiful spe- 
 cimen, but it is much mutilated. 
 
 That called the arch of the Gold- 
 smiths at Rame is a curious exam- 
 ple. It is very small, with a single 
 opening, whose crowning is a flat 
 lintel. 
 
 The arch of Augustus at Susa, a 
 smalltown just on the Italian side of 
 Mount Cenis,is extremely elegant. 
 
 Those of Aurelian and Janus are 
 more singular than beautiful. 
 
ITA 
 
 ITALIAN BUILDINGS. 
 
 ITA 
 
 The arch of Pola in Istria is only 
 curious on account of its affording 
 a justification of the use of coupled 
 columns, were the authority of the 
 ancients necessary for the purpose : 
 it was erected by Salvia Posthuma 
 in honour of Sergius Lepidus and 
 his two brothers. 
 
 The arch of Trajan at Ancona is 
 still in tolerable preservation. It 
 has long since been stripped of its 
 bronze ornaments, but their absence 
 has not impaired its elegant pro- 
 portions. 
 
 The arches of Titus at Rome 
 and Trajan at Benevento bear con- 
 siderable resemblance to each other. 
 That of Gavius at Verona, called 
 ' del Castel Vecchio,' no longer ex- 
 ists. The precepts of Vitruvius 
 have been confronted with his prac- 
 tice in this arch ; but Vitruvius 
 Cerdo, not Vitruvius Pollio, was 
 the architect. 
 
 The arches of Septimius Severus 
 and of Constantine are with three 
 openings. The latter is decorated 
 with ornaments shamefully stripped 
 off from the arch of Trajan, which 
 from their absurd application, ren- 
 der the barbarism of the robber 
 more disgusting. 
 
 Rome formerly contained eight 
 bridges. The Pons Sublicius, built 
 by Ancus Martius near the Tiber, 
 was of timber, so framed as to re- 
 quire no iron bolts or ties for its 
 security. It stood at the foot of 
 the Aventine, and was that which 
 Horatius Codes defended. It was 
 replaced by one of stone by ./Emilius 
 Lepidus, and then had the name of 
 JEmilianus. Tiberius afterwards 
 repaired it. Finally, Antoninus 
 Pius rebuilt it of marble, whence it 
 obtained the name of Marmoratus. 
 
 The Pons Triumphalis, near the 
 Vatican, is in ruins : few vestiges 
 of it exist. Those who triumphed 
 passed over this bridge in their way 
 "to the Capitol. 
 
 The Pons Fabricius led to an 
 island in the Tiber : it is now called 
 Quattro Capi. That which led 
 
 from the island to the right bank 
 of the river was called Pons Cestius 
 or Esquilinus : it was rebuilt during 
 the reigns of the emperors Valen- 
 tinian, Valens, and Gratian. 
 
 Pons Janiculi, so called because 
 it led to the Janiculum, and now 
 known by the name of Ponte Sisto 
 (from having been restored by Six- 
 tus IV.), was of marble, and built 
 by Antoninus Pius. 
 
 Pons JElius, built by Julius Adri- 
 anus, is still in existence. It is 
 situated close to the mausoleum of 
 Adrian. This having changed its 
 name into that of Castel St. Angelo, 
 the bridge has acquired a corre- 
 sponding appellation. 
 
 The Pons Milvius, now Ponte 
 Molle, is a little way out of the city, 
 on the road to Florence. On this 
 bridge Cicero arrested the ambas- 
 sadors of the Allobroges, and in its 
 vicinity Constantine defeated Max- 
 entius. 
 
 Pons Senatorius, or Palatinus, is 
 partly remaining, close to the Pa- 
 tine mount. 
 
 Ponte Salaro is over the Teve- 
 rone, about three miles from Rome. 
 
 The spans of the arches are gene- 
 rally but small ; yet there are some 
 few magnificent exceptions, as in 
 the Ponte del Castel Vecchio at 
 Verona. This consists of three 
 arches, the largest of which is 170 
 feet span ; its two other arches are 
 smaller: they diminish from the 
 city, the left bank of the river being 
 considerably lower than the right. 
 The bridge built by Augustus over 
 the Nar, near Narni, on the Flami- 
 nian way, was a single arch of 150 
 feet span. In the later times of the 
 city, bridges were decorated with 
 trophies, colossal statues, triumphal 
 arches, and the like. Such was the 
 case with the Pons ^Elius and the 
 bridge of Augustus at Rimini. 
 
 The country round Rome is co- 
 vered with the remains of aque- 
 ducts, some of which conveyed the 
 water to Rome from a distance of 
 more than 60 miles. 
 
 249 
 
 M 3 
 
[TA 
 
 ITALIAN BUILDINGS. 
 
 ITA 
 
 The first aqueduct (Aqua Appia) * 
 was built, according to Diodorus, 
 by Appius Claudius, in the year of 
 the city 441. The water which it 
 supplied was collected from the 
 neighbourhood of Frascati, and its 
 summit was about 100 feet above 
 the level of Rome. 
 
 The second (Anio Vetus) was 
 begun forty years after the last- 
 named, by M. Curius Dentatus, and 
 finished by Fulvius Flaccus : it was 
 supplied from the country beyond 
 Tivoli. Near Vicovaro it is cut 
 through a rock upwards of a mile 
 in length, in which part it is 5 feet 
 high and 4 feet wide. The water 
 of this aqueduct was not good, and 
 therefore only used for the most 
 ordinary purposes. 
 
 The third (Aqua Martia) was 
 supplied from a fountain at the ex- 
 tremity of the mountains of the 
 Peligni. The water entered the 
 city by the Esquiline gate. This 
 aqueduct was the work of Quintus 
 Martius. 
 
 The fourth (Aqua Tepula) was 
 supplied from the vicinity of Fras- 
 cati. 
 
 The fifth (Aqua Julia) was about 
 six miles long, and entered the city 
 near the Porta Esquilina. 
 
 The sixth (Aqua Virginis) was 
 constructed by Agrippa thirteen 
 years after that immediately pre- 
 ceding. Its summit, in the terri- 
 tory of Tusculum, was about eight 
 miles from Rome, which it entered 
 by the Pincian gate. This water 
 still bears its ancient appellation, 
 being called Acqua Vergine. 
 
 The seventh (Aqua Alsietina, 
 called also Augusta, from the use 
 to which Augustus intended to ap- 
 ply it for supplying his Naumachia) 
 was brought from the lake whose 
 name it bears. 
 
 The eighth (Aqua Claudia), whose 
 summit is about forty miles from 
 Rome, was begun by Caligula, and 
 completed by Claudius. It enters 
 the city at the Porta Nevia, near 
 the Esquiline mount. The quality 
 
 of the water which this aqueduct 
 supplies is better than that of any 
 of the others. 
 
 The ninth (Anio novus, to dis- 
 tinguish it from the second-named 
 water) was begun and finished by 
 the same persons as the last-men- 
 tioned. It is the water of the Anio, 
 which, being exceedingly thick and 
 muddy after the rains, is conveyed 
 into a large reservoir at some little 
 distance from Rome, to allow the 
 mud to subside. 
 
 The Acqua Felice is modern, and 
 was erected by Sixtus V. in 1581. 
 The Popes have, from time to 
 time, been at considerable pains 
 and expense in repairing and re- 
 newing the aqueducts ; but the 
 quantity of water delivered is con- 
 stantly diminishing. In the ancient 
 city, the total sum of the areas of 
 the different pipes (which were 
 about an inch in diameter) through 
 which the above immense quantity 
 of water was delivered, amounted 
 to about 14,900 superficial inches; 
 but the supply was subsequently 
 reduced to 1170. 
 
 The waters were collected in re- 
 servoirs called castella, and thence 
 were conveyed through the city in 
 leaden pipes. The keepers of the 
 reservoirs were called castellani. 
 Agrippa alone built thirty of these 
 reservoirs during his sedileship. 
 There are five modern ones now 
 standing in the city : one at the 
 Porta Maggiore, Castello dell' Ac- 
 qua Giulia, dell' Acqua Felice, dell' 
 Acqua Paolina, and that called the 
 Fountain of Trevi. 
 
 In later times, the bath was al- 
 ways used by the Romans before 
 they went to their supper. The 
 rich generally had hot and cold 
 baths in their own houses ; and it 
 was not till the time of Augustus 
 that the baths assumed an air of 
 grandeur and magnificence. They 
 were called Thermae, that is, hot 
 baths, though the same pile of 
 building always contained cold as 
 well as hot baths. Different au- 
 
ITA 
 
 ITALIAN BUILDINGS. 
 
 ITA 
 
 thors have reckoned as many as 
 800 public baths in Rome. The 
 chief were those of Agrippa, Nero, 
 Titus, Domitian, Caracalla, Anto- 
 ninus, and Diocletian. Their ves- 
 tiges indicate the amazing magnifi- 
 cence of the age in which they 
 were erected. The pavements were 
 mosaic, the vaulted ceilings were 
 gilt and painted, and the walls in- 
 crusted with the richest marbles. 
 Some of the finest and best pre- 
 served remains of ancient Greek 
 sculpture have been restored to light 
 from these edifices. It was from 
 these that Raphael took the hint 
 for his fantastic decorations of the 
 Vatican, and the first restorers of 
 art drew their resources. 
 
 Dramatic entertainments were 
 first introduced at Rome in the 
 391st year of the city. In ancient 
 times the people stood during the 
 performance. For a considerable 
 period the theatres were mere tem- 
 porary buildings constructed of 
 wood. The most splendid of these 
 upon record was that of Marcus 
 jEmilius Scaurus : it was magnifi- 
 cently decorated, and was capable 
 of containing 80,000 persons. 
 
 It was in Pompey's second con- 
 sulship that the first stone theatre 
 was erected : this accommodated 
 40,000 spectators. To avoid the 
 animadversions of the Censors (for 
 the magistracy did not yet sanction 
 theatrical exhibitions), he dedicated 
 it to Venus. 
 
 Several other theatres afterwards 
 arose : that of Marcellus can still 
 be distinctly traced, and part of the 
 circular faade, in tolerable pre- 
 servation, is singularly elegant. 
 The theatre of Balbus was also of 
 considerable celebrity. 
 
 The theatres were open at top 
 to the heavens ; but in times of rain 
 or excessive heat, means were pro- 
 vided for covering them with a 
 species of cloth awning, by which 
 the inclemency of the weather 
 might be wholly or partially exclu- 
 ded. Their general form on the plan 
 
 251 
 
 was that of the letter D. The seats 
 (gradus} rose behind each other, 
 like steps. The front row was as- 
 signed for the use of the senators 
 and the ambassadors of foreign 
 states. Fourteen rows behind this 
 were reserved for the equites, and 
 the rest were open for the public 
 generally. The beautiful Olympic 
 theatre, by Palladio, at Vicenza, 
 was formed on the model of the 
 ancient Roman theatres, and gives 
 one an excellent idea of their 
 effect. 
 
 Like the theatres, amphitheatres 
 were at first constructed of wood, 
 and were only temporary. The first 
 amphitheatre of stone was built by 
 Statilius Taurus, at the desire of 
 Augustus. 
 
 Of all the monuments of anti- 
 quity, none is capable of creating 
 such sublime sensations in the mind 
 as the stupendous amphitheatre 
 generally called the Coliseum. It 
 was commenced in tne time of 
 Vespasian, and completed by Titus. 
 The plan of it is oval, and its ac- 
 commodation was for 87,000 spec- 
 tators, who could enjoy the exhibi- 
 tions therein without crowdingeach 
 other. The part in which the gladi- 
 ators fought was at the bottom, and 
 was called the arena, from being 
 usually covered with sand to absorb 
 the blood spilt in the savage con- 
 flicts for which it was used. The 
 arena was encircled by a wall, called 
 Ihe podium, which projected at top. 
 The podium was fifteen or sixteen 
 feet in height: immediately round 
 it sat the senators and foreign am- 
 bassadors. As in the theatres, the 
 seats rose at the back of each 
 other : fourteen rows in the rear of 
 the podium being allotted to the 
 equites, and the remainder to the 
 public generally, who sat on the 
 bare stone ; but cushions were pro- 
 vided for the senators and equites. 
 Though open to the sky, the build- 
 ing was occasionally covered by 
 means similar to those used in the 
 theatres. 
 
ITA 
 
 ITALIAN BUILDINGS. 
 
 ITA 
 
 The amphitheatre at Verona i^ 
 still in excellent preservation. 
 
 The Naumachise, or buildings for 
 the exhibition of sham naval com- 
 bats, were somewhat similar on 
 their plans to the circi, to which 
 purpose also sometimes these latter 
 were appropriated. The amphithe- 
 atres were, moreover, occasionally 
 used for the same sort of display. 
 Those of Augustus and Domitian 
 were the most magnificent. 
 
 The circus was a long narrow 
 building, whose length was to its 
 breadth generally as five to one: 
 it was divided down the centre by 
 an ornamented barrier, called the 
 spina. These buildings were used 
 for the celebration of games, racing, 
 etc., sometimes also for making 
 harangues to the people. 
 
 The first circus of stone is attri- 
 buted 1 1 Tarquin, and was situated 
 between the Palatine and Aventine 
 mounts. 
 
 The Circus Maximus was much 
 improved and altered by Julius 
 Caesar, who supplied it with water 
 for the purpose of occasionally 
 using it as a naumachia. Augustus 
 made great additions to it, deco- 
 rating it with the famous obelisk 
 which now stands in the Piazza del 
 Popolo, where it was placed by 
 Fontana in the year 1589, during 
 the pontificate of Sixtus V. Being 
 much dilapidated, it was repaired 
 under Antoninus, and afterwards 
 embellished with a second obelisk, 
 which has found a resting-place in 
 front of the church of St. John 
 Lateran, where it was set up by 
 the same Fontana. No vestiges of 
 this circus remain. 
 
 The circus of Flaminius, in the 
 vicinity of the Pantheon of Agrippa, 
 was of considerable dimensions, 
 and very magnificent. 
 
 The Circus Agonalis occupied 
 the site of what is now known by 
 the name of the Piazza Navona. 
 
 The circus of Nero, upon a part 
 whereof some portion of the basi- 
 lica of St. Peter is seated, was a 
 
 252 
 
 splendid building. The obelisk 
 now standing in the open circular 
 piazza before St. Peter's belonged 
 to this circus. 
 
 Those of Florus, Antoninus, and 
 Aurelian, are no longer even in 
 ruins ; but that of Caracalla is suf- 
 ficiently perfect to trace its plan 
 and distribution. It was 738 feet 
 in length. 
 
 The streets, in the time of Au- 
 gustus, were narrow and irregular. 
 After the great fire in Nero's reign, 
 the city was rebuilt with greater 
 splendour. The streets were then 
 set out straight, and considerably 
 broader than before. Those houses 
 wherein several families dwelt were 
 called imula>. Domus was the ex- 
 pression for a house occupied by 
 one family only. 
 
 We know little of the form of the 
 Roman houses, though Vitruvius 
 has described at sufficient length 
 the different apartments of which 
 they consisted. 
 
 The small houses discovered in the 
 ruins of Pompeii can bear but little 
 if any resemblance to the houses of 
 the opulent inhabitants of Rome. 
 The most celebrated were those of 
 the Gordians, P. Valerius Publicola, 
 Caesar, Sallust, Mecajnas, Cicero, 
 Verres, Augustus, and Lucullus. 
 The Domus Aurea of Nero was 
 probably the most magnificent in 
 Rome. * The villa of Adrian, at 
 Tivoli, was so extensive, that it al- 
 most deserved the name of a city. 
 Immense ruins of the palaces of 
 the Caesars are still to be seen. 
 
 Rome was decorated with num- 
 berless pillars. The most remark- 
 able are fortunately in an excellent 
 state of preservation, namely, those 
 of Trajan and Antoninus. 
 
 The column of Trajan stood in 
 that emperor's forum : it is about 
 12 feet in diameter at its base, and 
 (including the pedestal) is about 
 125 feet in height. The ascent to 
 the gallery on the top of the abacus 
 of its capital is by 185 steps, each 
 2 feet 9 inches long, winding round 
 
ITA 
 
 ITALIAN ARCHITECTURE. 
 
 ITA 
 
 the column, and lighted by 40 open- 
 ings. A colossal statue of Trajan 
 formerly crowned the top ; but St. 
 Peter has long since deposed the 
 Emperor. 
 
 The column of Antoninus is 176 
 feet high, its number of steps 106, 
 with 56 openings for the admission 
 of light. Sixtus V. caused its pe- 
 destal to be cased, when, in 1589, 
 the pillar was under repair. It was 
 this pontiff who elevated St. Peter 
 to his situation, as well on this as 
 on the Trajan column. 
 
 The great sewers of Rome are 
 reputed to have been the work of 
 Tarquinius Priscus. The Cloaca 
 Maxima, which still carries some of 
 the filth and waste water of Rome 
 into the Tiber, was the work of 
 Tarquinius Superbus. 
 
 The public ways were not only 
 some of the most stupendous, but 
 also the most useful of the Roman 
 works. 
 
 The first road which the Romans 
 paved was the Via Appia, so called 
 because it was executed by order 
 of Appius Claudius. He carried it 
 as far as Capua, whence it was af- 
 terwards continued to Brundusium 
 in all, a distance of 350 miles. 
 It is still entire in many places, 
 though more than twenty centuries 
 have elapsed since its construction. 
 It was properly called ' Regina 
 Viarum.' 
 
 The Via Numicia led to Brindis 
 (Brundusium) ; the Via Flatiinia 
 to Rimini and Aquileia ; the Via 
 Aurelia was along the coast of 
 Etruria ; the Via Cassia ran to Mo- 
 dena, between the Flaminian and 
 Aurelian ways ; the Via ^Emilia 
 extended from Rimini to Piacenza. 
 
 The smaller ways were, the Via 
 Pra3nestina to Palestrina (the an- 
 cient Prseneste) ; Tiburtina to Ti- 
 voli ; Ostiensis to Ostia ; Lauren- 
 tina to Laurentum, south of Ostia; 
 Salaria, etc. The cross-roads were 
 called Diverticula. 
 
 Italian architecture comprises so 
 many diversities that it is hardly 
 
 253 
 
 possible to affix to it anything like 
 a precise character, except by limit- 
 ing it to a particular epoch or 
 school, or to one special class of 
 buildings; and even then the ex- 
 ceptions may be more numerous 
 than the examples referred to as a 
 standard. With many vices and 
 defects, it possesses many excel- 
 lences and recommendations, and a 
 variety of resources, which render 
 it capable of being turned to far 
 greater account than hitherto has 
 been done. But if on the one 
 hand it affords much scope to the 
 architect, it calls on the other for 
 the exercise of discriminating taste, 
 one that not only rejects what is 
 positively bad, but is capable of 
 re-combining all the better ele- 
 ments of the style, so as to impart 
 to them originality and freshness, 
 without forfeiting what is valuable 
 in and characteristic of the style 
 itself, so that, instead of appearing 
 contrary to its genius, the novel 
 forms and effects that may be pro- j 
 duced shall seem to be beauties, 
 which have merely been lying la- 
 tent, and waiting for a discoverer 
 to bring them to light. A style is 
 to be judged of, not only retro- 
 spectively by what it has produced, 
 but prospectively also, according to 
 what it is capable of supplying. 
 Nevertheless, so far from being at 
 all encouraged, such view of the 
 subject is kept out of sight as much 
 as possible ; and precedent is al- 
 lowed to usurp such sway, that any 
 departure from it, no matter in 
 what spirit, is liable to be con- 
 founded with and reprobated as 
 capricious innovation, although the 
 one proceeds quite in an opposite 
 direction to the other. 
 Italian church (the), in the front or 
 facade, is never true to the internal 
 structure ; it is always divided into 
 two apparent stories, by two heights 
 of pillars, or pilasters, and by win- 
 dows, or alcoves ; but the greater 
 number of churches in Rome have 
 the outward look of large dwelling- 
 
ITA 
 
 IVORY. 
 
 JET 
 
 houses, a highly ornamented centus, 
 and wings less so, with two or three 
 ranges of windows, not differing 
 from a habitable house. 
 
 Italian varnish, for painting, is pre- 
 pared by incorporating over a slow 
 fire two parts of linseed or nut oil 
 with one part of litharge, ground 
 fine. The mixture must be fre- 
 quently stirred to quicken the 
 operation. 
 
 Ivory is first mentioned in the reign 
 of Solomon : ivory was used in de- 
 corating those boxes of perfumes 
 whose odours were employed to 
 exhilarate tne King's spirits. It is 
 probable that Solomon, who traded 
 
 in India, first brought thence ele- 
 phants and ivory into Judaea. Ca- 
 binets and wardrobes were orna- 
 mented with ivory by marquetry- 
 work. These were called ' houses 
 of ivory.' " Eighty more chests 
 of ivory, for your use and plea- 
 sure," are enumerated in the letter 
 which accompanied the very re- 
 markable tribute of the Ethiopian 
 queen, Candace, to Alexander the 
 Great. 
 
 Ivory-black and bone-black, ivory and 
 bone charred to blackness by strong 
 heat in closed vessels ; if skilfully 
 prepared, they are eligible for oil 
 and water painting. 
 
 J. 
 
 JACK, an instrument for raising a 
 heavy weight through a short dis- 
 tance ; it consists of a strong piece 
 of wood, with an iron rack which is 
 moved, by wheels fixed inside the 
 wood, from a handle outside. 
 
 Jack, in navigation, a flag or colour ; 
 a small union flag. 
 
 Jak-wood, a native of India, is im- 
 ported in logs from 3 ft. to 5 ft. 
 diameter ; the grain is coarse and 
 crooked : used in cabinet-work, 
 marquetry, and turning, and also 
 for brush-backs. 
 
 Jamb, in building, a supporter on 
 either side, as the posts of a door. 
 
 Jambs, the side pieces of any open- 
 ing in a wall, which bear the piece 
 that discharges the superincumbent 
 weight of such wall. 
 
 Janta, a machine extensively used 
 in Bengal and other parts of India, 
 to raise water for the irrigation of 
 land. It consists of a hollow 
 trough of wood, about 15 ft. long, 
 6 inches wide, and 10 inches deep, 
 and is placed on a horizontal beam 
 lying on bamboos fixed in the bank 
 of a pond or river : one end of the 
 trough rests upon the bank, where 
 a gutter is prepared to carry off the 
 water, and the other end is dipped 
 in the water by a man standing on 
 
 254 
 
 a stage, plunging it in with his 
 foot. 
 
 Janua, among the Romans, the street- 
 door of a private house. 
 
 Japanning, the art of painting and 
 varnishing on wood, leather, metal, 
 or paper, after the manner of the 
 Japanese. 
 
 Jasper is found along the shores of 
 the Bay of Chaleur, and other lo- 
 calities in the northern part of New 
 Brunswick. 
 
 Jaune mineral. This pigment is a 
 chromate of lead, prepared in Pa- 
 ris. The chrome-yellows have ob- 
 tained other names from places or 
 persons from whence they have 
 been brought, or by whom they 
 have been prepared, such as Jaune 
 de Cologne, etc. 
 
 Jesse (the root of), a term applica- 
 ble to the genealogy of Christ, as 
 affording subjects for the painter, 
 sculptor, or embroiderer. 
 
 Jet d"eau, a French expression, sig- 
 nifying a fountain that throws up 
 water to some height in the air. 
 
 Jetty, a part of a building that pro- 
 jects beyond the rest, and over- 
 hangs the wall below, as the upper 
 stories of timber houses, bay-win- 
 dows, pent-houses, small turrets at 
 the corners, etc. 
 
JET 
 
 JOINERY. 
 
 KEE 
 
 Jetty, a projecting erection into the 
 sea, partaking something of a pier, 
 mostly constructed of timber, with 
 open spaces for the sea to play. 
 
 Jewry, a district, street, or place or 
 locality, in which Jews formerly 
 resided. 
 
 Jib, the overhanging part of a crane, 
 or a triangular frame with a pulley 
 at the end, for the chain to pass 
 over which leads from the crane. 
 
 Jib, in navigation, the foremost sail 
 of a ship. 
 
 Jib-boom, a spar run out from the 
 bowsprit. 
 
 Jigger, a machine consisting of a 
 piece of rope about 5 feet long, 
 with a block at one end and a sheaf 
 at the other, used to hold on the ca- 
 ble when it is heaved into the ship 
 by the revolution of the windlass. 
 
 Jigging, in Cornwall, a method of 
 dressing the smaller copper and 
 lead ores, by the motion of a wire 
 sieve in a kieve or vat of water. 
 
 Joggle, a term in masonry, the art of 
 joining and fitting the stones to- 
 gether. 
 
 Joinery, the art of joining, compre- 
 hends all the fixed woodwork in- 
 tended for ornament or conveni- 
 ence in the interior of a house. 
 
 Joint, the interstices between the 
 stones or bricks in masonry and 
 brickwork are so called. 
 
 Joints, in carpentry, the secondary 
 beams of a floor ; those pieces of 
 timber framed into girders and 
 
 KAGE, anciently applied to chantry 
 chapels enclosed with lattices or 
 screen work. 
 
 Kaolin, aluminous earth ; the porce- 
 lain earth of the Chinese. 
 
 Kazer, in Cornwall, a sieve. 
 
 Kedging, in navigation, a term used 
 when a vessel is brought up or 
 down a narrow river or over a bar. 
 
 Keel (False), in ship-building, a strong 
 thick piece of timber bolted to the 
 bottom of the real keel, which is 
 very useful in preserving it. 
 
 summers, on which the boards of 
 the floor are laid. 
 
 Journal, a bearing of a shaft when it 
 is between the points where the 
 powers and resistance are applied ; 
 a bearing subject to torsion. 
 
 Jube, anciently, the rood-loft or gal- 
 lery over the entrance into the 
 choir of a cathedral or church. 
 
 Jugumentum, the lintel of a door. 
 
 Jumper, a long borer used by one 
 person. 
 
 Juniper wood, an aromatic and very 
 durable kind of wood. 
 
 Junk, an Indian or Chinese ship. 
 
 Junk-ring, a ring fitting a groove 
 round a piston, to make it steam- 
 tight. The ring is turned accu- 
 rately to the diameter of the cylin- 
 der, and slightly hammered all 
 round on the inside to increase its 
 elasticity; it is then cut open, and 
 put in its place : springs are some- 
 times used for pressing it outward. 
 
 Justice (Courts of). These places, 
 according to Palladio, were an- 
 ciently called Basilicae, where the 
 judges attended to administer jus- 
 tice, and where, sometimes, great 
 and important affairs were trans- 
 acted : whence we read, that the 
 tribunes of the people caused to be 
 taken away a column that inter- 
 rupted their benches, from the Ba- 
 silica Portia ; which was at Rome 
 near the temple of Romulus and 
 Remus, and is now the church of 
 St. Cosmus and Damianus. 
 
 Keels, in navigation, small vessels that 
 carry coals down the river Tyne. 
 
 Keelson, in ship-building, the piece 
 of timber attached to a ship's keel. 
 
 Keep, the chief tower or dungeon of 
 a Norman castle. 
 
 Keeping, in painting, is the observance 
 of a due proportion in the general 
 light and colouring of a picture, so 
 that no part be too vivid or more 
 glaring than another, but a proper 
 harmony and gradation be evident 
 in the whole performance. 
 
KEP 
 
 KEY-STONE. 
 
 KNI 
 
 Kept down is a term implying gloomi- 
 ness of tint, or an object so shaded 
 with fuscous colour that its form 
 can scarcely be determined ; which 
 object is not intended to be seen 
 by the spectator until he has re- 
 gularly observed all the other parts 
 of the painting, but which is ne- 
 cessary to the composition. 
 
 Kermes lake, an ancient pigment, per- 
 haps the earliest of the European 
 lakes : the name is probably derived 
 from the Alkermes of the Arabians, 
 from Kerraan, the ancient Carma- 
 nia, on the borders of Persia. 
 
 Kerned, a term applied to a heap of 
 mundic or copper ore hardened by 
 lying exposed to the sun. 
 
 Ketch, in navigation, a vessel with 
 masts and sails. 
 
 Revels, in ship-building, answer the 
 purpose of timber-heads, and are 
 sometimes fixed to the spirketing 
 on the quarter-deck, when the tim- 
 ber-heads are deficient. 
 
 Key, a term applied to a painting 
 when one object, generally the prin- 
 cipal one, is so worked up to its 
 proper tone, strength of colour, 
 etc., that the painter is compelled 
 to finish the whole piece in a mas- 
 terly manner : this is said to have 
 been the practice of Titian. 
 
 Key-grooving machine, a machine for 
 cutting the grooves or key-ways in 
 the boss of a wheel to be fixed on 
 a shaft. 
 
 Key-screw, a lever used for turning 
 screws. 
 
 Key-stone, the stone in an arch which 
 is equally distant from its springing 
 extremities. In a circular arch 
 there will be two key-stones, one 
 at the summit and the other at the 
 bottom thereof: in semi-circular, 
 semi-elliptical arches, etc., it is the 
 highest stone, frequently sculp- 
 tured on the face and return sides. 
 
 Kiabooca-wood, or Amboyna-ivood, 
 imported from Singapore, is very 
 ornamental, and is used for small 
 boxes and writing-desks. 
 
 Kibbal, a bucket in which ore is raised 
 from the mines. 
 
 256 
 
 Kieve, a vat or large iron-bound tub 
 for washing of ores. 
 
 Kilkenny marble, a fine black marble, 
 full of shells and corolloid bodies. 
 
 Killas, a clay slate occurring in dif- 
 ferent parts of a mine. 
 
 Killepe, anciently a gutter, groove, or 
 channel. 
 
 Kiln, a furnace for burning bricks and 
 tiles, also limestone or chalk, to 
 make lime; a place for drying malt 
 or hops. 
 
 Kilogramme (pronounced Kilo), a 
 French weight, equivalent to 2 Ibs. 
 3 oz. 5drs. 13 grs. avoirdupois. 
 
 King-at-arms, in heraldry, a principal 
 officer at arms. There are three : 
 Garter, Norroy, and Clarencieux. 
 
 King-post, the middle post of a rocf, 
 standing in the tie-beam and reach- 
 ing up to the ridge ; it is often 
 formed into an octagonal column 
 with capital and base, and small 
 struts or bases, which are slightly 
 curved, spreading from it above the 
 capital to some other timbers. 
 
 Kingston's valve, a flat valve forming 
 the outlet of the blow-off pipe of a 
 marine engine : it opens from the 
 side of the vessel by turning a screw. 
 
 King-wood, called also violet-wood, is 
 imported from the Brazils : it has 
 violet-streaked tints, and is used in 
 turnery and small cabinet-work. 
 
 Kirk, church, a term still used in 
 Scotland, formerly so in England. 
 
 Klinometer, or Clinometer, an instru- 
 ment contrived to measure the in- 
 clinations of stratified rocks, the 
 declivity of mountains, and the dip 
 of mineral strata. 
 
 Knee, a term sometimes used for the 
 return of the drip-stone at the 
 spring of an arch. 
 
 Kneller (Sir Godfrey), flourished dur- 
 ing Charles II.'s reign. 
 
 Knees, in ship - building, are the 
 crooked pieces of oak timber, or 
 iron, which secure the beams to 
 the side of the ship. 
 
 Knight-heads or bollard-timbers, the 
 timbers on each side nearest the 
 stem, and continued high enough 
 to secure the bowsprit. 
 
KNI 
 
 KYANIZING. 
 
 KYA 
 
 K/tits, small particles of lead ore. 
 
 Knoekings, lead ore with spar, as cut 
 from the veins. 
 
 Knot or Knob, a boss ; a round bunch 
 of leaves or flowers, or other orna- 
 ment of a similar kind. 
 
 Knuckle-timber, the foremost top 
 timber in the ship that forms the 
 buck-head ; the timbers abaft it, 
 as far as the angle is continued, 
 may be called knuckle-timbers. 
 
 Krems, Crems, or Kremnitz white, 
 a white carbonate of lead, named 
 from Crerns or Krems, in Austria; 
 also called Vienna white. 
 
 Kyanizing and Bumettizing. Kyani- 
 zing is a simple process by means 
 of which timber, canvas, and cord- 
 age, etc., may be preserved from 
 the effect of dry-rot, and seasoned 
 in a very short time. It was in- 
 vented by Mr. Kyan, who obtained 
 a patent for it, which was purchased 
 by a Company called the ' Anti- 
 Dry-rot Company,' constituted and 
 empowered by Act of Parliament. 
 The timber is prepared as fol- 
 lows : a wooden tank is put together 
 so that no metal of any kind can 
 come in contact with the solution 
 when the tank is charged. The 
 solution consists of corrosive subli- 
 mate and water, in the proportion 
 of 1 11). of corrosive sublimate to 
 10 gallons of water as a maximum 
 strength, and 1 Ib. to 15 gallons as 
 a minimum, according to the poro- 
 sity or absorption of the timber 
 subjected to the process. 
 
 Oak and fir timber absorb nearly 
 alike, but the domestic woods, such 
 as beech, poplar, elm, etc., are more 
 porous. 
 
 An hydrometer will mark accu- 
 rately the strength of the solution, 
 water being (vide diagram); then, 
 when the hydrometer sinks to 6, 
 it denotes that the solution con- 
 tains 1 Ib. of sublimate to 15 gallons 
 of water ; when it rises to 1 7, 1 Ib. 
 of sublimate to 5 gallons. 
 
 As a general rule, when it stands 
 midway between 5 and 10, the 
 solution will be the proper strength. 
 
 The corrosive sublimate will dis- 
 solve best in tepid water. 
 
 Water. 
 
 ~f 1 Ib. of cor. sub. to 
 15 gal. of water. 
 
 j- 1 Ib. to 10 gal. do. 
 
 15 
 
 1 Ib. to 5 gal. do. 
 
 The period required for satu- 
 rating timber depends on its thick- 
 ness : 24 hours are required for 
 each inch in thickness, for boards 
 and small timbers. 
 
 The timbers, after saturation, 
 should be placed under a shed or 
 cover from the sun and rain, to dry 
 gradually. 
 
 In about 14 days, deals and tim- 
 ber not exceeding 3 inches in thick- 
 ness will be perfectly dry and sea- 
 soned, and fit for use. Large timbers 
 will require a proportionate time, 
 according to their thickness. 
 
 The solution may be used ad 
 infinitum, as its strength is not 
 diminished ; but it will be advisable 
 to ascertain occasionally by the 
 hydrometer that it contains the re- 
 quired proportions of corrosive sub- 
 limate and water. 
 
 Professor Faraday and the late 
 Dr. Birkbeck have, with many 
 other scientific men, testified in the 
 strongest manner to the efficacy of 
 this solution. The former says, 
 with respect to the penetration of 
 the solution by steeping, without 
 
 257 
 
KYA 
 
 KYANIZING AND BURNETTIZING. 
 
 KYA 
 
 pressure, that it may be tested by 
 the application of a drop of hydro- 
 sulphuret of ammonia, which will 
 turn black on meeting with the 
 mercury. 
 
 In the cube of elm, the corrosive 
 sublimate may be traced by the 
 above test to the depth of from 
 to of an inch ; by the test of 
 voltaic action, from | to 1 inch. 
 
 In the cube of oak, with the same 
 test, it was found at i of an inch, 
 but irregular, and apparently fol- 
 lowing the fissures of the wood ; by 
 voltaic action, not quite so far as 
 in the elm. 
 
 In the cube of fir, the penetra- 
 tion was the least by the common 
 test, ^ to ^ of an inch : by voltaic 
 action, of an inch, the turpentine 
 in the wood probably being the 
 obstruction to penetration. 
 
 From this testimony it is evident 
 that when pressure is not used, the 
 timber should be worked up into 
 the form required before immer- 
 sion. 
 
 The patentees or Company, who 
 have also the means of saturating 
 with hydraulic pressure at their 
 establishment, similar to that at 
 Portsmouth Dockyard, under Sir 
 William Burnett's process, grant 
 licenses at the rate of 5*. per cubic 
 foot, internal dimensions of the 
 tank, and sell corrosive sublimate 
 at 4*. per Ib. 
 
 IJlb. is sufficient to saturate a 
 load of timber of 50 cubic feet, at 
 the rate of 1 Ib. of sublimate to 15 
 gallons of water. 
 
 The process has been for several 
 years extensively used for sleepers 
 on railroads. 
 
 Several of the sleepers on the 
 South-western Railway, which had 
 been subjected to this process, were 
 taken up, owing to their being 
 decayed, particularly in the chalk 
 districts. It was, however, stated 
 by the engineer that they had 
 been steeped at the Company's 
 works in a hasty manner, and that 
 he did not consider it conclusive 
 
 against the process ; that he had 
 never seen any wood decayed that 
 had been steeped by the patentees. 
 It is also said that neither Kyan's, 
 Burnett's, nor Payne's process, can 
 resist the combined effects of mois- 
 ture and great heat, say 80 Fahr. 
 
 BURNETTIZING. 
 
 Burnettizing is the process by 
 means of which timber, felt, can- 
 vas, cordage, cottons, and woollens, 
 may be preserved from dry-rot, 
 mildew, moth, and premature de- 
 cay. It takes its name from its 
 inventor, Sir William Burnett, 
 M.D., K.C.B.,F.R.S., of the Navy, 
 who took out a patent for it in 
 1837. 
 
 It consists in immersing the va- 
 rious substances above enumerated 
 in a solution of chloride of zinc 
 and water in a wooden tank, in the 
 proportion of 1 Ib. of chloride of 
 zinc to 4 gallons of water for wood, 
 and 1 Ib. of the chloride to 5 gal- 
 lons of water for the remainder of 
 the articles, with the exception of 
 felt, which requires 1 Ib. of the 
 chloride to 2 gallons of water. 
 
 Three-inch deals require to re- 
 main in the tank or cistern six 
 days, and all other woods in the 
 same proportion, or two days per 
 inch. They are then taken out and 
 put under a shed, on their ends, to 
 dry, and require for this purpose 
 from fourteen days to three months, 
 according to the thickness of the 
 wood, when they are fit for use. 
 
 The timber should be reduced to 
 the scantling required for use before 
 it is subjected to this process. 
 
 Canvas, yarn for cordage, cottons, 
 and woollens, require to be sus- 
 pended in the solution for forty- 
 eight hours. 
 
 The process, however, with re- 
 spect to timber, is much more ex- 
 peditiously and effectively done by 
 hydraulic pressure in her Majesty's 
 dockyard at Portsmouth, where 
 large quantities of timber, etc., are 
 prepared for the use of the Royal 
 Navy at the various dockyards in 
 
 258 
 
KYA 
 
 KYANIZING AND BURNETTIZING. 
 
 KYA 
 
 England, particularly for ships' 
 magazines. 
 
 There is a large wrought-iron 
 tank, 52 feet in length and 6 feet 
 in diameter, with a door 2 feet 6 
 inches x 2 feet at each end for 
 loading. 
 
 Timber of all sizes and descrip- 
 tions is put into this cylinder, which 
 contains ahout twenty loads. As 
 soon as it is filled, and the doors 
 well secured both against external 
 arid internal pressure, the air is ex- 
 hausted in the cylinder, and also in 
 the timber, by means of an air- 
 pump worked by a small rotatory 
 engine of 10-horse power, on the 
 Earl of Dundonald's principle, un- 
 til the barometer stands at 27: 
 the valve leading to the air-pump 
 is then shut, and the cock of a pipe 
 leading from the tank, filled with 
 the solution, to the cylinder, is 
 turned : the solution rushes into 
 the cylinder to fill up the partial 
 vacuum, and about half-fills it, 
 when the cock is turned, and the 
 air-pump again set to work until 
 the barometer stands at 27 3, when 
 the same process is repeated, and 
 the cylinder nearly filled with the 
 solution. 
 
 A pressure of 150 Ibs. per square 
 inch is then obtained by means of 
 a Bramah forcing-pump, connected 
 with an iron copper or reservoir, 
 filled with the solution, and com- 
 municating with the cylinder by 
 means of a pipe. This is worked 
 by hand until a valve placed on the 
 top of the cylinder, and loaded to 
 the required gauge, begins to lift. 
 
 The timber is then left in the 
 cylinder, subject to this pressure, 
 for eight hours, which is considered 
 sufficient for the largest logs, even 
 in a rough state. The solution 
 being then drawn off into the tank, 
 and the timber taken out of the 
 cylinder, it is re-loaded, and the 
 process repeated : the same solu- 
 tion is used for two months, when 
 fresh is prepared. 
 
 The same process for drying the 
 
 259 
 
 timber thus saturated is adopted, 
 as before stated. Canvas, felt, and 
 yarn, etc., are not subjected to 
 pressure. 
 
 The felt is used as a lining to the 
 magazines of men-of-war, between 
 two thicknesses of wood ; also to 
 cover over the steam-boilers of 
 steam-ships: it is said to be ren- 
 dered much less liable to combus- 
 tion by the process. 
 
 It is stated that in tropical cli- 
 mates, more especially in Africa, 
 the saturated canvas has stood the 
 climate, when the unprepared, un- 
 der similar circumstances, has ra- 
 pidly decayed. 
 
 Both Burnettizing and Kyani- 
 zing offer great advantages to the 
 engineer : 
 
 1 st. Wood of every kind is ren- 
 dered more durable, and is rapidly 
 seasoned. 
 
 2ndly. It brings into general 
 use larch, poplar, and a variety of 
 other indigenous woods, as well as 
 American pine, etc., which, with- 
 out the process, from being liable 
 to rapid decay, and being much 
 inferior to Baltic timber, are sel- 
 dom used in public buildings. 
 
 To the military engineer, these 
 inventions offer still greater advan- 
 tages. He is frequently called on, 
 in distant colonies, to construct 
 block-houses, stockades, bridges, 
 and barracks, where the only ma- 
 terial to be had in abundance is 
 the tree standing in the forest : to 
 him a few pounds of either ingre- 
 dient would be invaluable, by en- 
 abling him to season and render 
 durable the timber a few days after 
 it was cut down, and thus provide 
 him with the ready means of ren- 
 dering a distant post tenable in a 
 short time by a small body of men, 
 with the additional satisfaction of 
 knowing that the work thus hastily 
 erected would be found to be of a 
 permanent nature. 
 
 Kyste, a chest or coffin for the burial 
 of the dead. 
 
LAB 
 
 LAKE. 
 
 LAN 
 
 L. 
 
 LABURNUM, a small dark-greenish 
 broom-wood, is sometimes used in 
 ornamental cabinet-work. 
 
 Labyrinth, a series of hedges, mounds, 
 or walls, with numerous winding 
 passages ; intricate and winding 
 walks in a garden. 
 
 Lacing, a piece of compass or knee- 
 timber, fayed to the back of the 
 figure and the knee of the head 
 of a ship, and bolted to each. 
 
 Lacker, or Lacquer, a varnish applied 
 upon tin, brass, and other metals, to 
 preserve them from tarnishing, and 
 to improve their colour. 
 
 Lac lake is prepared from lac, an 
 Indian drug. It resembles cochi- 
 neal and kermes, being the produc- 
 tion of a species of insect. Its co- 
 lour is rich, transparent, and deep, 
 less brilliant and more durable 
 than those of cochineal and kermes, 
 but inferior in both these respects 
 to the colour of madder. 
 
 Laconicum, among the ancients, the 
 semicircular end of a bath ; a cir- 
 cular stove, for the purpose of 
 heating the sudatories, or sweating- 
 rooms of a bath : the use of the 
 dry bath is said to have been pre- 
 valent among the Lacedaemonians. 
 
 Lacunar, an arched roof or ceiling, 
 more especially the planking or 
 flooring above the porticoes. 
 
 Lacunaria, the ceiling of the ambu- 
 latory around the cella of a temple 
 or of the portico. The beams, 
 which extended from the wails to 
 the entablature, were intersected 
 by others ranged longitudinally : 
 the square spaces made by these 
 intersecting beams were contracted 
 towards the top, and were some- 
 times closed with single stones, 
 which might occasionally be re- 
 moved. 
 
 Lacunars, in architecture, are panels 
 or coffers in the ceilings of apart- 
 ments, and sometimes in the sof- 
 fits of the corona of the Ionic, 
 Corinthian, and Composite orders. 
 
 260 
 
 Lade, a passage of water, the mouth 
 of a river. 
 
 Lady-chapel, a chapel dedicated to 
 the blessed Virgin, 
 
 Laines, courses laid in the building 
 of walls. 
 
 Lake (colour), a name derived from 
 the lac or lacca of India, is the 
 cognomen of a variety of transpa- 
 rent red and other pigments of 
 great beauty, prepared for the most 
 part by precipitating coloured tinc- 
 tures of dyeing drugs upon alumine 
 and other earths, etc. The lakes 
 are hence a numerous class of pig- 
 ments, both with respect to the 
 variety of their appellations and 
 the substances from which they 
 are prepared. The colouring mat- 
 ter of common lake is Brazil wood, 
 which affords a very fugitive co- 
 lour. Superior red lakes are pre- 
 pared from cochineal, lac, and 
 kermes ; but the best of all are 
 those prepared from the root of 
 the rubia tinctoria, or madder- 
 plant. See Lac lake. 
 
 Lama, in mining, slime or schelm. 
 
 Lamina, the extremely thin plates or 
 layers of metal which compose the 
 solid metal. 
 
 Laminable, a term applied to metal 
 which may be extended by pass- 
 ing it between steel or hardened 
 (chilled) cast-iron rollers. 
 
 Laminated, disposed in layers or 
 plates. When metal can be readily 
 extended in all directions, under 
 the hammer, it is said to be mal- 
 leable, and when in fillets under 
 the rolling-press, it is said to be 
 laminable. 
 
 Lamp-black, a soot of resinous woods 
 obtained in the manufacturing of 
 tar and turpentine. It is a pure 
 carbonaceous substance of a fine 
 texture, intensely black and per- 
 fectly durable, which works well, 
 but dries badly in oil. 
 
 Lance wood, imported in long poles 
 from 3 to 6 inches in diameter, 
 
LAN 
 
 LANDSCAPE GARDENING. 
 
 LAN 
 
 from Cuba and Jamaica, is of a 
 paler yellow than box-wood : it is 
 selected for elastic works, as gig 
 shafts, archery bows and springs, 
 surveyors' rods, billiard cues, etc. 
 
 Landscape. In landscape we find Na- 
 ture employing broken colours in 
 enharmonic consonance and variety, 
 and equally true to picturesque re- 
 lations : she employs also broken 
 forms and figures in conjoint har- 
 mony with colours, occasionally 
 throwing into the composition a j 
 regular form or a primary. 
 
 Landscape Gardening. The outline i 
 of a wood may sometimes be great, I 
 and always beautiful, but the first 
 requisite is irregularity. That a 
 mixture of trees and underwood j 
 should form a long straight line, I 
 can never be natural ; and a sue- j 
 cession of easy sweeps and gentle j 
 rounds, each a portion of a greater I 
 or less circle, composing altogether j 
 a line literally serpentine, is, if pos- j 
 sible, worse ; it is but a number of I 
 regularities put together in a disor- 
 derly manner, and equally distant 
 from the beautiful, both of art and 
 of nature. 
 
 The true beauty of an outline 
 consists more in breaks than in 
 sweeps ; rather in angles than 
 rounds ; in variety, not in succes- 
 sion. The outline of a wood is a 
 continued line, and small variations 
 do not save it from the insipidity 
 of sameness : one deep recess, one 
 bold prominence, has more effect 
 than twenty little irregularities ; 
 and that one divides the line into 
 parts, but no breach is thereby 
 made in its unity : a continuation 
 of wood always remains, the form 
 of it only is altered, and the extent 
 increased : the eye, which hurries 
 to the extremity of whatever is 
 uniform, delights to trace a varied 
 line through all its intricacies, to 
 pause from stage to stage, and so 
 lengthen the progress. 
 
 The parts must not, however, on 
 that account, be multiplied till they 
 are too minute to be interesting, 
 
 261 
 
 and so numerous as to create con- 
 fusion : a few large parts should 
 be more strongly distinguished in 
 their forms, their directions, and 
 their situations : each of these may 
 afterwards be decorated with sub- 
 ordinate varieties, and the mere 
 growth of the plants will occasion 
 some irregularity : on many occa- 
 sions more will not be required. 
 Every variety in the outline of a 
 wood must be a prominence or a 
 recess ; breadth in either is not so 
 important as length to the one and 
 depth to the other : if the former 
 ends in an angle, or the latter di- 
 minishes to a point, they have more 
 force than a shallow dust or a 
 dwarf excrescence, how wide so- 
 ever : they are greater deviations 
 from the continued line which they 
 are intended to break, and their 
 effect is to enlarge the wood itself. 
 
 Every variety of outline hitherto 
 mentioned may be traced by the 
 underwood alone ; but frequently 
 the same effects may be produced 
 with more ease, and much more 
 beauty, by a few trees standing out 
 from the thicket, and belonging or 
 seeming to belong to the wood, so 
 as to make a part of its figure. 
 
 The materials of natural land- 
 scape are ground, wood, and water, 
 to which man adds buildings, and 
 adapts them to the scene : it is 
 therefore from the artificial con- 
 siderations of utility, convenience, 
 and propriety, that a place derives 
 its real value in the eyes of a man 
 of taste : he will discover graces 
 and defects in every situation ; he 
 will be as much delighted with a 
 bed of flowers as with a forest 
 thicket, and he will be as much 
 disgusted by the fanciful affecta- 
 tion of rude nature in tame scenery 
 as by the trimness of spruce art in 
 that which is wild. 
 Landscape Painting. The best paint- 
 ers in landscape have studied in 
 Italy or France, where the verdure 
 of England is unknown : hence 
 arises the habit acquired by the 
 
LAN 
 
 LATHE. 
 
 LAT 
 
 connoisseur, of admiring the brown 
 tints and arid foregrounds in the 
 pictures of Claude and Poussin ; 
 and from this cause he prefers the 
 bistre sketches to the green paint- 
 ings of Gainsborough. One of our 
 best landscape painters studied in 
 Ireland, where the soil is not so 
 yellow as in England ; and his pic- 
 tures, however beautiful in design 
 and composition, are always cold 
 and chalky. Autumn is the fa- 
 vourite season of study for land- 
 scape painters, when all nature 
 verges towards decay, when the 
 foliage changes its vivid green to 
 brown and orange, and the lawns 
 put on their russet hue : but the 
 tints and verdant colouring of 
 spring and summer will have su- 
 perior charms to those who de- 
 light in the perfection of nature, 
 without perhaps ever considering 
 whether they are adapted to the 
 painter's landscape. 
 
 Land Steward. A person solely occu- 
 pied in the management and culti- 
 vation of an estate should see to 
 the production, advancement, and 
 value of the land ; should be well 
 acquainted with the pursuits and 
 interests of country life ; should un- 
 derstand the qualities of the soil 
 and the proper manuring of the 
 same, as well as the different com- 
 binations of sand, gravel, loam, 
 clay, chalk; he should be able to 
 show what stock the pasture will 
 maintain, what quantity of grain 
 the arable land will produce, and 
 what quantity of hay may be ex- 
 pected from the meadows : with 
 other requisite knowledge pertain- 
 ing to farming, he will be able to 
 form a fair estimate of the produce 
 of the farm, to keep accounts, and 
 ultimately acquire a taste for the 
 erection of farm buildings and la- 
 bourers' rural cottages, and also the 
 arrangement of landscape, flower, 
 and vegetable gardens. 
 
 Laniard, in navigation, a stout piece 
 of line or cord used to fasten and 
 secure the shrouds, stays, or buoys. 
 
 262 
 
 Lantern, in architecture, a small 
 structure on the top of a dome or 
 in similar situations for the admis- 
 sion of light, and the promotion of 
 ventilation. It is generally made 
 ornamental, and was much used in 
 Gothic and Tudor architecture. 
 
 Lanzi (Abbate Luigi), the author of 
 the ' History of Painting in Italy,' 
 was born in 1732 and died in 1810. 
 
 Lapidarius, a lapidary, a stone-cutter. 
 
 Lapis lazuli, a mineral which fur- 
 nishes the valuable pigment called 
 ultramarine. 
 
 Lapis lydius, a variety of touchstone ; 
 the schistose jasper of Brongniart, 
 containing silica, iron, alumina, 
 and charcoal. 
 
 Laque minerale is a French pigment, 
 a species of chromic orange. This 
 name is also given to orange oxide 
 of iron. 
 
 Larboard, in navigation, the left-hand 
 side of a ship, standing with face to 
 the head : now the word ' Port ' is 
 used. 
 
 Larch, a tree, larchwood, much grown 
 by the I Juke of Athol, in Scotland. 
 There are three species, one Euro- 
 pean and two American. 
 
 Lardrose, a screen at the back of a 
 seat behind an altar. 
 
 Later, a brick or tile. Besides the 
 Greeks and Romans, other ancient 
 nations employed brick for build- 
 ing to a great extent, especially the 
 Babylonians and Egyptians. 
 
 Lathe, a machine for turning metals 
 or wood by causing the material to 
 revolve upon central points, and be 
 cut by a tool fixed in a slide-rest, 
 or held by hand. 
 
 The lathe is very ancient, and 
 seems to have been known to the 
 Greeks and Romans, but, till within 
 the last half century, was a very 
 rough and almost powerless ma- 
 chine compared with the elegant, 
 very powerful, and well constructed 
 machine now in use. It is used for 
 turning either metal or timber, and 
 varies in size and construction, ac- 
 cording to the nature of the work 
 required. 
 
LAYER. 
 
 LEA 
 
 The construction of the present 
 lathe is as follows : a long frame, 
 called the lathe-bed, having a per- 
 fectly planed surface, and a slot or 
 mortise from end to end, is fixed at 
 each end upon two short standards, 
 and .upon one end of it a frame, 
 called the head-stock or mandril- 
 frame, is bolted : this frame carries 
 the short shaft or mandril, upon 
 which are the driving pulleys. The 
 end of the mandril stands through 
 the inner side of the frame, and is 
 screwed so that a socket or centre 
 chuck may be fixed on it : this 
 chuck acts as a centre for the work 
 to rest upon, and has a projecting 
 arm or driver to carry it round with 
 it. Another frame, called the back 
 centre frame, capable of being fixed 
 upon the lathe-bed at any distance 
 from the front centre, has a cylin- 
 der, with a pointed end or centre, 
 at precisely the same height as the 
 other, with two set-screws, one to 
 adjust the centre piece, the other 
 to fix it. The work is placed be- 
 tween these two centres, and caused 
 to revolve by a band passing over 
 a pulley on the mandril, if the lathe 
 is large, and by a treddle and band- 
 wheel, if the lathe is small. 
 
 In small lathes, the rest, upon 
 which the tool is held, is fixed in 
 a socket cast on a small slide by a 
 set-screw : the slide is for adjust- 
 ing its position, and is capable of 
 being fixed at any part of the lathe- 
 bed between the centres. 
 
 In large lathes the slide-rest is 
 always used. See Slide-rest. 
 
 Lathe-bed, that part of a lathe on 
 which the c poppet-head ' slides 
 forward or backward to its required 
 position. 
 
 Latitude, breadth, width, extent ; in 
 geography, the distance, north or 
 south, from the equator, a great 
 circle, equally distant from the 
 poles, dividing the globe into equal 
 parts, north and south. 
 
 Latten, a mixed metal resembling 
 brass. The monumental brasses in 
 churches are called latten. 
 
 Lattern-sail, in navigation, a long 
 triangular sail used in xebecs, etc. 
 
 Launders, in mining, tubes and gut- 
 ters for the conveyance of water in 
 mines, etc. 
 
 Lavatory, a cistern or trough to wash 
 in, used formerly in monasteries. 
 
 Laver, brazen. Moses was directed 
 to make, among other articles of 
 furniture, for the services of the ta- 
 bernacle, a laver of brass, borne by 
 four cherubim, standing upon bases 
 or pedestals, mounted on brazen 
 wheels, and having handles belong- 
 ing to them, by means of which they 
 might be drawn and conveyed from 
 one place to another, as they should 
 be wanted. These lavers were 
 double, composed of a basin which 
 received the water that fell from 
 another square vessel above it, from 
 which the water was drawn by cocks. 
 The whole work was of brass : the 
 square vessel was adorned with the 
 heads of a lion, an ox, and a cherub. 
 Each of the lavers contained forty 
 baths, or four bushels, forty-one 
 pints, and forty cubic inches of 
 Paris measure. 
 
 Lay figure, a figure made of wood 
 or cork, in imitation of the human 
 body. It can be placed in any po- 
 sition or attitude, and moves at 
 every joint, on the principle of the 
 ball and socket. It serves, when 
 clothed, as a model for drapery 
 and for foreshortening. The dress 
 of the person is generally placed on 
 the lay-figure after the head is 
 taken, by which the painter finishes 
 his entire portrait at leisure, with- 
 out requiring the person to sit. 
 
 Lazaretto, an hospital ship for the 
 reception of the sick. 
 
 Lead is a very heavy metal, suffici- 
 ently well known. The mode of 
 purifying it from the dross which 
 is mixed with it, by subjecting it to 
 a fierce flame, and melting off its 
 scoria, furnishes several allusions 
 in Scripture to God's purifying or 
 punishing his people. It was one 
 of the substances used for writing 
 upon by the ancients. 
 
LEA 
 
 LEVELLING. 
 
 LEV 
 
 Lead spar, sulphate of lead. 
 
 Leader, a branch, rib, or string of ore, 
 leading along to the lode. 
 
 Leading springs, the springs fixed 
 upon the leading axle-box of a 
 locomotive engine, bearing the 
 weight above. 
 
 Leading wheels, the wheels of a loco- 
 motive engine, which are placed 
 before the driving wheels. 
 
 Lease, holding of land or house for a 
 term of years at a rent. 
 
 Leaf, a water-course, or level for con- 
 veyance of water. 
 
 Leaves, a term applied to window- 
 shutters, the folding-doors of clo- 
 sets, etc. 
 
 Leaving (in Cornish), or casualties, 
 in tin, is the same as hanaways of 
 copper or lead ore. 
 
 Lectern or Lettern, the desk or stand 
 on which the larger books used in 
 the services of the Roman Catholic 
 church are placed. In modern 
 Protestant churches they are now 
 often used, and are very ornamental 
 in appearance, and far more ap- 
 propriate than the cumbersome 
 reading-desk. Lecterns are made 
 sometimes of stone or marble, but 
 usually of wood and brass, and 
 generally are extremely well exe- 
 cuted. 
 
 Lectus, a bed or couch. 
 
 Ledger, a large flat stone laid over a 
 tomb : horizontal timbers used in 
 forming scaffolding are also called 
 ledgers. 
 
 Ledgment, a string-course, or hori- 
 zontal suite of mouldings, such as 
 the base-mouldings of a building. 
 
 Lee, in navigation, the side opposite | 
 to the wind; as the lee-shore is j 
 that on which the wind blows. 
 
 Lely (Sir Peter), flourished in Charles 
 ll.'s reign. 
 
 Lembus, according to Plautus, a skiff 
 or small boat, used for carrying a 
 person from a ship to the shore. 
 
 Lemon yellow, a beautiful light and 
 vivid colour. In body and opacity 
 it is nearly equal to Naples yellow 
 and tnasticot, but much more pure 
 and lucid in colour and tint, and at 
 
 264 
 
 the same time not liable to change 
 by damp, sulphurous or impure air, 
 or by the action of light, or by the 
 steel palette-knife, or by mixture 
 of white lead or other pigments, 
 either in water or oil. 
 Lessee, one to whom a lease is. given. 
 Lessor, one who grants a lease. 
 Levecel, anciently a pent-house, or a 
 projecting roof over a window, 
 door, etc. 
 
 Level, an instrument for determining 
 the heights of one place with re- 
 spect to another. 
 
 Levelling, the art by which the rela- 
 tive heights of any number of 
 points are determined. 
 
 The height of a point is the 
 vertical distance to which it is ele- 
 vated or depressed, as compared 
 with the true general surface of 
 the earth. 
 
 The earth is in form a spheroid. 
 On laud we can nowhere trace its 
 true geometric surface ; but the 
 sea, when at rest, presents every- 
 where a very near approximation 
 to it, and hence the level of the 
 sea has been assumed as the stan- 
 dard to which all heights are to be 
 referred. 
 
 The absolute height, then, of any 
 point is its vertical distance from 
 the level of the sea: the relative 
 height of two or more points, com- 
 monly called their difference of 
 level, is the difference of those 
 vertical distances. 
 
 A true level is any surface or 
 line which is parallel to the true 
 geometric surface of the earth ; 
 every true level must, therefore, 
 necessarily present a curve every- 
 where perpendicular to the direc- 
 tion of gravity. It is a beautiful 
 property of fluids that in every 
 situation, when at rest, their sur- 
 face will present a true level. 
 
 All points situated within the 
 same true level are evidently at the 
 same height. 
 
 One point is said to be higher or 
 lower than another, according as a 
 true level traced through it passes 
 
LEV 
 
 LIGHT. 
 
 LIG 
 
 above or below that point ; and 
 the vertical distance at which it so 
 passes is the measure of its relative 
 height. 
 
 In theory, levelling is extremely 
 simple. It consists in tracing 
 through space a series of level sur- 
 faces, and finding their intersec- 
 tions with vertical lines passing 
 through the points whose relative 
 height we wished to ascertain. 
 
 Level (Road), a triangular frame of 
 wood with a long straight base, and 
 a plummet suspended by a thread 
 from the vertex of the triangle. 
 When the ground to which it is 
 applied is level, the thread will co- 
 incide with a line perpendicular to 
 the base. 
 
 A tool similar in principle to the 
 above-mentioned is used by fitters, 
 and is made of a plate of sheet- 
 iron, two sides of which form a 
 right angle, and the thread which 
 suspends the plummet is parallel to 
 the vertical side when the base is 
 level. 
 
 Level (Spirit}, a glass tube, closed at 
 the ends, and nearly filled with 
 water or spirits, fixed in a piece of 
 wood or metal with a flat base, to 
 which the tube is perfectly parallel. 
 When placed upon a level surface, 
 an air-bubble will be at the centre 
 of the tube. 
 
 Lever, the first mechanical power, 
 being an inflexible straight bar, 
 supported in a single point on a 
 fulcrum or prop, called its centre 
 of motion : it is used to elevate a 
 great weight. 
 
 Lever-valve, a safety-valve kept in its 
 seat by the pressure of a lever with 
 an adjustable weight. In locomo- 
 tive engines a spring is used at the 
 end of the lever, instead of the 
 weight; and the pressure is regu- 
 lated by a screw, and indicated on 
 a brass plate. 
 
 Levigation, the process of reducing 
 hard bodies into subtile powder by 
 grinding upon marble with a muller. 
 
 Lewis, an instrument used by masons 
 for hoisting, consisting of thin 
 
 265 
 
 wedges of iron, forming a dovetail, 
 which is indented into a large stone 
 for the purpose of moving it. 
 
 Ley, a standard of metal ; contents in 
 pure metal. 
 
 Libella, a small balance ; a level used 
 by carpenters and masons to taet 
 flat surfaces. 
 
 Libra, a pound weight; a balance, or 
 a pair of scales : one of the twelve 
 signs of the zodiac. 
 
 Library, a room or rooms appropria- 
 ted for the arrangement and keep- 
 ing of books, fitted up with shelves 
 to hold them, or furniture called 
 book-cases, to which shelves are 
 affixed for the same purpose. 
 
 Lich-gate, a gate belonging to church- 
 yards. 
 
 Lifting-gear, the apparatus for lifting 
 the safety-valves from within a 
 boiler : it consists of levers con- 
 nected to the valve and to a screw- 
 worked by a handle outside the 
 boiler. 
 
 Lifts, in navigation, the ropes at the 
 yard-arms, used to make the yards 
 hang higher or lower, as required. 
 
 Light. The meteorological pheno- 
 mena induced by the action of light 
 are, chiefly, atmospheric refraction, 
 i, e. the temperature of the different 
 strata of the atmosphere ; the tints 
 which at certain times spread over 
 the disc of the sun, the moon, and 
 the stars; the various aspects of 
 the waters of the ocean, of seas, 
 and of lakes; the Fata Morgana, 
 the mirage, and all those varied 
 optical appearances which both 
 celestial and terrestrial objects pre- 
 sent when seen through atmosphe- 
 ric strata of different degrees of 
 elasticity. 
 
 Light red is an ochre of a russet- 
 orange hue ; principally valued for 
 its tints. The common light red 
 is brown ochre burnt ; but the prin- 
 cipal yellow ochres afford this 
 colour best ; and the brighter and 
 better the yellow from which this 
 pigment is prepared, the brighter 
 will this red be, and the better j 
 flesh tints will it afford with white. ! 
 
LIG 
 
 LIMESTONE. 
 
 LTM 
 
 Lignum vita, or Guaiacum, is a verji 
 hard and heavy wood, shipped from 
 Cuba and other adjacent islands. 
 When first cut, it is soft and easily 
 worked ; hut it speedily becomes 
 much harder on exposure to the 
 ir. It is cross-grained, covered 
 with a smooth yellow sap, like box, 
 almost as hard as the wood, which 
 is of a dull brownish-green, and 
 contains a large quantity of the 
 gum guaiacum, which is extracted 
 for the purposes of medicine. The 
 wood is used in machinery, and for 
 rollers, presses, mills, pestles and 
 mortars, sheaves for ships' blocks, 
 skittle-balls, etc. 
 
 Limber-boards, short pieces of plank 
 fitted from the limber-strake to the 
 keelson of a ship, butting at the 
 sides of all the bulk-heads, that 
 they may be easily taken up. 
 
 Limber-strake, the strake of wood 
 waleing nearest the keelson, from 
 the upper side of which the depth 
 in the hold of a vessel is measured. 
 
 Lime, or Quicklime. When required 
 perfectly pure, lime is obtained by 
 heating to whiteness, in an open 
 platinum crucible, precipitated car- 
 bonate: most marbles yield it mo- 
 derately pure ; but as prepared for 
 ordinary purposes, by the calcina- 
 tion of common limestone in a fur- 
 nace with eoal, it is far otherwise. 
 
 Limestone becomes lime on being de- 
 prived of its carbonic acid and of 
 the water it contains, whether hy- 
 grometrically or in combination. 
 The agent employed to effect this 
 is heat. 
 
 With the same heat, the calci- 
 nation is effected with more ease 
 and rapidity, in proportion as the 
 stone is of a less compact texture 
 than the stnallness in bulk of the 
 fragments into which it is reduced, 
 or to its being impregnated with 
 a certain degree of humidity. 
 
 The contact of the air is not in- 
 dispensable, but it exercises a useful 
 influence, especially in regard to 
 argillaceous limestone. Moreover, 
 no limestone can be converted into 
 
 266 
 
 lime in a vessel so close as to ren- 
 der the escape of the carbonic acid 
 impossible. 
 
 Limestone which is pure, or 
 nearly so, supports a white heat 
 without inconvenience. Under the 
 intense heat of the hydro-oxygen 
 blow-pipe,this substance affords the 
 brilliant light, the beautiful appli- 
 cation of which to the microscope 
 is now so well known. The com- 
 pound limestone, on the other hand, 
 alloyed in the proportions necessary 
 to form hydraulic or eminently 
 hydraulic lime, fuses easily. Its 
 calcination demands certain pre- 
 cautions : the heat ought never to 
 be pushed beyond the common red 
 heat, the intensity being made up 
 for by its duration. 
 
 The compound limestone, when 
 too much burnt, is heavy, compact, 
 dark-coloured, covered with a kind 
 of enamel, especially about the an- 
 gular parts ; it slakes with great 
 difficulty, and gives a lime carbon- 
 ized and without energy : some- 
 times it will not slake at all, but 
 becomes reduced, after some days' 
 exposure to the air, to a harsh 
 powder altogether inert. 
 
 The pure and compound lime- 
 stones, when insufficiently burnt, 
 either refuse to slake, or slake only 
 partially, leaving a solid kernel, a 
 kind of sub-carbonate with excess 
 of base. 
 
 The calcining of calcareous mi- 
 nerals constitutes the art of the 
 lime-burner. According to situa- 
 tion, either fire-wood, fagots, brush- 
 wood, turf, or coal is used. 
 
 Lime-kilns of various kinds have 
 been suggested and tried. The 
 forms of interior most generally 
 adopted are, 1st, the upright rect- 
 angular prism ; 2nd, the cylin- 
 der ; 3rd, the cylinder surmounted 
 by an erect cone slightly trun- 
 cated ; 4th, a truncated inverted 
 cone ; 5th, an ellipsoid of revolu- 
 tion variously curvated, or an egg- 
 shaped kiln. 
 
 The rectangular kilns are in use 
 
LIM 
 
 LIMESTONE. 
 
 LIM 
 
 in Nivernais, and in the south of 
 France, in which are burnt, at the 
 same time, limestone and bricks. 
 The limestone occupies very nearly 
 the lower half of the capacity. The 
 upper is filled with bricks, or tiles, 
 laid and packed edgewise. 
 
 The cylindric kilns are princi- 
 pally employed upon works which 
 consume a large quantity of lime in 
 a short time. They are termed 
 ' field-kilns ;' their construction is 
 expeditious and economical, but 
 precarious. Above a pointed oven- 
 shaped vault, is raised, in the form 
 of a tower, a high stack of lime- 
 stone, which is enclosed by a cur- 
 tain of rammed earth, and sup- 
 ported outwardly by a coarse wat- 
 tling, in which care is taken to 
 leave an opening to introduce the 
 fire beneath the vault. 
 
 The kilns of the third kind are 
 constructed in a solid and durable 
 manner, like the four-sided kilns : 
 no bricks are burnt in these ; the 
 largest stones occupy the lower 
 part of the cylinder ; the smaller 
 pieces and fragments are thrown 
 into the cone which surmounts it. 
 
 The kilns of the fourth and fifth 
 kind are specially intended for the 
 burning with coal. 
 
 The interior wall of the kiln is 
 generally built with bricks, or other 
 material unalterable by heat, ce- 
 mented throughout a thickness of 
 from 12 to 15 inches with a mix- 
 ture of sand and refractory clay, 
 beaten together. 
 
 In the flare-kilns fed by logs or 
 brushwood, the charge always rests 
 upon one or two vaults built up 
 dry with the materials of the charge 
 itself. Underneath these vaults 
 a small fire is lighted, which is 
 gradually increased as they retire, 
 in proportion as the draught esta- 
 blishes itself and gains force. On 
 reaching the exterior, the aperture 
 at the eye of the kiln is suitably 
 adjusted, and then kept constantly 
 filled with the combustible. The 
 air which rushes in carries the flame 
 
 267 
 
 to a distance over every point of the 
 vaults : it insinuates itself by the 
 joints, and is not long in extending 
 the incandescence by degrees to the 
 highest parts. 
 
 There are some kinds of stone 
 which the fire, however well re- 
 gulated, seizes suddenly, and causes 
 to fly with detonation : they can- 
 not, without the risk of spoiling 
 the charge, be used for the con- 
 struction of the vaults and piers in 
 loading the kiln. In such a case, 
 materials which are free from this 
 inconvenience are employed. 
 
 Practice can alone indicate the 
 time proper for the calcination. It 
 varies with a multitude of circum- 
 stances, such as the more or less 
 green, more or less dry quality of 
 the wood ; the direction of the 
 wind, if it favour the draught, or 
 otherwise, etc. The master-burners 
 usually judge by the general settling 
 of the charge, which varies from 
 to . In a kiln of the capacity 
 of from 211-8 to 264'75 cubic feet, 
 the five lasts from 100 to 150 
 hours. 
 
 In the coal-kilns by slow heat, 
 the stone and coal are mixed. Of 
 all the methods of burning lime, 
 this is certainly the most precarious 
 and difficult, more especially when 
 applied to the argillaceous lime- 
 stone. A mere change in the du- 
 ration or intensity of the wind, any 
 dilapidation of the interior wall of 
 the kiln, a too great inequality in 
 the size of the fragments, are so 
 many causes which may retard or 
 accelerate the draught, and occasion 
 irregular movements in the descent 
 of the materials, which become 
 locked together, form a vault, and 
 precipitate at one time the coal, and 
 another the stone, upon the same 
 point : hence an excess or deficiency 
 in the calcination. 
 
 Sometimes a kiln works perfectly 
 well for many weeks, and then all 
 at once gets out of order without 
 any visible cause. A mere change 
 in the quality of the coal is suf 
 
 2* 
 
LIM 
 
 LIME. 
 
 LIM 
 
 ficient to lead the most experience^ 
 lime-burner into error. In a word, 
 the calcination by means of coal, 
 and the slow heat, is an affair of 
 cautious investigation and practice. 
 
 The capacity of a furnace con- 
 tributes, no less than does its form, 
 to an equable and proper calcina- 
 tion. There are limits beyond 
 which they cannot be enlarged 
 without serious evils. 
 
 The bulk of coal burnt to pro- 
 duce a cubic foot of lime neces- 
 sarily varies with the hardness of [ 
 the limestone used, but within 
 narrow limits. 
 
 The calcination of limestones j 
 presents other important problems, j 
 which can only be solved by expe- 
 riment. 
 
 Limes, hydraulic (artificial). Already 
 the artificial limes have been ap- 
 plied to a number of important 
 works. In the canals of St. Martin 
 and St. Maur they have almost ex- 
 clusively been used, and nearly a 
 thousand cubic metres have been 
 employed within five years at the 
 harbour of Toulon. These limes 
 have served for the fabrication of 
 the mortar for the foundations of 
 several bridges, and their con- 
 sumption is increasing daily in 
 Paris and its environs. 
 
 The artificial hydraulic limes are 
 prepared by two methods ; the 
 most perfect, but also the most 
 expensive, consists in mixing with 
 rich lime, slaked in any way, a 
 certain proportion of clay, and cal- 
 cining the mixture: this is termed 
 ' artificial Ume twice kilned* 
 
 By the second process, any very 
 soft calcareous substance is sub- 
 stituted for the lime (such, for ex- 
 ample, as chalk, or the tufas), 
 which it is easy to bruise and re- 
 duce to a paste with water. From 
 this a great saving is derived, but 
 at the same time an artificial lime 
 perhaps of not quite so excellent a 
 quality as by the first process, in con- 
 sequence of the rather less perfect 
 amalgamation of the mixture. In 
 
 268 
 
 fact, it is impossible, by mere me- 
 chanical agency, to reduce calcare- 
 ous substances to the same degree 
 of fineness as slaked lime. Never- 
 theless, this second process is the 
 more generally followed, and the 
 results to which it leads become 
 more and more satisfactory. 
 
 By a proper regulation of the 
 proportions, a degree of energy 
 may be given to the factitious lime, 
 which will render it equal, if not 
 superior, to the natural hydraulic 
 limes. 
 
 It is usual to take twenty parts of 
 dry clay to eighty parts of very 
 rich lime, or to one hundred and 
 forty of carbonate of lime. But if 
 the lime or its carbonate should 
 already be at all mixed in the na- 
 tural state, then fifteen parts of 
 clay will be sufficient. Moreover, 
 it is proper to determine the pro- 
 portions for every locality. In 
 fact, all clays do not resemble one 
 another to such an extent as to 
 admit of their being considered as 
 identical: the finest and softest 
 are the best. 
 
 There is at Meudon, near Paris, 
 a manufactory of artificial lime, set 
 on foot by Messrs. Brian and St. 
 Leger. The materials made use of 
 are, the chalk of the country and 
 the clay of Vaugirard, which is 
 previously broken up into lumps of 
 a moderate size. A millstone set 
 up edgewise, and a strong wheel 
 with spokes and felloes, firmly at- 
 tached to a set of harrows and 
 rakes, are set in movement by a two- 
 horse gin, in a circular basin of 
 about six feet and a half radius. 
 In the middle of the basin is a 
 pillar of masonry, on which turns 
 the vertical arbor to which the 
 whole system is fixed : into this j 
 basin, to which water is conveyed 
 by means of a cock, four measures ! 
 of chalk are successively thrown, ! 
 and one measure of clay. After an j 
 hour and a half's working, about j 
 fifty-three cubic feet (English) of a 
 thin pulp is obtained, which is 
 
LINK-MOTION. 
 
 LIN 
 
 drawn off by means of a conduit, 
 pierced horizontally on a level with 
 the bottom of the basin. 
 
 The fluid descends by its own 
 weight; first into one excavation, 
 then into a second, then a third, 
 and so on to a fourth or fifth. 
 These excavations communicate 
 with one another at top. When 
 the first is full, the fresh liquid, as 
 it arrives, as well as the super- 
 natant fluids, flow over into the 
 second excavation ; from the second 
 into the third, and so on to the 
 last, the clear water from which 
 drains off into a cesspool. Other 
 excavations, cut in steps like the 
 preceding, serve to receive the 
 fresh products of the work, whilst 
 the material in the first series ac- 
 quires the consistency necessary 
 for moulding. The smaller the 
 depth of the pans in relation to 
 their superficies, the sooner is the 
 above-mentioned consistency ob- 
 tained. 
 
 The mass is now subdivided into 
 solids of a regular form by means 
 of a mould. This operation is 
 executed with rapidity. A moulder, 
 working by the piece, makes on an 
 average five thousand prisms a day, 
 which will measure 2 11 -8 cubic 
 feet. These prisms are arranged 
 on drying-shelves, where in a short 
 time they acquire the degree of 
 desiccation and hardness proper for 
 calcination. At Paris a mixture of 
 coke and coal is employed ; and 
 the common mode of burning by 
 slow heat rendered necessary by 
 that kind of combustible. 
 
 The artificial hydraulic limes are 
 intended to supply the place of the 
 natural ones in those countries 
 where the argillaceous limestone 
 is entirely wanting, and which are 
 commonly sold in Paris. 
 Lime-tree (the) is common in Europe, 
 attains considerable size, is very 
 light-coloured, fine and close in 
 the grain, and is used in the con- 
 struction of piano-fortes, harps, 
 etc. : it is particularly suitable for 
 
 2J9 
 
 carving, from its even texture and 
 freedom from knots. The works of 
 Gibbons at Windsor Castle, and 
 St. Paul's, London, are of the lime- 
 tree. 
 
 Limning, a term formerly applied to 
 portrait-painting, is drawing or 
 painting the body and limbs of the 
 human figure. 
 
 Linch-pin, the small pin, in'carts, etc., 
 that is put at the ends of the axle- 
 tree to confine the wheels on them 
 steadily. 
 
 Linear perspective is that which de- 
 scribes or represents the position, 
 magnitude, form, etc., of the se- 
 veral lines or contours of objects, 
 and expresses their diminution, in 
 proportion to their distance from 
 the eye. 
 
 Link-motion, a new apparatus for re- 
 versing steam-engines : it is used in 
 locomotive engines instead of the 
 reversing forks, and consists of a 
 link with a slot from end to end, 
 into which a guide-block fits, and 
 is connected to the slide-valve rod : 
 the rods of the two eccentrics are 
 connected one to each end of the 
 link, which is raised or lowered, or 
 held in a central position, by appa- 
 ratus attached to the centre of it, 
 moved by the reversing lever. 
 When the link is in a central po- 
 sition with regard to the slide- 
 valve rod, the guide-block remains 
 stationary, as it is then at the centre 
 upon which the link vibrates. When 
 the link is up, the guide-block is at 
 the lower end, and the slide receives 
 motion from the backward eccen- 
 tric. When the link is down, it 
 receives motion from the forward 
 eccentric. See plate 8, elaborately 
 drawn and explained in Vol. 79*, 
 in ' Rudimentary Series.' 
 
 Links, in locomotive engines, are flat 
 or round pieces of iron with round 
 holes at each end : they are used 
 to connect together, by bolts, dif- 
 ferent parts of the mechanism of 
 the engine. 
 
 Linseed oil has the fullest body and 
 dries better than anv of the three 
 
LIN 
 
 LOCKS. 
 
 LOG 
 
 oils (linseed, nut, and poppy) in use 
 with artists ; its colour is a stroflg 
 yellow, but this effect does not 
 arise from the action of the fire in 
 extracting the oil, but from the 
 pellicle which covers the grains, 
 and which contains a strong co- 
 louring matter soluble in oil. Lin- 
 seed oil, cold drawn, is equally 
 coloured with the other sorts, but, 
 like that of wax, this colour is 
 carried off by exposure to the sun. 
 
 Lintel, a piece of timber or stone 
 placed horizontally over a door- 
 way or window, to support the 
 superincumbent weight. 
 
 Lintel. " And ye shall take a bunch 
 of hyssop, and dip it in the blood 
 that is in the basin, and strike the 
 lintel and the two side-posts with 
 the blood that is in the basin ; and 
 none of you shall go out at the 
 door of his house until the morn- 
 ing/' Exodus xii. 22. 
 
 Liquid rubiate, or Liquid madder lake, 
 is a concentrated tincture of mad- 
 der, of the most beautiful and per- 
 fect rose-colour and transparency. 
 It is used as a water-colour only in 
 its simple state, diluted with pure 
 water, with or without gum ; it 
 dries in oil, by acting as a dryer 
 to it. Mixed or ground with all 
 other madder colours, with or with- 
 out gum, it forms combinations 
 which work freely in simple water, 
 and produce the most beautiful and 
 permanent effects. 
 
 Lithography, the art of drawing and 
 engraving onjstone, and taking im- 
 pressions from the same at press, 
 similarly to copper-plate printing, 
 but differing in manipulation. 
 
 Little winds, in mining, an under- 
 ground shaft, sunk from the hori- 
 zontal drift, by which the top of 
 the winds communicates with the 
 side or bottom of the great work- 
 ing-shaft, 
 
 Lloyd's Register. Lloyd's rules for 
 British and foreign shipping exert 
 a most essential and powerful in- 
 fluence on the construction and 
 science in the building of shipping 
 
 270 
 
 of this country as well as those of 
 continental and transatlantic mari- 
 time nations. Insurances from loss 
 can only be made at Lloyd's by 
 conforming to the rules laid down 
 by competent surveyors. See Vol. 
 5 i* in the ' Rudimentary Series.' 
 
 Load water-line, the mark on a ship 
 which the water makes when she is 
 loaded. 
 
 Loam, a natural mixture of sand and 
 clay : in the neighbourhood of 
 London, loam consists of fine red- 
 dish-grey sand 87 parts, alumina 
 13 parts = 100. 
 
 Local colours are such as faithfully 
 imitate those of a particular object, 
 or such as are natural and proper 
 for each particular object in a pic- 
 ture ; and colour is distinguished 
 by the term trial, because the place 
 it fills requires that particular co- 
 lour, in order to give a greater 
 character of truth to the several 
 colours around it. 
 
 Lock> a mechanical contrivance to 
 fasten a door, gate, or any place or 
 thing for security. A vast deal of 
 ingenuity has been exercised to 
 prevent false openings : keys of va- 
 rious kinds are made to fit the 
 wards (interior contrivances), and 
 prevent what is called picking, the 
 key being made only to suit that 
 belonging to the possessor. 
 
 Lock, in inland navigation, a portion 
 of a canal confined between a sluice- 
 gate and a flood-gate, to facilitate 
 the passage of boats in ascending 
 or descending planes. 
 
 Lockrand, a course of bond stones, or 
 a bonding course, in masonry. 
 
 Locks for canal and river navigation. 
 The earliest approximation to what 
 is now known by the name of lock, 
 consisted of a simple dam formed 
 across the bed of a river, so as to 
 raise the water to such a height as 
 to allow vessels to float along it. 
 Where the river had a considerable 
 fall with a strong current, it was 
 necessary to have these dams at 
 short distances from each other, 
 otherwise the requisite depth of 
 
LOG 
 
 LOCKS. 
 
 LOG 
 
 water could not be obtained. As 
 the whole space between two of 
 these dams was in fact the lock, 
 it was necessary, in passing from 
 one level to another, to run down 
 the water for the whole of that 
 distance, thereby causing consider- 
 able delay, and a waste of water 
 that would now be considered a 
 serious evil. In China these dams 
 are common, and they have also 
 been used on the Continent. See 
 Vol. 1 2 1 of the 'Rudimentary Series.' 
 Locks with a double set of gates, but 
 no chamber-walls, are now of ordi- 
 nary construction. The evils at- 
 tendant on the dams formerly 
 constructed were in a great mea- 
 sure removed by the introduction 
 of double sets of gates or sluices, 
 the upper set being constructed so 
 near to the lower as only to leave 
 room enough for the vessel or ves- 
 sels to float between them. Framed 
 gates were also used instead of se- 
 parate beams and planks, because 
 the space to be emptied or filled 
 was so small that a very short time 
 was required to pass the water, 
 and there was no stream of suffi- 
 cient strength to prevent their 
 being easily opened. Where these 
 locks are intended for rivers, it is 
 usual to make a side cut or arti- 
 ficial canal for the purposes of the 
 navigation, and to leave the river- 
 course for the passage of the sur- 
 plus water. A quick bend of the 
 river is generally chosen for one of 
 these cuts ; and to keep the water 
 in the upper part of the river to a 
 sufficient height for navigation, a 
 dam or weir is made across the old 
 river-course at or below the point 
 where the artificial cut quits it. 
 The lock is then built at the most 
 convenient part of the cut, and its 
 fall made equal to the difference in 
 the levels of the water at the top 
 and at the bottom of the dam or 
 weir. When a vessel is going up 
 the river, she floats along the cut, 
 and passes between the lower gates 
 into the lock ; the lower gates are 
 
 271 
 
 then closed, and the valves or 
 paddles of the upper gates being 
 opened, the water flows into the 
 lock, and rises to the level of the 
 upper part of the river ; the upper 
 gates are then opened, and the 
 vessel floats out of the lock. The 
 reverse of this operation conducts 
 a vessel down the river. 
 
 The abutments for the gates have 
 been made of timber, brickwork, 
 and masonry ; but when the double 
 set of gates was first introduced, it 
 was usual to leave the space be- 
 tween the upper and lower gates 
 unprotected by either timber or 
 any kind of building. Of course 
 the agitation of the water in the 
 lock was constantly washing away 
 the earthen banks, thereby causing 
 a risk of their being broken down 
 by such continued weakening ; and 
 by enlarging the space between the 
 two sets of gates, it occasioned a 
 loss of time in emptying and filling, 
 as well as a waste of water. 
 Lock (common modern canal}. The 
 difference of altitude between the 
 upper and lower levels, where the 
 locks are constructed, varies ac- 
 cording to local circumstances. 
 Where the ground is longitudinally 
 steep and water plentiful, the locks 
 are generally made of greater lift 
 or fall than where the ground is 
 comparatively flat and water scarce. 
 It is evident, that where the super- 
 ficial area of locks is the same, one 
 having a rise of 12 feet would re- 
 quire twice the quantity of water 
 to fill it that would be requisite for 
 one of 6 feet. Having many locks, 
 however, of small lifts, instead of a 
 few of greater, increases the ex- 
 pense, as well as the time for pass- 
 ing them. 
 
 For narrow canals these locks 
 are generally made about 80 feet 
 long, and !\ to 8 feet wide in the 
 chamber. On the Caledonian canal 
 they are 180 feet long, 40 feet wide, 
 and 30 feet deep. Locks are also 
 made of every intermediate size. 
 
 Lock-gates have till lately been 
 
LOG 
 
 LOCKS. 
 
 LOG 
 
 made of timber; but in consequenqp 
 of the difficulty of procuring it of 
 sufficient size for those on the 
 Caledonian canal, cast-iron was 
 partially adopted for the heads, 
 heels, and ribs. Iron gates, cast in 
 one piece, have been used on the 
 Ellesmere canal, as well as others 
 with cast-iron framing and timber 
 planking. 
 
 Locks with side ponds. When water 
 is scarce, it is common to construct 
 side ponds, by which a considerable 
 portion (in general one - half) is 
 saved. The usual number of these 
 ponds is two ; for it has been de- 
 termined by experience, that when 
 a greater number has been made 
 use of, the loss occasioned by leak- 
 age and evaporation has sometimes 
 been more than equal to the ad- 
 ditional quantity of water thus re- 
 tained. 
 
 Locks for the transit of vessels of 
 different sizes. Where vessels of 
 different sizes have to pass the 
 same locks, three pairs of gates are 
 sometimes placed instead of two, 
 the distance between the upper 
 and lower pairs being sufficient to 
 admit the largest vessels, and that 
 between the upper and middle pairs 
 being adapted to the smaller class. 
 By this contrivance, when a small 
 vessel is to be passed through, the 
 lowest pair of gates is not used; and 
 when a large vessel goes through, 
 the middle pair of gates is not 
 worked. Thus it is evident that 
 the quantity of water contained 
 between the middle and lower pair 
 of gates is saved when a small ves- 
 sel passes, compared with what 
 would be required were the middle 
 set of gates omitted. 
 
 Locks (parallel double - transit}. 
 Where the transit is great, much 
 time and water may be saved by a I 
 double-transit lock, which is two | 
 locks placed close to and parallel 
 with each other, with a communi- 
 cation between them, which can be 
 opened or cut off at pleasure by 
 valves or paddles. 
 
 272 
 
 As one of these locks is kept full 
 and the other empty, a vessel in 
 descending floats into the full one: 
 the upper gates are then closed, 
 and the water is run, by means of 
 the connecting culvert, into the 
 empty lock (the gates of which 
 were previously closed), till the 
 water in the two locks is on the 
 same level, which will be when 
 each is half-full: the connecting 
 paddles are then closed, and the 
 remaining half of the water in the 
 descending lock is run into the 
 lower canal. The next descending 
 vessel has to be floated into the 
 lock which remains half-filled, and 
 which consequently requires only 
 half a lock of water to be run from 
 the upper pond to raise it to the 
 proper level, and then that half is 
 transferred to the lock previously 
 used, to serve the next descending 
 vessel ; but supposing a vessel to 
 be ascending after the first descent, 
 it will enter the empty lock, and 
 receive a quarter-lock of water from 
 that which remained half-filled: of 
 course, three-quarters of a lock of 
 water is now required from the 
 upper canal to complete the filling. 
 If a descending vessel next follows, 
 it enters the full lock, and its water 
 is run into the lock which was 
 previously left a quarter-full; and 
 when both have arrived at the same 
 level, it is evident they will be each 
 five-eighths full, and the succeeding 
 descending vessel will require only 
 three-eighths of a lock of water 
 from the upper pond or canal. 
 From these observations, it will be 
 seen that the double-transit lock 
 saves nearly one-half of the water 
 which a common single lock would 
 require. 
 
 Sometimes the two parallel locks 
 are made of different sizes, to suit 
 the various descriptions of vessels 
 that may have to pass. 
 Locks connected longitudinally, com- 
 monly called a Chain of Locks. 
 When loss of water is of no conse- 
 quence, a considerable expense is 
 
LOG 
 
 LOCOMOTIVE ENGINES. 
 
 LOG ! 
 
 sometimes saved by placing the 
 locks close together, without any 
 intermediate pond ; for by passing 
 from one immediately into the 
 other, there is only required one 
 pair of gates more than the number 
 of locks so connected, besides a 
 proportionate saving of masonry. 
 Thus eight connected locks would 
 only require nine pairs of gates ; 
 whilst if they were detached, they 
 would require sixteen pairs. But 
 to show that these cannot be adopt- 
 ed with propriety excepting where 
 water is abundant, it is necessary 
 to observe, that every two alternate 
 ascending and descending vessels 
 will require as many lockfuls of 
 water as there are locks : for in- 
 stance, if a vessel has just ascended, 
 it has left all the locks full ; a de- 
 scending vessel then enters the 
 upper lock, and when its gates are 
 closed, the water is run down : but 
 all the locks below being previously 
 filled, they cannot contain it, and 
 it consequently passes over the 
 gates or weirs of all of them into 
 the lower canal : the vessel has by 
 this means descended to the level of 
 the second lock, the water in which 
 must also be run into the lower 
 canal, for the same reason as al- 
 ready stated. When the water of 
 all the locks has thus been run 
 down, au ascending vessel will re- 
 quire all these locks to be filled 
 from the upper canal, which, how- 
 ever, will be retained in the locks 
 ready for the succeeding vessel to 
 pass down. From this it will be 
 evident, that where eight locks 
 are connected, a descending vessel 
 draws no water from the upper 
 canal, because the locks are pre- 
 viously all filled, but it empties 
 eight locks of water into the lower 
 canal : an ascending vessel, on the 
 contrary, empties no water into 
 the lower canal, because all the 
 locks were previously emptied, but 
 it draws eight lockfuls from the 
 upper canal, in order to fill them : 
 consequently, the passing of one 
 
 ascending vessel, and one descend- 
 ing, requires the expenditure of 
 eight lockfuls of water. 
 
 Other modes of passing vessels 
 from one level to another, by sub- 
 stituting machinery, either wholly 
 or in part, have been adopted ; but 
 these have either failed entirely, or 
 have not been brought into general 
 use. 
 
 Locomotive Steam-engines, a class of 
 travelling machines adapted either 
 for railways or common roads, 
 were originally designed for the 
 latter, but did not succeed ; and 
 roads were then made for them, 
 called railways, on which they have 
 been most successful. The principle 
 of action being the same in both 
 kinds, a description of the railway 
 variety will explain the manner in 
 which progressive motion is obtain- 
 ed by the agency of steam. 
 
 Locomotion or progression is the 
 combined effect of a number of 
 parts in each engine performing 
 separate duties. The principal of 
 these parts and the plan of their 
 co-operation may be thus classed : 
 1st. The parts which generate the 
 
 steam. 
 2nd. The parts which regulate the 
 
 employment of the steam. 
 3rd. The parts by which the driver 
 controls the action of the engine. 
 4th. The parts immediately con- 
 cerned in producing locomotion. 
 5th. The parts which excite the 
 
 rapid combustion of the fuel. 
 6th. The parts which supply water 
 
 to the boiler. 
 7th. The parts which support the 
 
 engine on the rails. 
 8th. The manner in which loco- 
 motion is produced by these parts. 
 In explaining them and their 
 effect as thus arranged, we have 
 
 1st. The parts which generate 
 the steam, called the boiler, con- 
 taining internally a fire-box, varying 
 according to the dimensions of the 
 engine from 25 (as in the ' Rocket') 
 to 303 small tubes (as in the broad- 
 gauge engines), a regulator, and 
 
LOG 
 
 LOCOMOTIVE ENGINES. 
 
 LOG 
 
 a steam-pipe. Externally, a chiui- 
 ney and two safety-valves are fixed 
 to the boiler. 
 
 2ndly, The parts which regulate 
 the employment of the steam are,two 
 slide-valves (covering the passages 
 to and from the cylinders), attached 
 to two sets of ' valve-gear,' worked 
 by two eccentrics for the ' forward' 
 and two other eccentrics for the 
 ' backward' motion of the engine ; 
 but only two of them work at one 
 time, the other two being what is 
 called ' out of gear.' Four rods 
 called eccentric-rods, encircling the 
 eccentric-sheaves at one end, and 
 jointed to the slide-valve gear at 
 the other end, complete the con- 
 nection of the slide-valves to the 
 eccentrics fixed on the axle of the 
 driving-wheels. 
 
 Srdly, The parts by which the 
 driver controls the action of the 
 engine are, three sets of levers and 
 rods connected to the slide-valve, 
 eccentric-rods^regulator-valvesjand 
 feed-pipe cocks, whereby he can 
 ' put on' or 'shut off' steam to the 
 cylinders, water to the boiler, or 
 place the slide-valves in a ' for- 
 ward' or 'backward' position at 
 his pleasure. These arrangements 
 are usually called the ' hand-gear.' 
 
 4thly, The parts immediately con- 
 cerned in producing locomotion 
 are, two cylinders, on which work 
 two steam-tight pistons, fixed on 
 the end of the piston-rods. On the 
 open end of the piston-rods are 
 also fixed T-pieces, called cross- 
 heads, which slide between or 
 round guide-bars, called motion- 
 bars, fixed parallel with the cylin- 
 ders. By this means the pistons 
 can only move in a right line with 
 the cylinders. Two strong rods, 
 called connecting-rods, attach the 
 cross-heads to the driving-wheels, 
 or to a cranked axle when there is 
 one used. Whether the pistons 
 are connected to a cranked axle or 
 to the arms of the driving-wheels, 
 this connection is always made at 
 an angle of 45 degrees to each 
 
 other ; therefore the one piston is 
 in the centre of the cylinder exert- 
 ing its greatest power during that 
 part of the stroke when the other 
 piston is at the end of the cylinder 
 exerting no power. (This excel- 
 lent arrangement was amongst the 
 first improvements introduced by 
 the late Mr. G. Stephenson, in 
 1814, who thus placed the locomo- 
 tive in the same high position, as to 
 efficiency, as was previously done 
 for fixed engines by Watt.) The 
 connection being thus completed 
 between the pistons and the driv- 
 ing-wheels, it is evident that any 
 movement of the one must imme- 
 diately act upon the other. 
 
 5thiy The parts which excite the 
 rapid combustion of the fuel re- 
 quired in locomotive engines are, 
 the chimney and a pipe called the 
 blast-pipe, so made as to cover the 
 exhausting passages from both cy- 
 ' linders, and terminating in the 
 centre of the chimney, near the 
 level of the top of the boiler. It 
 is the escape, through this pipe, 
 of each succeeding cylinderful of 
 steam, or that portion of it allowed 
 to escape by the slide-valves, which 
 causes the ' beats ' or ' pulsations ' 
 so distinctly audible when the 
 locomotive is at work. 
 
 6thly, The parts which supply 
 water to the boiler are, two force- 
 pumps, connected by two feed- 
 pumps to the boiler, and to a re- 
 servoir of water. The pumps are 
 worked either from the cross-head, 
 or from eccentrics on the axle of 
 the driving wheels. 
 
 7thly, The parts which support 
 the engine are, 2, 4, or 6 wheels, 
 besides the driving-wheels, a set of 
 springs, and a strong frame on 
 which the boiler and machinery are 
 securely fixed. 
 
 Sthly, The manner in which lo- 
 comotion is produced from the co- 
 operation of these several parts is 
 as follows. The boiler is filled 
 with water until it completely sur- 
 rounds all the tubes and inside fire- 
 
 274 
 
LOG 
 
 LOCOMOTIVE ENGINES. 
 
 LOG 
 
 box. Fire is then applied, and in 
 due time steam is generated from 
 the water and collected between 
 the surface of the water and the 
 top of the boiler, until it has 
 reached the pressure required. On 
 the regulator being then opened, 
 and the slide-valves placed in their 
 working position by the driver, the 
 steam passes from the boiler through 
 the steam-pipe to the cylinders, 
 where its force moves the pistons, 
 which, being attached to the driv- 
 ing-wheels (as has been explained), 
 causes them to revolve, and thus 
 produces locomotion. The slide- 
 valves and pumps being wrought 
 from some part set in motion by 
 the piston, regulate the admission 
 of steam to the cylinder, and of 
 water to the boiler. When the 
 steam has moved the piston to the 
 end of the cylinder, a passage is 
 opened for its escape to the atmo- 
 sphere through the blast-pipe, and 
 the velocity of this escaping steam 
 creates a partial vacuum in the 
 chimney, causing a rush or ' blast ' 
 of air through the fire to fill this 
 vacuum ; which blast excites the 
 rapid combustion of the fuel, and 
 consequent rapid generation of 
 steam. This completes the duties 
 of one admission of steam to the 
 cylinders, until its escape to the 
 atmosphere ; and when this escape 
 has taken place, another admission 
 of steam, to the opposite side of 
 the piston, forces it back to the 
 other end of the cylinder ; and by 
 the medium of the crank, the re- 
 ciprocating motion of the piston is 
 converted into a rotatory one, and 
 the locomotion begun by the first 
 admission of steam to the cylinders 
 is continued by the second and 
 succeeding admissions.- 
 
 The repetition of these simple 
 operations has amazed and gratified 
 the world, by safely conveying 
 heavy passenger-trains at upwards 
 of 70 miles an hour, and merchan- 
 dise trains of 600 tons weight at 
 25 miles per hour ! the mere idea 
 
 of which, not many years since, 
 would have been regarded as purely 
 fabulous. 
 
 Such is the modern railway loco- 
 motive, an illustrative example of 
 the genius of man ; but, like other 
 important inventions, it is the 
 joint production of many minds, 
 and many more are still directed 
 to its further improvement. The 
 records of the Patent Office show, 
 that from January, 1840, to the 
 end of September, 1849, no less 
 than 226 patents were enrolled, all 
 of them more or less applicable 
 to the steam-engine and its ap- 
 pendages. Of these 226 patents, 
 45 were enrolled during the first 
 nine months of 1849. It has been 
 remarked that steam-engines and 
 railways were too matter-of-fact 
 subjects for poets and painters; but 
 from the above record it is evident 
 that they deeply impress them- 
 selves upon the inventive intellect 
 of the world ; and if the prodigies 
 performed by stearri remain un- 
 sung or unportrayed, they dare, if 
 not realize, the very sublimity of 
 both poetry and painting ; for what 
 more interesting scene to delineate 
 than one of these stately machines 
 moving safely along, at eagle-speed, 
 the very elite of the land (including 
 even the Royal Family), through 
 districts rich in the historical as- 
 sociations of past ages, and still 
 teeming with the works of nature 
 and of art ! Surely it cannot be 
 that the subject is too lofty a one 
 for poetical or pictorial illustration, 
 for in greatness of idea lies the 
 success of both. 
 
 A brief review of the progress of 
 locomotive engines is all that can 
 be here given. It is now about 
 2000 years since the powers of 
 steam were recorded by Hero of 
 Alexandria, but it is only 200 years 
 (in 1650) since it was first usefully 
 employed by the Marquis of Wor- 
 cester. The first idea of using it 
 for propelling carriages is generally 
 ascribed to Dr. Robison, in 1759, 
 
LOG 
 
 LOCOMOTIVE ENGINES. 
 
 LOG 
 
 when it was suggested by him to 
 Watt,who included a steam -carriage" 
 in hispatentsof 1769 and 1784, but 
 never carried them out. In 1786, 
 Oliver Evans, of Philadelphia, had 
 clear perceptions of the advantages 
 of applying steam to waggons, 
 boats, and mills ; but the want of 
 friends and means compelled him 
 to confine his exertions to steam- 
 mills. From 1802 to 1805, Trevi- 
 thick applied steam-carriages to 
 both common roads and railways, 
 with considerable success for first 
 experiments ; and his engine, with 
 Stephenson's improvements, is now 
 the modern locomotive. About the 
 year 1803, it appears that a Mr. 
 Fredericks also made a steam-en- 
 gine for a silver mine in Hanover, 
 which, in 1811, was employed to 
 convey their Majesties and suite of 
 Westphalia over the mineral rail- 
 way at considerable speed. This 
 was probably the first royal trip on 
 a railway. From 1805 up to 1814, 
 invention was directed to ensure 
 the adhesion of the wheels upon 
 the rails ; and many ingenious plans 
 were tried, some of which succeeded 
 well at slow speeds, but were not 
 calculated for high velocities. In 
 1814, however, Mr. Blackett, of 
 the Wylam Railway, reverting to 
 Trevithick's plan, fully established 
 the FACT, that on a level, or mo- 
 derately inclined railway, the ad- 
 hesion of a smooth iron wheel upon 
 a smooth iron rail was sufficient 
 to draw heavy loads. He tried both 
 six and eight wheeled engines. In 
 1814, Mr. Stephenson introduced 
 two cylinders, or two complete 
 steam-engines, to one locomotive. 
 From this time up to 1829, the 
 powerful opposition of the owners 
 of other modes of conveyance 
 greatly retarded the progress of j 
 the locomotive engine; and so | 
 strong was the feeling that they 
 were not economical, that both 
 Mr. Walker and Mr. Rastrick re- 
 ported against them, in 1829. 
 These reports, and one of a doubt- 
 
 ful character by Telford, led to the 
 offer of a prize of 500, in 1829, 
 by the directors of the Liverpool 
 and Manchester Railway, for the 
 best locomotive engine, whose 
 weight was not to exceed six tons. 
 This proceeding gave an important 
 impulse to locomotives, and ended 
 in establishing their superiority 
 over all other existing systems of 
 travelling. Five competitors ap- 
 peared, namely, Messrs. Stephen- 
 son, Erickson, Hockworth, Burstal, 
 and Brandreth. The machinery of 
 the two last was not suitable, and 
 did not proceed to trial. Mr. 
 Stephenson's ' Rocket,' Mr. Erick- 
 son's ' Novelty,' and Mr. Hock- 
 worth's ' Sanspareil,' were all tried, 
 and the prize was fairly won by the 
 ' Rocket,' which, after the trials 
 were over, reached a speed of 35 
 miles per hour, and the ' Novelty' 
 about 24 miles per hour. 
 
 The ' Rocket ' embraced the fire- 
 box, tubes, and blast-pipe of the 
 modern locomotive. 
 
 The ' Novelty ' embraced the 
 plan now much used on short lines, 
 of carrying engine, fuel, and water, 
 all on one frame. 
 
 The ' Sanspareil ' embraced the 
 blast-pipe of the modern engine, 
 with the single returned tube of the 
 older locomotives. From this it 
 will be seen that this competition 
 at once brought out the leading 
 features which have since rendered 
 the locomotive engine so popular 
 throughout the world. 
 
 From 1830,uptotheintroduction 
 of the 7-feet gauge on the Great 
 Western Railway, in 1838, no 
 marked improvement took place in 
 the locomotive, but the rivalry 
 which sprang up between the 
 gauges served greatly to develope 
 their capabilities. 
 
 Engines of a novel construction, 
 having the boiler on one frame, and 
 the machinery on another frame, 
 were tried on the Great Western 
 Railway ; also engines embracing 
 Trevithick's plan of working the 
 
 276 
 
LOG 
 
 LOCOMOTIVE ENGINES. 
 
 LOG 
 
 driving-wheels by toothed wheels, 
 fixed on a separate cranked axle, 
 were tried, but all abandoned for 
 engines modelled from one of 
 Stephenson's ; and the last new 
 Great Western engines only follow 
 up his latest improvements and 
 Gray's expansive slide-valve motion 
 on a large scale. 
 
 A number of patents have been 
 enrolled for improving the loco- 
 motive engine, but a few only have 
 been reduced to practice. 
 
 Amongst the more conspicuous 
 of them are, Mr. Stephenson's im- 
 provements in the slide-valve mo- 
 tion ; Mr. Gray's expansive mo- 
 tion ; Mr. Crampton's arrangement 
 of wheels ; Mr. Bodmer's arrange- 
 ment of four pistons in two cylin- 
 ders ; Mr. M'Connell's tank engine ; 
 Mr. Samuel's express engine; and 
 Mr. Adam's steam-carriage. The 
 improvements in the mechanism of 
 the slide-valve motion, by Messrs. 
 Stepbenson and Gray, have been 
 widely adopted. Mr. Crampton 
 has engines of his plan at work 
 both in England and on the Con- 
 tinent, which enable high driving- 
 wheels to be used on the narrow 
 gauge, without raising the centre 
 of gravity. (For popular descrip- 
 tion and illustration, see Vols. 78* 
 and 79* in ' Rudimentary Series.') 
 
 Mr. Bodmer's plan is to admit 
 the steam between two pistons in 
 one cylinder acting on two cranks, 
 so as to compensate the strain on 
 the frame and machinery. His 
 engines work steadily, and are in- 
 genious in construction. 
 
 The tank engine carries on the 
 same frame water and fuel, its tank 
 for water being placed on the top 
 of the boiler. This is the plan 
 adopted on the Great Western Rail- 
 way ; but on narrow-gauge lines 
 the tank is usually placed below 
 the boiler and framing, a better 
 arrangement, where the machinery 
 permits it to be done. 
 
 Mr. Samuel's express engine 
 weighed only 25 cwt., and con- 
 
 265* 
 
 veyed seven passengers at the rate 
 of 30 miles per hour on the Eastern 
 Counties Railway. 
 
 Mr. Adam's steam-carriage is on 
 this plan, with a very handsome 
 carriage for passengers, all on one 
 frame, and has been tried on some 
 of the branch railways of both 
 gauges. 
 
 Having thus briefly glanced at 
 the progress of the locomotive en- 
 gine, it only remains as briefly to 
 notice some important discussions 
 which have agitated the mechani- 
 cal world regarding them. 
 
 From the earliest introduction of 
 locomotives, four, six, or eight 
 wheels appear to have been used, 
 according to the designs of the ma- 
 kers; but about 1840-1-2, an ani- 
 mated discussion of the respective 
 merits of the four and six wheeled 
 engines was carried on in the co- 
 lumns of the railway press. Both 
 classes have their merits, and both 
 classes had able advocates, but pub- 
 lic opinion evidently tended in fa- 
 vour of the six- wheeled engine as 
 the safer of the two under all con- 
 tingencies : hence the greater pro- 
 portion of the present locomotives 
 have six wheels. 
 
 The gauge controversy of 1845 
 6-7-8 led to the re-introduction of 
 eight - wheeled engines on both 
 gauges, weighing about 36 tons 
 each, which realized speeds of about 
 sixty and seventy miles per hour. 
 The weight of these monster en- 
 gines, it will be observed, is more 
 than eight times that of the' Rocket' 
 (4-^ tons), which won the prize in 
 1 829, whilst the speed is only twice 
 that of the Rocket ' (thirty-five 
 miles) at that time. It is worthy 
 of remark, that in 1829 the exist- 
 ing engines of 10 to 16^ tons were 
 considered as far too heavy, and the 
 Liverpool and Manchester directors 
 bound competitors not to exceed six 
 tons weight. In 18 49, the same feel- 
 ing prevailed, and the injury done 
 to the railway by these 36-ton en- 
 gines is much complained of, and 
 
LOG 
 
 LOCOMOTIVE ENGINES. 
 
 LOG 
 
 tank engines and steara-carriagjes 
 embody this feeling in practice. 
 
 A description of the locomotive 
 can scarcely be closed without no- 
 ticing the death of its great im- 
 prover, Mr. G. Stephenson, who 
 died in 1848, aged 68 years. 
 
 He found the locomotive a very 
 imperfect machine ; he left it in that 
 efficient state that even the daring 
 genius of a Brunei could only copy 
 his plans for the 7 -feet gauge. This 
 is another testimony to that far- 
 seeing intellect which so early 
 grasped the principal requisites for 
 an efficient locomotive, and whose 
 genius coped with and overcame 
 the leading engineers of England, 
 in 1829, by establishing both loco- 
 motives and the Liverpool and 
 Manchester Railway against all op- 
 position, and from which sprang 
 that system of railways which has 
 added so immensely to theresources 
 of the nation ay, of the world. 
 
 Civil services, military services, 
 naval services, and no services, have 
 at all times been liberally rewarded 
 by the Crown and Legislature ; 
 but there are no such rewards, no 
 ORDER OF MERIT for such men as 
 the Stephensons,Watt, Arkwright, 
 Field, the Kennies, Whitworth, 
 etc., who are the mainstays of our 
 progress, our greatness, and our 
 power. This is wrong very wrong, 
 and ought to be amended. How- 
 ever, if the Crown forget, and 
 the Legislature neglect such men, 
 it is consolatory to know, that their 
 names will be embalmed in the 
 hearts of the people, whilst the 
 profligacy of honours and rewards 
 to those having no real claim on 
 the gratitude of the nation is uni- 
 sally condemned. 
 
 Upon the Taunus Railway, an 
 apparatus is in use, which, from its 
 simplicity and efficiency, cannot 
 easily be excelled. It is attached 
 to the hinder part of the tender, 
 and is used in case of emergency, 
 as well as being constantly used 
 when at the stations, where it is 
 
 necessary to uncouple the engine 
 and tender from the train, thereby 
 saving great trouble, and with less 
 danger to engine-men and fire-men, 
 as they can disconnect at any speed 
 or at any time, whether the engine 
 and train are in motion or not. (For 
 a better elucidation of this simple 
 and ingenious contrivance, see the 
 work on the ' Taunus Railway, '4 to.) 
 
 Locker, a small closet or cupboard : 
 lockers were used in churches to 
 hold sacred relics. 
 
 Locust-tree (the) of North America is 
 of a greenish yellow ; is tough and 
 durable, and used for trenails for 
 ships, for posts, stakes, paling, etc. 
 
 Lode, in mining, a vein of ore. 
 
 Loft, a room in the roof of a build- 
 ing ; a store-room in a theatre ; a 
 depository for hay and corn in a 
 stable : a music-loft ; a singing-loft ; 
 a rood-loft in a church. 
 
 Lofty tin, rich, massive, and rough 
 tin. 
 
 Log, in navigation, a small triangular 
 piece of board balanced by a thin 
 plate of lead so as to swim perpen- 
 dicularly, and, being fixed to a line, 
 measures the ship's way. 
 
 Logarithms are the artificial numbers 
 used to facilitate or abridge arith- 
 metical calculations, and may be 
 considered as expressing the rela- 
 tion between an arithmetical and 
 geometrical series of terms, or 
 between ratios and the measures of 
 ratios, and are the indices or expo- 
 nents of a series of numbers in geo- 
 metrical progression. The origin 
 and nature of logarithms may be 
 easily explained. 
 
 In arithmetical series the quan- 
 tities increase or decrease by the 
 same difference, but in a geome- 
 trical series they increase or dimi- 
 nish by a common measure. The 
 first of the following lines exhibits 
 an arithmetical progression ; all the 
 other lines are examples of geome- 
 trical progression. 
 10, 1, 2, 3, 4, 5, 6, 7, 8, 9. 
 21, 2, 4, 8, 16, 32, 64, 128, 256, 
 512. 
 
 266* 
 
LOG 
 
 LOMBARDIC SCHOOL. 
 
 LOR 
 
 31, 3, 9, 27, 81, 243, 729, 2187, 
 
 6561, 25683. 
 
 41, 10, 100, 1000, 10,000, etc. 
 Here consider the upper line as 
 the index to all the rest ; every 
 term of it is the logarithm of a 
 corresponding term in each of 
 them ; and it is evident that an 
 infinitude of other lines, or any one 
 of the same lines, varying the point 
 of commencement, and containing 
 numbers in geometrical progres- 
 sion, might be added, to all of which 
 the same arithmetical series might 
 furnish logarithms. M. Thoman, 
 an ingenious French mathemati- 
 cian employed by the Co. Credit 
 Mobilier of Paris, has compiled a 
 series of logarithmic tables to cal- 
 culate the values and interests of 
 moneys at every \ and ^ per cent. 
 
 Logeum, the pulpitum or wooden 
 stage of a theatre, placed upon the 
 proscenium or permanent stage. 
 In the Greek theatre the pulpitum 
 extended into the orchestra beyond 
 the proscenium. 
 
 Logium, a hovel or outhouse. 
 
 Logwood, from Campeachy, Jamaica, 
 Honduras, etc., is largely used as a 
 purple or dark-red dye-wood. 
 
 Lomazzo (Gio. Paolo) of Milan, pupil 
 of Cerva of Milan ; he published his 
 treatise on painting in 1584, and 
 which he condensed in his idea of 
 the ' Temple of Painting,' printed 
 in 1590. 
 
 Lombardic Architecture, a style which 
 immediately succeeded the decline 
 of the Roman style. 
 
 Lombardic School of Painting. The 
 distiuguishingcharacteristicsofthis 
 school are, grace, an agreeable taste 
 for design, without great correct- 
 ness, a mellowness of pencil, and 
 a beautiful mixture of colours. An- 
 tonio Allegri, called Correggio, was 
 the father and the greatest orna- 
 ment of this school : he began by 
 imitating nature alone, but as he 
 was chiefly delighted with the 
 graceful, he was careful to purify 
 his design; he made his figures 
 elegant and large, and varied his 
 
 267* 
 
 outlines by frequent undulations, 
 but was not always pure and cor- 
 rect, though bold in his concep- 
 tions. Correggio painted in oil, a 
 kind of painting susceptible of the 
 greatest delicacy and sweetness ; 
 and as his character led him to 
 cultivate the agreeable, he gave a 
 pleasing, captivating tone to all his 
 pictures. 
 
 London and Nottingham whites. The 
 best of these do not differ in any 
 essential particulars materially, nor 
 from the white leads of other ma- 
 nufactories. The latter, being pre- 
 pared from flake-white, is gene- 
 rally the greyest of the two. The 
 inferior white leads are adulterated 
 with whiting or other substances, 
 which injure them in body and 
 brightness, dispose them to dry 
 more slowly, to keep their place 
 less firmly, and to discolour the oil 
 with which they are applied. All 
 the above are carbonates of lead, 
 and liable to froth or bubble when 
 used with aqueous, spiritous, or 
 acid preparations. 
 
 Longitude, length ; the distance of 
 any part of the earth, east or west, 
 from London, or any other given 
 place. 
 
 Long timbers, in ship-building, those 
 timbers in the cant bodies which 
 reach from the dead-wood to the 
 second futtock-head. 
 
 Loots, tin slime or sludge. 
 
 Loof, in navigation, pronounced luff, 
 a term applied when a ship going 
 large before the wind, is brought 
 close by the wind ; to put the helm 
 towards the lee-side. 
 
 Loop, a part of a block of cast-iron, 
 broken or melted off from the rest. 
 
 Loop, a rail of bars joined together 
 like a gate, to be removed in and 
 out at pleasure. 
 
 Loop, a hinge of a door. 
 
 Loop-hole, a narrow opening or cre- 
 nelle used in the battlements of the 
 castles of the early English. 
 
 Lord of the land or tree, in Cornwall, 
 the person in whose land the mine 
 is ; therefore the part which he re- 
 
LOR 
 
 MACHINERY. 
 
 MAC 
 
 serves to himself for liberty to wojk 
 a mine in his land is the one-sixth, 
 one-seventh, one-eighth, or any 
 other proportion, free of expense, 
 
 and called the ' dues' dish.' 
 
 Lorication, the filling of walls with 
 mortar. 
 
 Louvre, a lantern ; a turret on the 
 roof of an ancient hall or kitchen 
 for the escape of smoke and for 
 ventilation, now made an orna- 
 mental and pleasing object. 
 
 Low-pressure engine. (See Steam- 
 engine.) Low-pressure steam- 
 engine is when the steam-engine 
 
 . *is worked at a low pressure of 
 steam, when the steam is drawn 
 off into a condenser apparatus. 
 
 Loxodromics, art of oblique sailing 
 by the rhomb, which always makes 
 equal angles with every meridian. 
 
 Lozenge, in geometry called a rhomb, 
 and when the sides are unequal, a 
 rhomboid ; in heraldry, a four-cor- 
 
 nered figure, resembling a pane of 
 glass in old casements. 
 
 Lozenge moulding, a name given to 
 the Norman style of mouldings and 
 ornaments, which are shaped like 
 lozenges. 
 
 Lubricate,to make smooth or slippery. 
 
 Lubricator, an oil-cup or other con- 
 trivance for supplying oil or grease 
 to rubbing surfaces, in order to 
 diminish friction. 
 
 Lucerna, an oil-lamp. The Greeks 
 and Romans originally used can- 
 dles ; but in later times these 
 were chiefly confined to the houses 
 of the lower classes. 
 
 Lugsail, in navigation, a small sail 
 hoisted occasionally on the mast 
 of a boat or small vessel. 
 
 Lychnus, a lamp suspended, or a pen- 
 dent light. 
 
 Lt/sis, some member above the corona 
 of a podium, introduced in temples, 
 and in the scene of a theatre. 
 
 M. 
 
 MACHINE ORGANA, defined by Vi- 
 truvius, in his 10th book, as con- 
 trivances for the concentration and 
 application of force, which are 
 known by the names of instru- 
 ments, mechanical powers, ma- 
 chines, engines, etc. 
 
 Machinery, a general term applied to 
 mechanical combinations of parts 
 for creating power, or producing 
 works which may otherwise be, 
 more or less perfectly, made with 
 the hands. The first class of these 
 combinations is usually distin- 
 guished by the name of engines ; 
 the second, by that of machines. 
 
 Engines, or machines for crea- 
 ting or accumulating and applying 
 power, are distinguished from each 
 other according to the material 
 employed in the creation of their 
 power, as air-engines, water-en- 
 gines, gas-engines, steam-engines, 
 electric engines, etc. 
 
 Machines employed in the ma- 
 nufacturing arts are named accord- 
 ing to their products, as lace-ma- 
 
 chinery , rope-machinery, paper-ma- 
 chines ; or to the processes they 
 perform, as spinning-machinery, 
 printing-machinery, sawing-ma- 
 chinery, etc. 
 
 The materials of which machine- 
 ry is composed are, wood of various 
 kinds, iron, brass, copper, and 
 other metals, with flexible materials 
 for bands, cords, etc., as wool, 
 caoutchouc, and leather. 
 
 The several parts of machinery 
 are, frames, plummer-blocks, car- 
 riages, bolts and nuts, pins, shafts, 
 wheels, pinions, levers, cranks, 
 springs, screws, pulleys, riggers, 
 bands or belts, and cords, etc., 
 studs, tappets, wedges, rods, cylin- 
 ders, tubes, pistons, valves, buckets, 
 floats, weights, beams, racks, chains, 
 clutches, winches, etc. (See also 
 Vols. 114 and 115, for popular 
 elucidation, in the ' Rudimentary 
 Series.') 
 
 The power of engines, as distin- 
 guished from machines, depends 
 up6n the nature of the material 
 
 268* 
 
MAC 
 
 MADDER. 
 
 MAG 
 
 from which their power is gathered. 
 The mere mechanical effect of every 
 piece of machinery is calculable 
 upon its combinations of certain 
 elementary forms, commonly term- 
 ed the mechanical powers, with 
 deductions from the effect of these 
 for friction between the parts, for 
 rigidity of parts which are theore- 
 tically supposed to be perfectly 
 flexible, and for the elasticity of 
 parts which are supposed to be 
 perfectly rigid. 
 
 The mechanical powers, some- 
 times described as six in number, 
 viz. the lever, the wheel and axle, 
 the pulley, the inclined plane, the 
 wedge, and the screw, are reduci- 
 ble to two only, viz. the lever and 
 the inclined plane, in each of which 
 the effect produced is just as many 
 times greater than the power em- 
 ployed, as the space through which 
 the power moves is greater than 
 the space through which the effect 
 is continued. Thus, if with a lever 
 a weight be raised ten times greater 
 than the weight or power by which 
 it is raised, this weight or power 
 will have to move through ten 
 times as much space as the height 
 through which the greater weight 
 is raised. 
 
 Propriety of form in the detail 
 of machinery depends upon two 
 circumstances. The first is, that 
 the parts subject to wear and tear, 
 and influenced by strains, should be 
 capable of motion or adjustment : 
 the second, that every portion 
 should be equally strong, and pre- 
 sent to the eye a uniform figure, 
 or one that is consistent with its 
 degree of action : theory, practice, 
 and taste, all must combine to 
 produce such. A great extent 
 of beauty is attainable in all the 
 details, but mathematical reasons 
 cannot be given why a certain 
 arrangement of lines should be 
 preferable to another, provided 
 they are equally strong. Truth 
 does not strike us without the as- 
 sistance of custom ; but so great is 
 
 the force of custom, that unassisted 
 by truth it has worked the greatest 
 miracles ; and it certainly must be 
 this universal Mentor which gives 
 us the power to choose between 
 forms. 
 
 MaceUum, a market-place for all kinds 
 of provisions. 
 
 Maceria, a rough wall. 
 
 Machicolations, openings formed for 
 the purpose of defence at the top 
 of castles and fortifications, by set- 
 ting the parapet out on corbels, so 
 as to project beyond the face of the 
 wall. 
 
 Madder carmine, or Field's carmine, 
 is, as its name expresses, prepared 
 from madder. It differs from the 
 rose lakes of madder principally in 
 texture, and in the greater rich- 
 ness, depth, and transparency of its 
 colour, which is of various hues, 
 from rose-colour to crimson. 
 
 Madder orange, or Orange lake, is a 
 madder lake of an orange hue, va- 
 rying from yellow to rose-colour 
 and brown. 
 
 Madder purple, Purple rubiate, or 
 Field's purple, is a very rich and 
 deep carmine, prepared from mad- 
 der. Though not a brilliant pur- 
 ple, its richness, durability, trans- 
 parency, and superiority of colour, 
 have given it the preference to the 
 purple of gold purple, and to burnt 
 carmine. 
 
 Madder yellow is a preparation from 
 the madder-root. The best is of a 
 bright colour, resembling Indian 
 yellow, but more powerful and 
 transparent, though hardly equal 
 to it in durability of hue ; metallic, 
 terrene, and alkaline substances 
 acting on and reddening it as they 
 do gamboge : even alone, it has by 
 time a natural tendency to change 
 in appearance. 
 
 Maeniana, seats in the upper porticoes 
 of the Roman forum, from whence 
 spectators witnessed the combats 
 of gladiators. 
 
 Magnase black is the best of all 
 blacks for drying in oil without 
 addition, or preparation of the oil : 
 
MAH 
 
 MANNER. 
 
 MAN 
 
 it is a colour of vast body and 
 tingeing power. 
 
 Mahogany is a native of the West 
 Indies and the country round the 
 Bay of Honduras. It is said to be 
 of rapid growth, and so large that 
 its trunk often exceeds 40 feet in 
 length and 6 feet in diameter. 
 Spanish mahogany is imported from 
 Cuba, Jamaica, Hispaniola, St. Do- 
 mingo, and some other of the West 
 India Islands, in logs from about 
 20 to 26 inches square and 10 feet 
 long. It is close-grained and hard. 
 There is also African mahogany. 
 All the species are used for many 
 purposes, more particularly for su- 
 perior household furniture. 
 
 Main links, the links in the parallel 
 motion which connect the piston- 
 rod to the beam of a steam-engine. 
 
 Mainmast of a ship, a long piece of 
 round timber, upright in the waist 
 or middle of a ship. 
 
 Malleable, in metallurgy, capable of 
 being spread by heating or by 
 rolling, a distinguishing character 
 of metals, but more especially of 
 gold. When flattened, it is said to 
 be laminable ; when drawn as wire, 
 ductile. 
 
 Manacaybo is a furniture wood of 
 moderate size, hard, as good as ma- 
 hogany, and in appearance between 
 that and tulip- wood. 
 
 Manchineel, a large tree of the West 
 Indies and South America : it 
 possesses the general character of 
 mahogany, but has a poisonous and 
 unwholesome sap. 
 
 Mandril, the spindle which carries 
 the centre-chuck of a lathe, and 
 communicates motion to the metal 
 to be turned : in small lathes it is 
 driven by a pulley. 
 
 Mandril-frame, the head-stocks or 
 frame bolted to the end of a lathe- 
 bed, for the purpose of supporting 
 the mandril. 
 
 Mangrove, an aquatic tree, straight- 
 grained, hard, and elastic : much 
 used for ship-building. 
 
 Man-hole, an opening in the top of a 
 boiler, used as an entrance when 
 
 270* 
 
 the boiler requires cleaning : it is 
 covered by a strong plate bolted to 
 the boiler plating, so as to be steam- 
 tight. 
 
 Man-hole cover, a strong plate of iron, 
 bolted over the man-hole so as to 
 be removable when required. 
 
 Manipulation, in mining, the manner 
 of digging silver or other metals ; 
 a term now generally applied to 
 the means by which materials or 
 effects are produced. 
 
 Manner is that habitude which paint- 
 ers have acquired, not only in the 
 management of the pencil, but also 
 in the principal parts of painting, 
 invention, design, and colouring. 
 It is by the manner in painting that 
 a picture is judged to be by the 
 hand of Titian, Tintoret, Guido, the 
 Caracci, and others. Some masters 
 have had a variety in their manners 
 at different periods of life, and 
 others have so constantly adhered 
 to one manner, that those who have 
 seen even a few of them will imme- 
 diately know them, and judge of 
 them without any risk of a mistake. 
 The variety observable among ar- 
 tists in their manner and taste 
 arises from the practice of the dif- 
 ferent schools in which they have 
 received their instructions, or of the 
 artists under whom they have stu- 
 died. Yet there are many instances 
 of great artists who have divested 
 themselves of that early partiality 
 to a peculiar manner, and have 
 altered it so effectually as to fix on 
 one abundantly more refined and 
 better adapted to their peculiar 
 genius, by which means they have 
 arrived at excellence. Thus, for 
 instance, Raphael proceeded, and 
 acquired a much more elevated 
 manner after he had quitted the 
 school of Perugino. 
 
 Mannerist, a term applicable to a 
 painter whose pictures have no re- 
 semblance to the beautiful varieties 
 of nature,but discover an unpleasing 
 and tasteless sameness. 
 
 Manometer, an instrument intended 
 to measure the rarefaction and con- 
 
MAN 
 
 MASONRY. 
 
 MAS 
 
 densation of elastic fluids in confined 
 circumstances, whether occasioned 
 by variation of temperature or by 
 actual destruction, or generation of 
 portions of elastic fluids. 
 
 Mansard roof, of French origin, from 
 the name of the inventor ; a curb 
 roof. 
 
 Manse, a parsonage-house. 
 
 Mansum capitale, the chief mansion, 
 manor-house, or court of a lord. 
 
 Mantelpiece, a beam across the open- 
 ing of a fire-place, serving as a 
 lintel or bressummer to support 
 the masonry above, which is called 
 the chimney-breast. 
 
 Maple-wood is considered to be allied 
 to the sycamore or the plane-tree ; 
 its colour is pale : much used for 
 picture-frames and Tunbridge ware. 
 
 Marble, a kind of stone found in great 
 masses, and dug out of pits or 
 quarries. 
 
 Marcus, a large iron-headed hammer. 
 
 Margin, or Lock-rail, the flat part of 
 the stile and rail of framed work. 
 
 Marine engine, a steam-engine to pro- 
 pel a ship. There are various kinds 
 of them, the beam, direct-acting, 
 oscillating, trunk, high-pressure 
 as used in our new gun-boats, etc. 
 (See Murray's work, Vols. 80 and 
 81, in the 'Rudimentary Series.') 
 
 Market. The market or forum in the 
 cities of antiquity was different 
 from the market in our English 
 towns, where flesh meat, merchan- 
 dise, etc., are usually sold. The 
 Apostle Paul disputed with philo- 
 sophers in the market at Athens : 
 this and other evidences prove it 
 to have been also a place of dispu- 
 tation and public resort. 
 
 Marline, a small line used for winding 
 round ropes and cables. 
 
 Marmoration, a building with marble. 
 
 Marone is of a class of impure colours, 
 composed of black and red, black 
 and purple, or black and russet 
 pigments, or with black and any 
 other denomination of pigments in 
 which red predominates. 
 
 Marone lake is a preparation of mad- 
 der, of great depth, transparency, 
 
 271* 
 
 and durability of colour : it works 
 well in water, glazes and dries in 
 oil, and is in all respects a good 
 pigment : its hues are easily given 
 with other pigments, but it is not 
 much used. 
 
 Marquetry, chequered or inlaid work ; 
 work inlaid with variegation, a sort 
 of veneering, representing flowers, 
 birds, and other figures. 
 
 Masaccio, of the Florentine School, a 
 very eminent painter, and distin- 
 guished for his foreshortenings and 
 colouring. He died in 1443. 
 
 Masonry. The early Roman archi- 
 tecture, both in public and private 
 buildings, was of far more durable 
 materials, and of more accurate 
 masonry than such as was executed 
 in the decline of the Empire. It 
 began to be uncemented blocks of 
 stone, passed into the reticular work 
 of the Republic, thence into the 
 travertine, and descended into the 
 mixture of tufo, and brick, and 
 stucco facing. 
 
 Marble is polished by being first 
 rubbed with grit-stone, afterwards 
 with pumice-stone, and lastly with 
 emery or calcined tin. Marbles, 
 with regard to their contexture and 
 variegation of colour, are almost in- 
 finite : some are black, some white, 
 and some of a dove colour : the best 
 kind of white marble is called 
 statuary, which, when cut into thin 
 slices, becomes almost transparent, 
 which property the other kinds do 
 not possess. Other species of mar- 
 ble are streaked with clouds and 
 veins. The texture of marble is not 
 altogether understood, even by the 
 best workmen ; but they generally 
 know upon sight whether it will 
 receive a polish or not. Some mar- 
 bles are easily wrought, some are 
 very hard, other kinds resist the 
 tools altogether. Artificial marble, 
 or Scagliola, is real marble pulver- 
 ized and mixed with plaster, and is 
 used in columns, basso-rilievos, and 
 other ornaments. 
 
 The chief kind of stone used in 
 London is Portland stone, which 
 
MAS 
 
 MATTER. 
 
 MAX 
 
 comes from the island of Portland, 
 in Dorsetshire ; it is used for Build- 
 ings in general, as strings, window- 
 sills, balusters, steps, copings, etc., 
 but under great weight or pressure 
 it is apt to splinter, or flush at the 
 joints. When it is recently quar- 
 ried, it is soft and works easily, but 
 acquires great hardness in course 
 of time. St. Paul's cathedral and 
 Westminster bridge are construct- 
 ed of Portland stone. 
 
 Purbeck stone comes from an 
 island of the same name, also in 
 Dorsetshire, and is mostly employed 
 in rough work, as steps and paving. 
 
 Yorkshire stone is also used 
 where strength and durability are 
 requisites, as in paving and coping. 
 
 Ryegate stone is used for hearths, 
 slabs, and covings. 
 
 Mortar is used by masons in ce- 
 menting their works. (See Brick- 
 laying, Cements, Mortars, etc.) In 
 setting marble or fine work, plaster 
 of Paris is used, and in water-works, 
 tarras is employed. 
 
 Tarras is a coarse mortar, durable 
 in water and in most situations. 
 Dutch tarras is made of a soft rock- 
 stone, found near Cologne, on the 
 Rhine. It is burnt like lime, and 
 reduced to powder by mills, from 
 thence carried to Holland, whence 
 it has acquired the name of Dutch 
 tarras. It is very dear, on account 
 of the great demand for it in the 
 construction of aquatic works. 
 
 An artificial tarras is formed of 
 two parts of lime and one of plaster 
 of Paris : another sort consists of 
 one part of lime and two parts of 
 well-sifted coal ashes. 
 Masques, grotesque faces used to fill 
 vacant places, on friezes, panels of 
 doors, keys of arches, etc. 
 Mast carlings, in ship-building, large 
 timbers at the side of the mast 
 rooms that are left deep enough to 
 receive the cross-chocks. 
 Mastic, a cement used for the plaster- 
 ing of walls. 
 
 Mastic varnish is easily prepared by 
 digesting in a bottle, during a few 
 
 hours, in a warm place, one part of 
 dry picked resin with two parts or 
 more of the oil of turpentine. 
 
 Materiatio, according to Vitruvius, 
 the timber-work of a roof. 
 
 Materiation, felling of timber for 
 building. 
 
 Mathematics, a science which teaches 
 to number and measure whatever 
 is capable of it, comprised under 
 lines, numbers, superficies,or solids. 
 
 Matter and Motion. Quantities of 
 matter in all bodies are in the com- 
 pound ratio of their magnitude and 
 densities ; for if the magnitudes are 
 equal, the quantities of matter will 
 be as the densities ; and if the den- 
 sities are equal, the quantities of 
 matter will be as the magnitudes : 
 therefore, the quantities of matter 
 are universally in the compound 
 ratio of both. 
 
 Matter. 1. Matter in general, ma- 
 teriality, corporeity, corporality,ma- 
 terialness, substantiality, physical 
 condition. 2. Inorganic matter, 
 solid matter, density, solidity, in- 
 compressibility, cohesion, fluid 
 matter, liquidity, liquidness,vapori- 
 zation, specific fluids, fluids in mo- 
 tion, organic matter. 
 
 Maul-stick, a painter's stick, upon 
 which he leans his hand when at 
 work. 
 
 Mauritius, of London 1086-1108 
 built the cathedral of Old Saint 
 Paul's. 
 
 Mausoleum, a pompous funereal mo- 
 nument, a costly sepulchre. 
 
 Maximum and Minimum. The ex- 
 tremes of temperature are no less 
 important to the meteorologist than 
 interesting to the general observer. 
 They are obtained by the self-re- 
 gistering thermometer. The first 
 instrument of this kind was sug- 
 gested by John Bernouilly. Several 
 forms of thermometers were com- 
 municated to the Royal Society by 
 Lord Charles Cavendish. The next 
 in point of time were the contri- 
 vances of Fitzgerald and Crighton. 
 Six, Rutherford, Keith, Blackadder, 
 and Dr. Trail, greatly added to the 
 
 272* 
 
MEA 
 
 MEASUREMENT OF EARTHWORK. 
 
 MEA 
 
 stock of self-registering thermo- 
 meters. There are two kinds in 
 general use ; Mr. Six's, which is 
 placed vertically, and Dr. Ruther- 
 ford's, which is suspended horizon- 
 tally. The latter is preferable on 
 land, and, from its simplicity, has 
 to a certain extent superseded the 
 former. 
 
 Mear, thirty-two yards of ground in 
 a vein of ore. 
 
 Measurement of earthwork. There 
 are many works and tables pub- 
 lished to facilitate the admeasure- 
 
 ment of earth-work, which may be 
 reduced in practice to the follow- 
 ing geometrical forms, in one or 
 more chains in length, as the case 
 may be. The two chains marked 
 B and c in the section will reduce I 
 to the forms in the diagrams that 
 follow. The dotted lines, fig. 1, 
 show the section at the largest end, 
 next to B in the section ; and the 
 dotted line, fig. 2, shows the sec- 
 tion at the smallest end, next to A 
 in the section. 
 
 The bottom piece, c, being re- 
 
 Fig, i, 
 
 duced to a parallel throughout, is 
 measured by multiplying the area of 
 Slopes 2 to 1 . 
 
 Fig. 2. 
 
 Slopes '2 to 1. 
 
 the end by the length : the two 
 273* 
 
 banks being equal, it will measure 
 thus : 15' 0" x 57' 0" x 132' 0". 
 
 The piece B, the middle or wedge 
 piece, being parallel horizontally 
 only, is measured by taking one- 
 half the vertical height : thus, 
 3'6"x37' 0"x 132' 0". 
 
 The two pieces B B form the two 
 halves of a right-angled pyramid, 
 and are measured by multiplying 
 the area of the end by one-third 
 the height: therefore 7' 0" x 14'0", 
 the slope being 2 to 1, is equal to 
 98' 0" ; the area of the two bases 
 then, l / 0"x98'0 // x44'0' / , gives 
 the cube quantity in the two. 
 Measurement of shipping for tonnage 
 (called the 'new measurement') 
 was regulated in the 5th and 6th 
 of George IV. By this Act certain 
 rules were established for ascer- 
 taining the tonnage of ships, as 
 well on shore as afloat, and of ves- 
 sels propelled by steam ; and the 
 account of such tonnage, whenever 
 the same shall have been ascer- 
 tained according to the rules herein 
 prescribed (except in the case of 
 ships admeasured afloat), it is en- 
 acted, shall be deemed the tonnage 
 of such ships, and shall be repeated 
 
MEA 
 
 MEASUREMENT OF SHIPPING. 
 
 MEA 
 
 in every subsequent registry, of 
 such ships, unless any alteration 
 shall have been made in their form 
 and burthen, or unless it be disco- 
 vered that the tonnage had been 
 erroneously computed: and it is 
 considered that the capacity of a 
 ship is the fairest standard by which 
 to regulate its tonnage ; that inter- 
 nal measurements will afford the 
 most accurate and convenient me- 
 thod of ascertaining that capacity, 
 and that the adoption of such a 
 mode of admeasurement will tend 
 to the interest of the ship-builder 
 and the owner. 
 
 It was enacted that the tonnage 
 of every ship or vessel required by 
 law to be registered shall, previous 
 to her being registered, be mea- 
 sured and ascertained while her 
 hold is clear, and according to the 
 following rule : Divide the length 
 of the upper deck between the 
 after-part of the stem and the fore- 
 part of the stern-post into six equal 
 parts. Depths : At the foremost, 
 the middle, and the aftermost of 
 those points of division, measure 
 in feet and decimal parts of a foot 
 the depths from the under side of 
 the upper deck to the ceiling at 
 the limber strake. In the case of a 
 break in the upper deck, the depths 
 are to be measured from a line 
 stretched in a continuation of the 
 deck. Breadths: Divide each of 
 those three depths into five equal 
 parts, and measure the inside 
 breadths at the following points : 
 at one-fifth and at four-fifths from 
 the upper deck of the foremost and 
 aftermost depths, and at two-fifths 
 and four-fifths from the upper deck 
 of the midship depth. Length : 
 At half the midship depth measure 
 the length of the vessel from the 
 after-part of the stem to the fore- 
 part of the stern-post, then to 
 twice the midship depth add the 
 foremost and the aftermost depths 
 for the sum of the depths ; add to- 
 gether the upper and lower breadths 
 at the foremost division, three times 
 
 the upper breadth and the lower 
 breadth at the midship division, 
 and the upper and twice the lower 
 breadth at the after division, for 
 the sum of the breadths ; then mul- 
 tiply the sum of the depths by the 
 sum of the breadths, and this pro- 
 duct by the length, and divide the 
 final product by three thousand five 
 hundred, which will give the num- 
 ber of tons for register. If the 
 vessel have a poop or half-deck, or 
 a break in the upper-deck, measure 
 the inside mean length, breadth, 
 and height of such part thereof as 
 may be included within the bulk- 
 head ; multiply these three mea- 
 surements together, and dividing 
 the product by 92-4, the quotient 
 will be the number of tons to be 
 added to the result as above found. 
 In order to ascertain the tonnage 
 of open vessels, the depths are to 
 be measured from the upper edge 
 of the upper strake. 
 
 To ascertain the tonnage of steam 
 vessels, it was also further enacted, 
 that in each of the several rules 
 prescribed, when applied for the 
 purpose of ascertaining the tonnage 
 of any ship or vessel propelled by 
 steam, the tonnage due to the cu- 
 bical contents of the engine-room 
 shall be deducted from the total 
 tonnage of the vessel as determined 
 by the rules, and the remainder 
 shall be deemed the true register 
 tonnage of the said ship or vessel. 
 The tonnage due to the cubical 
 contents of the engine-room shall 
 be determined in the follo\ving 
 manner: measure the inside length 
 of the engine-room in feet and de- 
 cimal parts of a foot from the fore- 
 most to the aftermost bulk-head, 
 then multiply the said length by 
 the depth of the ship or vessel at 
 the midship division, as aforesaid, 
 and the product by the inside 
 breadth at the same division at 
 two-fifths of the depth from the 
 deck taken as aforesaid, and divide 
 the last product by 92-4, and the 
 quotient is deemed the tonnage 
 
tEA 
 
 MECHANICS. 
 
 MEC 
 
 due to the cubical contents of the 
 engine-room. 
 
 feasurement of standing timber. 
 Measure from the tree ten, twenty, 
 thirty, etc., feet, and then plant the 
 theodolite level : direct the tele- 
 scope to the bottom of the tree, 
 and observe the degree and tenth 
 of depression ; and to the top of 
 the tree, the degree and tenth of 
 elevation. When the timber has 
 been previously felled, it is custom- 
 ary, in measuring, to girt a string 
 round the middle of the tree, and 
 fold it twice, which will give the 
 fourth part of the girt, and which 
 is considered the true side of the 
 square ; then the length is mea- 
 sured from the butt-end of the 
 tree, so far up as the tree will hold 
 half a foot girt, or, more properly 
 speaking, quarter-girt ; that is, the 
 line six inches when twice folded. 
 Various tables are published, to 
 assist the timber-measurer in the 
 performance of his duty. All tim- 
 ber is bought and sold by the load, 
 and a load is estimated at forty 
 feet of unhewn or rough timber, 
 and fifty feet of hewn timber, which 
 is supposed to weigh one ton, or 
 twenty hundredweight. 
 Measurement of base lines, the whole 
 of the operations connected with 
 the execution of a trigonometri- 
 cal survey of a country, require 
 the most scrupulous care, and a 
 large amount of skill, that the 
 many errors which are inseparable 
 from the instruments that are used, 
 and the several processes that 
 must be followed, may be dimi- 
 nished as far as practicable, and the 
 necessary precautions taken, where- 
 by the corrections to the observa- 
 tions and measurements may be 
 applied, so as to produce the 
 greatest amount of accuracy with 
 the least alteration of the given 
 elements. 
 
 Of these processes, the primary 
 is that which consists in the accu- 
 rate measurement of the distance 
 between two stations A and B, 
 
 275* 
 
 designed to serve as the base, to 
 which the whole extent of country 
 intended to be surveyed, is to be 
 referred. 
 
 This measurement is generally 
 expressed in terms of the standard 
 of length of the country in which 
 the operation is carried on, although 
 the actual measurements may in 
 the first instance have been given 
 in terms of some other standard. 
 It is not, however, requisite that 
 the measurement of the base should 
 precede the angular observations, 
 and although generally it is first 
 undertaken, it can be equally well 
 done when every other portion of 
 the work has been completed. 
 
 The selection of a site for the 
 base is a matter of considerable 
 importance ; a level plain or ground 
 with as little undulation as possible, 
 and a distance varying from five to 
 eight miles is to be preferred ; the 
 extremities of the base being suf- 
 ficiently elevated (either from the 
 nature of the ground or by the use 
 of an artificial stage) above the 
 surrounding country to allow of 
 other stations C and D being seen, 
 and these should be so situated as 
 to form well-conditioned triangles 
 with the base A B, inasmuch as 
 small errors in the measurement of 
 very acute angles would produce 
 large errors in the lengths of the 
 sides deduced from them. 
 
 It must not, however, be in- 
 ferred, that a perfect level is ab- 
 solutely requisite for the measure- 
 ment of a base line. That situated 
 on Salisbury Plain has now been 
 twice measured, although there is 
 a difference of level of 428 feet 
 between its two extremities. 
 
 Mechanical powers are contrivances 
 by which we are enabled to sustain 
 a great weight or overcome a great 
 resistance by a small force. (See 
 Machinery.) 
 
 Mechanics, that branch of practical 
 science which considers the laws of 
 equilibrium and the motion of solid 
 bodies ; the forces by which bodies, 
 
MEC 
 
 MECHANICS. 
 
 MEN 
 
 whether animate or inanimate, may 
 be made to act upon one another ; 
 and the means by which these 
 forces may be increased so as to 
 overcome those which are more 
 powerful. The term Mechanics was 
 originally applied to the doctrine 
 of equilibrium. It is now, how- 
 ever, extended to the motion and 
 equilibrium of all bodies, whether 
 solid, fluid, or aeriform. The com- 
 plete arrangement of mechanics is 
 now made to embrace, besides, the 
 pressure and tension of cords, the 
 equilibrated polygon, the catenary 
 curve, suspension bridges, the equi- 
 librium of arches and the stability 
 of their piers, the construction of 
 oblique arches, the equilibrium of 
 domes and vaults with revetments, 
 the strength of materials, whether 
 they he of wood or iron, dyna- 
 mics (or the science of moving 
 bodies), with hydrostatics, pneuma- 
 tics, and hydraulics. 
 
 Definitions are explanations of 
 terms by means of other terras, the 
 meanings of which are understood : 
 we shall assume that the term 
 weight will be accepted without 
 explanation. 
 
 DEF. Everything which has 
 weight is called matter, and a 
 body is a portion of matter limited 
 in every direction. 
 
 DEF. Space is that which con- 
 tains or is capable of containing 
 matter, and is continuous and in- 
 finite. 
 
 DEF. A body is said to be ab- 
 solutely at rest as long as it re- 
 mains in the same position in space; 
 and to he absolutely in motion while 
 it is in the act of changing its 
 position in space. 
 
 DEF. A body is said to be rela- 
 tively at rest as long as it remains 
 in the same position with respect 
 to some other body with regard to 
 which its state is to be considered; 
 and to be relatively in motion while 
 it is in the act of changing its 
 position with respect to this body. 
 
 The states of rest and motion 
 
 276* 
 
 which we have generally to con- 
 sider are relative and not absolute. 
 Thus we have to consider the mo- 
 tion of a locomotive relatively to 
 the surface of the earth, and not 
 the absolute motion made up of 
 this and that of the earth itself, 
 and the motions of the parts of the 
 engine relatively to the frame of 
 the locomotive without regard to 
 the motion of the whole along the 
 road. 
 
 DEF. Force is any cause which 
 produces or tends to produce a 
 change in the state of rest or mo- 
 tion of a body. 
 
 Forces are measured by the 
 effects which they produce, and 
 hence in considering effects of dif- 
 ferent kinds different measures of 
 forces may be introduced. 
 
 When a body is acted upon by 
 only a single force, a change in its 
 state of rest or motion will always 
 take place; but two or more forces 
 acting on a body at the same time 
 may counteract each other's effects, 
 so that the body may be in exactly 
 the same state as though these 
 forces were not acting upon it. 
 
 DEF. Two or more forces which 
 counteract each other's effects are 
 said to be in equilibrium. (From 
 the Course of Mathematics for the 
 use of Students at the Royal Mili- 
 tary Academy, Woolwich, vol. iii.) 
 
 Medallion, in architecture, any cir- 
 cular tablet on which figures are 
 embossed ; busts, etc. 
 
 Mediaeval, relating to the middle ages. 
 
 Member, a moulding ; either as a 
 cornice of five members, or a base 
 of three members, and applied to 
 the subordinate parts of a building. 
 
 Mensuration is the application of the 
 science of arithmetic to geometry, 
 by which we are enabled to dis- 
 cover the magnitudeanddimensions 
 of any geometrical figures, whether 
 solid or superficial. To enable us 
 to express this magnitude in deter- 
 minate terms, it is necessary to 
 assume some magnitude of the 
 same kind as the unit, and then, by 
 
MER 
 
 MERE, HAARLEMMER. 
 
 MER 
 
 stating how many times the given 
 magnitude contains that unit, we 
 obtain its measure. 
 
 The different species of magni- 
 tude which have most frequently 
 to be determined are distinguish- 
 able into six kinds, viz. 1. Length. 
 2. Surface. 3. Solidity, or ca- 
 pacity. 4. Force of gravity, com- 
 monly called weight. 5. Angles. 
 6. Time. 
 
 Mere, or Meer, a name frequently 
 given, in England and the Nether- 
 lands, to inland lakes or sheets of 
 fresh water, such as Windermere, 
 Whittleseamere, Ugg-mere, So- 
 ham-mere, in England, and the 
 Egmonder meer, Purmer meer, and 
 Haarlemmer meer, etc., in the Ne- 
 therlands. The term is most fre- 
 quently used in the latter country, 
 where, prior to 1440, there were 
 more than 150 meers, of which 85 
 occupied an area of 177,832 acres, 
 since drained and reclaimed, in the 
 provinces of North and South Hol- 
 land ; and where also the Haarlem- 
 mer meer, covering an area of 
 45,230 acres, is now in course of 
 drainage. 
 
 As the meers, in fen-lands, serve 
 'as reservoirs to hold a portion of 
 the surplus rain-water falling on 
 the district of which they form a 
 part, their being dyked off and 
 drained, where of considerable ex- 
 tent, has most important effects on 
 the neighbouring lands, by con- 
 tracting the area of the rese/voir 
 or catch-water basin of the district. 
 But as these drainages generally 
 oblige improvements in the out- 
 falls, their result is mostly benefi- 
 cial to the other lands. 
 
 The beds of the Dutch meers 
 are from 10 to 20 feet below the 
 level of the lowest point of the 
 natural outfall in their districts ; 
 consequently they are always 
 drained by mechanical means. 
 Windmills have been employed *to 
 dra'in the land, in the Netherlands, 
 from time immemorial; but the 
 drainage of the meers was not com- 
 
 277 
 
 menced until 1440, about which 
 period windmills and draining 
 machinery were considerably im- 
 proved; and as late as 1840, wind- 
 mills for draining purposes conti- 
 nued in favour with the Dutch 
 engineers, in preference to steam 
 engines ; and at that date, 12,000 
 windmills were employed to drain 
 the polders, in the Netherlands, 
 and only five small steam-engines, 
 the largest not exceeding 30-horse 
 power : the average consumption 
 of fuel was 20 Ibs. of coal per horse 
 power per hour. 
 
 In the English fens, steam had 
 in a great measure superseded wind- 
 mills for drainage purposes ; but 
 the consumption of fuel was nearly 
 as great as in the Dutch engines. 
 
 In 1839, the Dutch States-Ge- 
 neral decreed the drainage of the 
 Haarlemmer meer, and voted eight 
 millions of florins for that purpose, 
 to which two millions more were 
 subsequently added, making the 
 total sum of 834,000. 
 
 The Haarlemmer meer forms 
 part of the great drainage district 
 of Rhynland, which has an area of 
 305,014 English acres : prior to 
 1848, this area was occupied by 
 56,609 acres of meers and water- 
 courses, nearly all in communica- 
 tion with each other, forming what 
 is called the boezem, or catch-water 
 basin of the district ; the surface of 
 the water being maintained at the 
 lowest level of natural sluiceage, 
 by sluices at Katwyk into the North 
 Sea, and at Sparndam and Halfweg 
 into the Y, or the southern end of 
 the Zuyder Zee. 
 
 Above the boezem are 75,357 
 acres drained into it by natural 
 level ; and at depths from 2 feet 6 
 inches to 4 feet below it are 170 
 polders covering an area of 135,850 
 acres; and 37,198 acres, divided 
 into 28 polders which were for- 
 merly meers. but are now drained, 
 and whose beds are on an average 
 14 ft. below the level of the boezem. 
 
 The surplus rain and infiltration 
 
MER 
 
 MERE, HAARLEMMER. 
 
 MER 
 
 waters from the 173,048 acres of 
 polder-land are lifted into the b*oe- 
 zem by the united action of 261 
 large windmills, with an average 
 force of 1500-horse power. 
 
 The drainage of the Haarlemmer 
 meer, which forms part of the boe- 
 zem or basin, will deduct 45,230 
 acres from its area, and reduce it 
 to 11,379 acres, or th part of its 
 former size : whilst the land surface 
 drained into it will be increased 
 from 229,657 to 293,735 acres. 
 
 The average level of the boezem 
 is 10 inches below the ordinary 
 low water, and 27 inches below 
 high-water mark in the Y or Zuy- 
 der Zee ; and 7 inches above low 
 water, and 57 inches below ordi- 
 nary high water, in the North Sea. 
 
 The bed of the Haarlem Lake is 
 14 feet below the winter level of 
 the boezem; and when drained, 
 the maximum lift will be 16 feet 
 6 inches to 17 feet, according to 
 the state of the wind, which raises 
 or depresses the surface of the wa- 
 ter in the canals very considerably. 
 
 The water contents of the Haar- 
 lemmer meer to be pumped out, 
 including the additional quantity 
 arising from the surplus rain and 
 infiltration during the draining, are 
 estimated at 800,000,000 cubic 
 metres or tons. 
 
 The greatest quantity of monthly 
 drainage when the meer is pumped 
 out is estimated at 36,000,000 tons, 
 and the annual average surplus of 
 rain- water, etc., at 54,000,000 tons 
 to be lifted, on an average, 16 feet. 
 
 The Dutch engineers were gene- 
 rally in favour of windmills, or a 
 combination of windmills and 
 steam-engines, for pumping out 
 the meer; but in 1841, the late 
 king, William II., by the advice of 
 a commission, decreed that steam- 
 engines only should be employed 
 for the purpose; and in 1842, at 
 the suggestion of two English en- 
 gineers, Mr. Arthur Dean and Mr. 
 Joseph Gibbs, it was determined 
 to erect, and they were directed to 
 
 278 
 
 prepare the designs for, three 
 steam-engines upon the high pres- 
 sure, expansive, condensing prin- 
 ciple, of the ordinary force of 350- 
 horse power each, but capable of 
 being worked on emergencies up 
 to 500-horse power. 
 
 The consumption of fuel was 
 limited to 2 Ibs. of coal per horse 
 power per hour. 
 
 The three engines were named 
 the ' Leeghwater,' ' Cruquius,' and 
 ' Lynden,' after three celebrated 
 men who had at different periods 
 proposed plans for draining the 
 Haarlemmer meer. 
 
 The ' Leeghwater ' was the first 
 erected, to work eleven pumps of 
 63 inches diameter, with 10-feet 
 stroke in pumps and steam cylin- 
 ders ; and the ' Cruquius ' and ' Lyn- 
 den ' were afterwards constructed, 
 to work eight pumps each, of 73 in. 
 diameter, and with 10-feet stroke ; 
 each engine is calculated to lift 66 
 cubic metres of water per stroke. 
 
 The accompanying sketch is a 
 representation of the interior of 
 the ' Lynden ' engine and engine- 
 house, on the upper floor : the 
 ' Cruquius ' is on the same model ; 
 but the ' Leeghwater ' has the inner 
 ends of its eleven pump-beams ar- 
 ranged under the great cross-head, 
 instead of over it. 
 
 Each engine has two steam cy- 
 linders, placed concentrically, the 
 one within the other, the outer of 
 12 feet diameter, and the inner 
 one of 7 feet diameter : both are 
 secured to one bottom, and covered 
 by one cover, but the inner cylin- 
 der does not touch the cover 
 within 1-g- inch : there are two 
 pistons, 26 inches deep, the com- 
 partments of which are fitted with 
 cast-iron plates : the outer piston 
 is annular, and has a packing on 
 both sides : beneath this annular 
 piston a constant vacuum is main- 
 tained when working : the two pis- 
 tons are connected by five piston- 
 rods, as shown in the sketch, to a 
 great cross-head or cap, the whole 
 
MER 
 
 MERE, HAARLEMMER. 
 
 MER 
 
 mass weighing about 85 tons, and 
 by eight connecting-rods the cap 
 pistons are suspended from the in- 
 
 ner ends of eight cast-iron balance- 
 beams to the outer ends of which 
 are hung the eight pump-pistons; 
 
 279 
 
 N 2 
 
MER 
 
 MERE, HAARLEMMER. 
 
 MER 
 
 the action of the engines is therefore 
 very simple : the steam being ap- 
 plied under the inner piston, lifts 
 both the pistons, the great cross- 
 head, and inner ends of pump ba- 
 lance-beams simultaneously, and the 
 pump-pistons descend at the same 
 time : by an hydraulic apparatus 
 attached to the great cross-head, 
 the dead weight of the pistons, etc., 
 is arrested at the point to which it 
 has been thrown up by the steam, 
 and time is given for the valves of 
 the pump-pistons to close before 
 the down-stroke of the steam-pis- 
 tons is made ; then, the equili- 
 brium-valve being opened, the hy- 
 draulic apparatus is liberated at 
 the same moment, and the steam 
 passing from beneath the small pis- 
 ton, above both pistons, the pres- 
 sure on both sides of the small 
 one is equalized, whilst nearly two- 
 thirds of the steam acts upon the 
 annular piston against a vacuum, 
 and in aid of the dead weight 
 helps to make the down-stroke in 
 the steam-cylinder, and the up- 
 stroke in the pumps. The use of 
 the two cylinders enables the en- 
 gine-man, by judiciously altering 
 the expansion in the small cylinder, 
 to command his work at all times, 
 without stopping the engine to 
 take out, or put in, dead weight, as 
 would be necessary for a single- 
 acting one-cylinder engine, where 
 dead weight only is used for lifting 
 the water. It has frequently oc- 
 curred that the load of an engine 
 has been added to or diminished 
 by 10 or 12 tons in the course of 
 half an hour, by the action of gales 
 of wind on the surface of the meer 
 and boezem. Each engine has two 
 air-pumps of 40 in. diameter, and 
 5-feet stroke. The steam is cut off 
 in the small cylinder at from one- 
 fourth to two-thirds of the stroke, 
 according to the load ; and after 
 expanding through the remainder 
 of the stroke, it is still further ex- 
 panded in the large cylinder. 
 The anticipated economy in con- 
 
 sumption of fuel has been realized : 
 when working with the net power 
 of 350 horses, the average consump- 
 tion is 2\ Ibs. of best Welsh coals, 
 or 75 millions duty with 94 Ibs. of 
 coal ; and on a late trial, the ' Cru- 
 quius ' and ' Lynden ' engines were 
 found to do a duty of 87 millions. 
 The whole cost of machinery, 
 buildings, coals, and wages, to 
 pump out the lake, will not exceed 
 150,000, whereas, by wind it 
 would have cost 308,000, being 
 a saving of 158,000; and there 
 will also be a further economy upon 
 the works in the bed of the lake, 
 amounting to % 40,000 more, so 
 that the total saving by steam over 
 wind will be 200,000, and three 
 years' time. 
 
 To compensate the district of 
 Rhynland for the loss of 45,230 
 acres of the boezem or catch-water 
 basin, a steam-engine of 200-horse 
 power, driving 10 large scoop- 
 wheels, has been erected at Sparn- 
 dam to lift the boezem water over 
 the tide in the Y, or base of the 
 Zuyder Zee, where the rise is on 
 an average only 17 inches. This 
 engine has discharged 30,000,000 
 tons of water in fifteen consecutive 
 days. When the state of the boezem 
 permits the ' Leeghwater,' ' Cru- 
 quius.'and'Lynden' engines to work 
 freely, they discharge on an aver- 
 age 2,000,000 tons in twenty-four 
 hours, and they are capable of doing 
 this down to their full depth. In 
 the month of June, 1849, the three 
 engines discharged 60,000,000 tons 
 water, and lowered the meer one 
 foot; between the 1st of May and 
 1st of December they had lowered 
 the lake 5 feet, and by the autumn 
 of 1850 dry land appeared. (See 
 Table.} 
 
 The 'Leeghwater,' 'Cruquius'and 
 1 Lynden ' engines were contracted 
 for jointly by the Hayle and Per- 
 ran Foundry Companies, Cornwall, 
 and were manufactured and erected 
 under an able director. 
 
 This once formidable meer is now 
 
MERES, DRAINAGE OF. 
 
 Table, arranged chronologically, showing the Lakes, Meers, and Water-places 
 
 which have been drained by mechanical means, and converted into Fertile 
 
 Lands, in the Provinces of North and South Holland, in the Netherlands. 
 
 
 NORTH HOLLAND. 
 
 ii 
 
 SOUTH HOLLAND. 
 
 *8 
 
 
 
 a 
 
 
 P 
 
 [)ate of 
 
 Name of Lake, 
 
 
 I <*> 
 
 Name of Lake, 
 
 
 I* 
 
 Drain- 
 
 Meer, or Water- 
 
 Location near. 
 
 g W 
 
 Meer, or Water- 
 
 Location near. 
 
 gw 
 
 age. 
 
 place. 
 
 
 .S 
 
 place. 
 
 
 JJ 
 
 1440 
 
 Nesch Meer 
 
 Wervershoofd 
 
 59 
 
 
 
 
 1460 
 1553 
 
 Burghornder Do. 
 The Zyp 
 
 Burghorn 
 Schagerbrug 
 
 684 
 9026 
 
 
 
 
 1555 
 
 Egmonder Meer 
 
 Egmond 
 
 0080 
 
 
 
 
 1560 
 
 Berger Do. 
 Daal Do. 
 
 Bergen 
 Koedyk 
 
 1:94 
 285 
 
 
 
 
 1561 
 
 Vrooner Do. 
 
 St. Pancras 
 
 246 
 
 
 
 
 1566 
 
 Achter Do. 
 
 Alkmaar 
 
 78 
 
 
 
 
 
 Kooi Do. 
 
 Do. 
 
 33 
 
 
 
 
 1567 
 
 Zwyns Do. 
 
 Oudorp 
 
 38 
 
 
 
 
 1580 
 
 Boekeler Do. 
 
 Akersloot 
 
 745 
 
 
 
 
 1607 
 
 Wog Do. 
 
 Spierdyk 
 
 1541 
 
 
 
 
 1608-12 
 
 The Beemster 
 
 Purmerend 
 
 6369 
 
 
 
 
 
 
 The Weiring- ^ 
 erwaard i 
 
 Colkom 
 
 3979 
 
 
 
 
 1614 
 
 .. 
 
 .. 
 
 
 Soetermeersche \ 
 Meer J 
 
 Soetermeer 
 
 1285 
 
 1616 
 
 TjaarlingerMeer 
 
 Warmenhuizen 
 
 98 
 
 
 
 
 l6l 8-22 
 
 Purmer Do. 
 
 Purmerend 
 
 6260 
 
 
 
 
 1622 
 
 . . 
 
 
 
 The Lisserpoel 
 
 Lisse 
 
 533 
 
 1624 
 
 Baarsdorper Do. 
 
 Berk'hout 
 
 4*01 
 
 Hem Meer 
 
 Sassenheim 
 
 149 
 
 
 TheEngeWor-y 
 
 Near Worme- ~\ 
 
 241 
 
 
 
 
 M 
 
 mer J 
 
 meer J 
 
 
 
 
 
 1625 
 
 The Hr. HuO 
 gowaard / 
 
 Langendyk 
 
 6904 
 
 
 
 
 ,, 
 
 Broeker Meer { 
 
 Broek & Wa- \ 
 ter-land J 
 
 638 
 
 
 
 
 1625-28 
 
 Belmer Do. 
 
 Monnikendam 
 
 3)0 
 
 
 
 
 
 Buikslooter Do. 
 
 Buiksloot 
 
 772 
 
 
 
 
 l&N 
 
 The Groot Waal 
 
 Berkhout 
 
 138 
 
 
 
 
 
 W r ormer Meer 
 
 Gisp 
 
 3786 
 
 
 
 
 1626-29 
 
 
 
 
 Diemer Meer 
 
 Diemen 
 
 1575 
 
 1630 
 
 Benning Do. 
 
 Abbe'kerk 
 
 245 
 
 
 
 
 
 Harger & Pet- >. 
 temer Polder / 
 
 Petten 
 
 987 
 
 
 
 
 1631 
 
 The Tien Meeren 
 
 Haring Garspel 
 
 4647 
 
 
 
 
 
 The Drie Do. 
 
 Oud Garspel 
 
 730 
 
 
 
 
 
 Kley Meer 
 
 Koedyk 
 
 147 
 
 
 
 
 ' 
 ' 
 
 Kerk Do. 
 
 Do. 
 
 48 
 
 
 
 
 
 Deble Do. 
 
 Warmenhuizen 
 
 31 
 
 
 
 
 
 Greb Do. 
 
 Do. 
 
 201 
 
 
 
 
 ,, 
 
 The Vier \ 
 Meertjes J 
 
 Medenblyk 
 
 680 
 
 
 
 
 )} 
 
 Braak Meer 
 
 Eerstwoude 
 
 69 
 
 
 
 
 
 Veenhuizer Do. 
 
 Veenhuizen 
 
 718 
 
 
 
 
 
 Schals Do. 
 
 Knollendam 
 
 145 
 
 
 
 
 1632 
 
 Schremer Do. 
 
 N.&S.Schermer 
 
 12938 
 
 
 
 
 1633 
 
 The Vier i 
 Meertjes / 
 
 Obdam 
 
 142 
 
 
 
 
 1636 
 
 Berk Meer 
 
 Veenhuizen 
 
 596 
 
 
 
 
 1640 
 
 Kolk Do. | 
 
 Lambert Scha- \ 
 
 220 
 
 
 
 
 1642 
 
 I 
 
 gen J 
 
 
 Slooter Meer 
 
 
 199 
 
 1643 
 
 Star Do. 
 
 Oostgrafdyk 
 
 1447 
 
 
 
 
 1644 
 
 Noordeinder Do. 
 
 Graft 
 
 409 
 
 
 
 
 1645 
 1646 
 
 Sap Do. 
 
 The Ryp 
 
 51 
 
 The Wilde ) 
 Veneen J 
 
 Moerkapel 
 
 1322 
 
 1650 
 
 
 .. 
 
 
 Stom Meer 
 
 Aalsmeer 
 
 409 
 
 981 
 
MERES, DRAINAGE OF. 
 
 Hate of 
 Drain- 
 age. 
 
 NORTH HOLLAND continual. 
 
 Area drained 
 in Eng. acres. 
 
 SOUTH HOLLAND-ccmttnued. 
 
 IArea drained 
 in Eng. acres. 
 
 Name of Lake, 
 Meer, or Water- 
 place. 
 
 Location near. 
 
 Name of Lake, 
 Meer, or Water- 
 place. 
 
 Location near. 
 
 1666 
 
 
 
 
 Wassenarsche \ 
 Polder J 
 
 Rhynsaterwoude 
 
 2488 
 
 1663 
 
 .. 
 
 
 
 The Driemansi 
 Do. ; 
 
 Soetermeer 
 
 2013 
 
 16/4 
 
 .. 
 
 
 t ~ 
 
 Horn Meer 
 
 Aalsmeer 
 
 441 
 
 1700 
 
 .. 
 
 .. 
 
 
 Binnenweg- " 
 sche Polder J 
 
 Zegwaard 
 
 2247 
 
 
 
 
 
 H. Geest Polder 
 
 Leyrninden 
 
 384 
 
 1715 
 
 
 
 |[ 
 
 Goger Do. 
 
 Alkemade 
 
 607 
 
 1727 
 
 . . 
 
 
 
 Katjes Do. 
 
 Zevenhuizen 
 
 772 
 
 1736 
 
 
 
 .. 
 
 The Starre- ") 
 vaarts Do. ) 
 
 Stompwyk 
 
 443 
 
 1736-44 
 
 .. 
 
 .. 
 
 .. 
 
 The Vier Am. 1 
 hachts Do. J 
 
 Esselykerwoude 
 
 518 
 
 1741 
 
 .. 
 
 .. 
 
 
 Vrieskoopsche \ 
 Do. J 
 
 Vriezekoop 
 
 1325 
 
 1/54-62 
 
 
 .. 
 
 
 Endragts Do. 
 
 Zevenhuizen 
 
 2473 
 
 1758-59 
 
 . . 
 
 
 V 
 
 Damhouder Do. 
 
 Stompwyk 
 
 949 
 
 1759-65 
 
 . . 
 
 
 
 Novider Plas 
 
 Hazerswoude 
 
 8415 
 
 1760-62 
 
 
 .. 
 
 
 Palenternsche \ 
 Polder ; 
 
 Zegwaard 
 
 1279 
 
 1763-66 
 
 
 
 
 Ouwendyksche \ 
 & Boe Do. J 
 
 Esselykerwoude 
 
 806 
 
 1764 
 
 . 
 
 .. 
 
 
 Bovenkerker Do. 
 
 Amstelveen 
 
 3412 
 
 
 
 
 
 Great and Lit- T 
 
 
 
 1767-68 
 
 .. 
 
 
 
 
 tie Kalko- \ 
 vensche Do. J 
 
 Oudshoorn 
 
 1318 
 
 |f 
 
 . . 
 
 
 m< 
 
 TheGroote Do. 
 
 Soetermeer 
 
 1686 
 
 1768-71 
 
 
 
 
 Do. Do. 
 
 Stompwyk 
 
 11/8 
 
 1772-77 
 
 
 .. '.. 
 
 *j 
 
 Berkelsche Do. 
 
 Berkel 
 
 2171 
 
 1/72-82 
 
 .. 
 
 
 
 Bleiswyksche \ 
 Drainage / 
 
 Bleiswyk 
 
 8299 
 
 1/73-80 
 
 .. 
 
 .. 
 
 
 Schiebroksche i 
 Polder / 
 
 Shibroek 
 
 1457 
 
 1781-84 
 
 .. 
 
 .. 
 
 
 Vendeer en \ 
 Lyker Do. J 
 
 Alkemade 
 
 1373 
 
 1782-89 
 
 .. 
 
 .. 
 
 
 Pynakercke 'Jo. 
 
 Pynacker 
 
 1270 
 
 1786-88 
 
 .. 
 
 .. 
 
 .. 
 
 Aarlander- \ 
 veensche Do. / 
 
 Aarlanderveen 
 
 1171 
 
 1788-91 
 
 .. 
 
 .. 
 
 
 Zestienho- 1 
 vensche Do. J 
 
 Overschie 
 
 1064 
 
 1788-99 
 
 .. 
 
 .. 
 
 
 Schieveensche i 
 Do. / 
 
 Ovcrschie 
 
 654 
 
 179<O 
 18JOJ 
 
 .. 
 
 .. 
 
 .. 
 
 Mvdrechtschc \ 
 Do. / 
 
 Mydrecht 
 
 2622 
 
 1797) 
 
 
 
 
 Niewekoopsche") 
 en Zevenho- v 
 
 Niewekoop 
 
 1571 
 
 1809.) 
 
 
 
 
 venesche Do. J. 
 
 
 
 1798-99 
 
 
 .. 
 
 
 Gnephoek en \ 
 Vrowe Do. / 
 
 Oudshoorn 
 
 254 
 
 17997 
 1801 J 
 
 
 .. 
 
 
 Bieslandsche Do. 
 
 Nootdorp 
 
 333 
 
 1810 
 
 .. 
 
 .. 
 
 .. 
 
 Kleine Slarre- \ 
 vuartscheDo. J 
 
 Leydschendam 
 
 23 
 
 1820 
 
 
 
 __ 
 
 Bylmer Meer 
 
 Weesp 
 
 1470 
 
 1828-40 
 
 
 
 
 The Zuid Plas 
 
 Rotterdam 
 
 14820 
 
 1842 
 
 .. 
 
 .. 
 
 .. 
 
 Nootdorpsche > 
 Plas 
 
 Delft 
 
 2500 
 
 
 . 
 
 
 
 Haarlem Lake'1 
 
 Amsterdam, T 
 
 
 1840-50 
 
 .. 
 
 .. 
 
 
 
 (not yet com- > 
 pleted) J 
 
 Haarlem and > 
 Leyden J 
 
 45230 
 
 
 
 
 
 
 In South Holland, acres 124505 
 
 
 
 
 98557 
 
 In North Do. Do. 98557 
 
 
 
 
 
 Total Acres 2231)62 
 
MER 
 
 MERIDIAN. 
 
 MES 
 
 a drained district, and is most pro- 
 fitably occupied by industrial agri- 
 cultural pursuits. 
 
 It may be said in this instance, 
 the Dutch have realized the fable 
 of the ' Hare and the Tortoise : ' 
 in 1840, the erection of a steam- 
 engine of 30 or 40-horse power, 
 for drainage purposes, was thought 
 to be a bold step, whereas, under 
 the guidance of English engineers, 
 they have dared, between 1840 and 
 1842, to erect the most gigantic 
 steam machinery in the world. 
 
 The low lands of the Nether- 
 lands are divided into large drain- 
 age districts, which have been em- 
 banked against the inroads of the 
 tides and river floods ; and the va- 
 rious parts of a district are con- 
 nected by what is called the boezem, 
 or water-basin, or reservoir, formed 
 by the rivers, lakes, meers, or water- 
 places having their origin in the 
 district, and serves to receive the 
 water drained either naturally or 
 artificially from the surrounding 
 lands. The boezem is put into 
 communication with the exterior 
 waters of the rivers or sea by locks 
 and sluices. All lands in a given 
 drainage district above the level of 
 the boezem, and draining naturally 
 into it, are called ' boezem lands.' 
 All lands lying below the boezem, 
 and drained into it by machinery, 
 are called polders. Of polders there 
 are two kinds : the first are seldom 
 more than 2 or 3 feet below the 
 level of the boezem, which is em- 
 banked above the natural surface 
 of the land : of such polders there 
 are upwards of 1000 in the pro- 
 vince of South Holland only ; and 
 they are kept dry by the aid of an 
 immense number of windmills. Of 
 the second class of polders there 
 are 43 in North Holland and 43 in 
 South Holland, as recorded in the 
 precedingTable,and these are works 
 of a formidable character, being, for 
 the most part, the beds of lakes, or 
 permanent sheets of water, varying 
 in depth from 5 to 20 feet below 
 
 283 
 
 the boezem, and requiring powerful 
 machinery to pump them out in 
 the first instance, and to maintain 
 them dry afterwards ; and as these 
 lakes, etc., always form part of the 
 boezem, or reservoir, of a much 
 larger tract of land, their drainage 
 frequently involves the construction 
 of immense works, and seriously 
 affects the prosperity of the whole 
 district in which they are situate. 
 
 The preceding Table will, as an 
 apt illustration of the subject of 
 draining large districts, be found 
 important in engineering history. 
 
 By the Table it will be seen that 
 the North Hollanders had effected 
 the drainage of nearly all their 
 lakes, etc., as early as 1645, and 
 they had then recovered 98,557 
 acres of land forming their beds ; 
 whereas the South Hollanders had 
 in 1645 only drained five small 
 lakes, whose area was only 3741 
 acres. It must be observed that 
 the South Holland drainages are of 
 a much more extensive character 
 than those of North Holland, and 
 the difficulties to be overcome were 
 much greater; and last, but not 
 least, the North Hollanders were 
 much richer than their neighbours. 
 Of the 223,000 acres of lakes, etc., 
 recorded in the Table, upwards of 
 50,000 acres were formed artifi- 
 cially, by dredging the peat pulp 
 to the depth of 10 or 20 feet, to 
 serve as fuel for domestic pur- 
 poses, etc. 
 
 Meridian, in astronomy, the line 
 drawn from the north to the south, 
 through the zenith, nadir, and poles, 
 which line the sun crosses at noon. 
 
 Merlon, the solid part of an embattled 
 parapet, standing up between the 
 embrasures. 
 
 Merus, the plain surface between the 
 channels of a triglyph. 
 
 Mesaula, a passage, gallery, or lobby ; 
 an entry or court. 
 
 Messuage,^ dwelling-house,withsome 
 land adjoining, as garden, orchard, 
 etc., and all other conveniences be- 
 longing to it. 
 
MES 
 
 METALS. 
 
 MET 
 
 Nestling, brass ornaments ; candje- 
 sticks ; sacred utensils used in 
 Anglo-Saxon times. 
 
 Metallurgy, the art of working me- 
 tals, invented by Tubal-Cain, B. c. 
 3608. "And Zillah also bare Tubal- 
 Cain, an instructor of every arti- 
 ficer in brass and iron." (Gen. iv. 
 22.) In the earliest periods of his- 
 tory, mention is made of the ex- 
 cellence in working metals among 
 the Egyptians. Some specimens of 
 metal-work of an early date ex- 
 ist, and modern fashion has also 
 produced some very elaborate ex- 
 amples. 
 
 Metals are elementary bodies capable 
 of combining with oxygen ; and 
 many of them, during this combi- 
 nation, exhibit the phenomenon of 
 combustion. Seven metals only 
 were formerly known ; but recently 
 a much greater number has been 
 added. Metals are distinguished 
 by their great specific gravity, con- 
 siderable tenacity, and hardness, 
 opacity, and property of reflecting 
 the greater part of the light which 
 falls on their surface, giving rise to 
 metallic lustre or brilliancy. Me- 
 tals are the best conductors of 
 caloric : their expansibilities are 
 various, and are probably nearly in 
 the order of their fusibilities. Mer- 
 cury melts at so low a temperature, 
 that it can be obtained in the solid 
 state only at a very low tempera- 
 ture; others,' as platina, can scarcely 
 be melted by the most intense heat 
 which we can excite. 
 
 Metals employed in the mechanical 
 arts. 
 
 ANTIMONY is of a silvery white 
 colour, brittle, and crystalline in its 
 ordinary texture : it fuses at about 
 800-: its specific gravity is 6712. 
 BISMUTH is a brittle, white me- 
 tal with a slight tint of red : its spe- 
 cific gravity is 9 '822 : it fuses at 4 7 6, 
 and always crystallizes on cooling. 
 COPPER is the only metal, with 
 the exception of titanium, which has 
 a red colour: it has much lustre, 
 is very malleable and ductile, and 
 
 284 
 
 exhales a peculiar smell when 
 warmed or rubbed : it melts at a 
 bright red or dull white heat, or at 
 a temperature intermediate be- 
 tween the fusing points of silver 
 and gold = 1996 Fahr. : its specific 
 gravity varies from 8-86 to 8*89, 
 the former being the least density 
 of cast copper ; the latter, the great- 
 est of rolled or hammered copper. 
 
 GOLD is of a deep and peculiar 
 yellow colour ; it melts at a bright 
 red heat, equivalent, according to 
 Daniell, to 2016 Fahr., and when 
 in fusion, appears of a brilliant 
 greenish colour: its specific gra- 
 vity is 19-3: it is so malleable, 
 that it may be extended into leaves 
 which do not exceed the -^ Ti . 1 uou th 
 of an inch in thickness, or a single 
 grain may be extended over 56 
 square inches of surface. 
 
 LEAD in colour is bluish-white : 
 it has much brilliancy, is remark- 
 ably flexible and soft, and leaves a 
 black streak on paper. When han- 
 dled, it exhales a peculiar odour : 
 it melts at about 612, and by the 
 united action of heat and air, is 
 readily converted into an oxide. 
 Its specific gravity, when pure, is 
 11 '445 ; but the lead of commerce 
 seldom exceeds 11-35. Lead is 
 used, in a state of comparative 
 purity, for roofs, cisterns, pipes, 
 vessels for sulphuric acid, etc. 
 
 MERCURY is a brilliant white 
 metal, having much of the colour 
 of silver. It has been known from 
 remote ages. It is liquid at com- 
 mon temperatures, solid and mal- 
 leable at 40 Fahr., and contracts 
 considerably at the moment of con- 
 gelation : it boils and becomes va- 
 pour at about 670 : its specific 
 gravity at 60 is 13"5. In the solid 
 state, its density exceeds 14. The 
 specific gravity of mercurial vapour 
 is 6-976. 
 
 NICKEL is a white brilliant 
 metal, which acts upon the magne- 
 tic needle, and is itself capable of 
 becoming a magnet. Its magnetism 
 is more feeble than that of iron 
 
MET 
 
 METALS. 
 
 MET 
 
 and vanishes at a heat somewhat 
 helow redness. At 630 it is duc- 
 tile and malleable : its specific gra- 
 vity varies from 8'27 to 8 -40 when 
 fused, and after hammering, from 
 8-69 to 9-00. It is not oxidized hy 
 exposure to air at common tempe- 
 ratures ; but when heated in the 
 air, it acquires various tints, like 
 steel : at a red heat, it becomes 
 coated by a grey oxide. 
 
 PALLADIUM is of a dull white 
 colour, malleable and ductile. Its 
 specific gravity is about 11-3, or 
 11-86 when laminated. It fuses at 
 a temperature above that required 
 for the fusion of gold. 
 
 PLATINUM is a white metal, 
 extremely difficult of fusion, and 
 unaltered by the joint action of 
 heat and air. It varies in den- 
 sity from 21 to 2T5, according to 
 the degree of mechanical compres- 
 sion it has sustained. It is ex- 
 tremely ductile, but cannot be 
 beaten into such thin leaves as gold 
 and silver. 
 
 RHODIUM, discovered in 1803 
 by Dr. Wollaston, is a white metal, 
 very difficult effusion. Its specific 
 gravity is about 11 ; it is extremely 
 hard. When pure, the acids do not 
 dissolve it. 
 
 SILVER is of a more perfect 
 white than any other metal : it has 
 considerable brilliancy, and takes a 
 high polish. Its specific gravity 
 varies between 10'4, which is the 
 density of cast silver, and 10 5 to 
 10*6, which is the density of rolled 
 or stamped silver. It is so mallea- 
 ble and ductile, that it may be ex^ 
 tended into leaves not exceeding a 
 ten-thousandth of an inch in thick- 
 ness, and drawn into wire much 
 finer than a human hair. Silver 
 melts at a bright red heat, estimated 
 at 1873 Fahr., and when in fusion 
 appears extremely brilliant. 
 
 TIN has a silvery white colour, 
 with a slight tint of yellow : it is 
 malleable though sparingly ductile, 
 Common tin-foil, which is obtained 
 by beating out the metal, is not 
 
 285 
 
 more than y^Vvtii of an inch in 
 thickness,and what is termed ' white 
 Dutch metal ' is in much thinner 
 leaves. Its specific gravity fluctuates 
 from 7'28 to 7 '6, the highest being 
 the purest metal. When bent, it 
 occasions a peculiar crackling noise, 
 arising from the destruction of co- 
 hesion amongst its particles. When 
 a bar of tin is rapidly bent back- 
 wards and forwards several times 
 successively, it becomes so hot that 
 it cannot be held in the hand. 
 When rubbed, it exhales a peculiar 
 odour. It melts at 442, and by 
 exposure to heat and air is gradu- 
 aily converted into a protoxide. 
 
 ZINC is a bluish-white metal, 
 with considerable lustre; rather 
 hard ; of a specific gravity of about 
 6*8 in its usual state ; but when 
 drawn into wire, or rolled into 
 plates, its density is augmented to 
 7 or 7'2. In its ordinary state, at 
 common temperatures, it is tough, 
 and with difficulty broken by blows 
 of the hammer: it becomes very 
 brittle when its temperature ap- 
 proaches that of fusion, which is 
 about 773; but at a temperature 
 a little above 212, and between 
 that and 300, it becomes ductile 
 and malleable, and may be rolled 
 into thin leaves, and drawn into 
 moderately fine wire, which, how- 
 ever, possesses but little tenacity. 
 When a mass of zinc which has 
 been fused is slowly cooled, its 
 fracture exhibits a lamellar and 
 prismatic crystalline texture. The 
 pipes of the great organ in the 
 town-hall at Birmingham, and in 
 that of York cathedral, are made 
 principally of sheet zinc. 
 
 Aluminium, a newly discovered 
 metal; see p. 12. 
 
 Meteorology, the term now used for 
 the purpose of designating the sci- 
 ence which observes, registers, clas- 
 sifies, and compares the various and 
 varying phenomena of our atmo- 
 sphere. It remarks, at the same 
 time, the connection of those phe- 
 nomena with the heavenly bodies, 
 
 N3 
 
MET 
 
 METEOROLOGY. 
 
 MIL 
 
 and with the solid and liquid rtla- 
 terials of the earth, in reference to 
 their reciprocal and combined in- 
 fluence in determining the character 
 of different climates, and with the 
 view of learning the meteoric his- 
 tory of every region of our globe, 
 of ultimately investigating the laws 
 of atmospheric change, the plan of 
 meteoric action ; the theory, in fact, 
 of meteorological phenomena, on 
 which depend essentially the fit- 
 ness of the various portions of the 
 earth's surface for the production 
 of different vegetable and other sub- 
 stances and for the support of ani- 
 mal life. 
 
 Meteorological phenomena are not con- 
 fined to the inferior regions of the 
 atmosphere, but extend as far as 
 observations have reached. It is 
 possible their influence may extend 
 universally, and therefore it is de- 
 sirable to know whether there exists 
 throughout space a medium, or con- 
 ductor, or whether there is such a 
 thing in nature as vacuum. Some 
 have, it is true, endeavoured to re- 
 concile opinions so diametrically 
 opposed to each other,by suggesting 
 that the universe, though infinite, 
 is a plenum anu a void ! This (the 
 doctrine of Leucippus) a recent au- 
 thor declares to be really true; 
 and some conceive that the New- 
 tonian theory necessarily implies 
 the reality of a void, the astrono- 
 mical calculations on which that 
 theory rests having been made 
 without any allowance for the re- 
 sistance to the motions of the 
 planets,which might be experienced 
 from a material medium. 
 
 Metoche, the intervals between two 
 denticuli in the Ionic entablature. 
 
 Metope, the spaces between the tri- 
 glyphs of the Doric frieze, which 
 in the Parthenon, for instance, were 
 filled in with sculpture; but in 
 mo '.ern porticoes that are said to 
 be after the Parthenon, they are 
 mere blanks. 
 
 Metre, a French measure, equal to 
 39-3702 English inches. 
 
 286 
 
 Mezuzoth, a name given to certain 
 pieces of parchment which were 
 anciently fixed on the door-posts of 
 houses. 
 
 Mezzanine, a low intermediate story 
 between two higher ones. 
 
 Mezzo-relievo, projection of figures 
 between alto- and basso-relievo ; 
 demi-relievo. 
 
 Mezzotinto,3i\imA of engraving nearly 
 resembling painting, effected by 
 scraping and burnishing the copper. 
 
 Mica, an important ingredient in the 
 composition of rocks, consisting of 
 silica, alumina, oxide of iron, and 
 potash : it is easily divided into 
 laminae, even to the s-ooVo(7 tn P arfc 
 of an inch, and is distinguishable 
 from talc by its elasticity : in Russia 
 it is used instead of window-glass. 
 
 Micrometer, an instrument for mea- 
 suring small spaces. 
 
 Microscope, an optical instrument for 
 rendering visible minute objects : 
 the simple microscope has one lens 
 only, and magnifies by permitting 
 a near view of the object ; in the 
 compound microscope, a focal image 
 is again magnified by other lenses. 
 
 Middle-ground is a term used, not to 
 express the middle of a picture, but 
 generally perspectively so ; some- 
 times it is the highest part of a 
 picture, and sometimes the second 
 degree of shade. Pictures are di- 
 vided into three parts : fore-ground, 
 middle-ground, and back-ground. 
 
 Middle-rail, the rail of a door which 
 is upon a level with the hand when 
 hanging freely : the lock of the door 
 is generally fixed in this rail. 
 
 Midship signifies the middle of a ship. 
 
 Midship-bend, the broadest frame in 
 the ship, called the ' dead-flat. ' 
 
 Milestones. Pliny says, the miles on 
 the Roman roads were distinguished 
 by a pillar, or"a stone, set up at the 
 end of each of them, and which was 
 marked with one or more figures, 
 signifying how far it was from the 
 Milliarium Aureum, a pillar in the 
 forum near the temple of Saturn, 
 which had on it the figure I., so 
 that the next pillar to it, which was 
 
MIL 
 
 MILLS. 
 
 MIN 
 
 marked II., was but one mile from 
 the standard pillar.and consequently 
 the XIV. and XI. stones were but 
 thirteen and ten miles from the 
 forum. 
 
 Millennium, a thousand years ; the 
 term applied to that period of the 
 Christian Church described in Re- 
 velation, during which, according to 
 many commentators, it is supposed 
 that Jesus Christ will reign person- 
 ally on the earth, that the bodies 
 of martyrs and other eminent 
 Christians will be raised from the 
 dead, and in this renewed state 
 constitute the subjects of His glo- 
 rious kingdom. 
 
 Milliare, a Roman mile, consisting 
 of 1000 paces of 5 feet each, and 
 therefore = 5000 feet: taking the 
 Roman foot at 11-6496 English 
 inches, the Roman mile would be 
 1618 English yards, or 142 yards 
 less than the English statute mile. 
 
 Mills for the grinding of grain into 
 flour are of several kinds : wind- 
 mills, with sails to be impelled by 
 the action of the wind, over-shot 
 and under-shot ; and the horizon- 
 tal or turbine water-wheels. Mill 
 machinery is used for the grinding 
 of tobacco into snuff, impelled by 
 wind, particularly in Holland, where 
 stupendous structures can be seen 
 on the road from Rotterdam to the 
 Hague. Mills are alsoused,propelled 
 by steam or water, for the grinding 
 of bark, preparing of flax, sawing 
 of timber, and for the many and 
 varied purposes in manufacture. 
 In the ' Papers on Engineering,' 
 vol. vi., will be found an interesting 
 paper by Mr. Fairbairn on ' \Vatr- 
 Wheels with Ventilated Buckets.' 
 
 Millwrights' Planing Machine. This 
 machine is similar in principle to 
 the ordinary plaifing machine (see 
 Planing Machine], except in cases 
 where heavy work is required to be 
 planed, when a machine with a 
 movable tool and fixed table is 
 used. The advantage of this ar- 
 rangement is, that very large and 
 heavy castings are planed, which 
 
 287 
 
 could not be moved to and fro, as 
 in the ordinary machines, without 
 great loss of power. It is placed 
 over a pit made for the purpose, 
 with steps to descend into it. The 
 two side frames are bolted to the 
 ground, and the table has a series 
 of apertures for bolts to fix the 
 work upon it, and can be raised or 
 lowered to any required height by 
 four strong screws, one at each 
 corner. The horizontal and ver- 
 tical slides are placed over the work 
 in the usual manner, and are at- 
 tached to a light frame, which, 
 when the tool is adjusted to the 
 work by the vertical slide, is moved 
 to and fro, carrying with it the 
 slides and tool, and at the end of 
 each backward stroke a lappet, or 
 other contrivance, sets the vertical 
 slide and tool a little further across 
 the table, until the entire surface is 
 planed. 
 
 Minaret, in Mohammedan architec- 
 ture, a spire or steeple. 
 
 Mind of Man. For the purposes of 
 anatomy every skeleton may be 
 useful, and may sufficiently tell the 
 tale of the race'to which it belongs, 
 but when we come to seek for high 
 beauty and for approaches to per- 
 fection, of how infinite a diversity, 
 of what countless degrees, does 
 form appear to be susceptible ! 
 How difficult it is to find these, 
 except in mere fragments ; and 
 how dangerous does it prove, in 
 dealing with objects, to treat the 
 whole as a normal specimen, simply 
 because parts are fine, or even su- 
 perlative. When, again, we pass 
 onward, and with the body regard 
 also the mind of man, still greater 
 is the range of difference, and still 
 more rare is either the develop- 
 ment of parts in a degree so high 
 as to bring their single excellence 
 near the ideal standard, or the ac- 
 curate adjustment of their rela- 
 tions to one another, or the com- 
 pleteness of the aggregate which 
 they form. (Gladstone.) 
 
 Mineral Black is a native and impure 
 
MIN 
 
 MINING. 
 
 MIN 
 
 oxide of carbon, of a soft textwre, 
 found in Devonshire. 
 
 Mineral Green is the commercial 
 name of green lakes, prepared from 
 the sulphate of copper. 
 
 Mineralogy forms one of the three 
 great divisions into which natural 
 history or the knowledge of natu- 
 ral objects has been classified ; the 
 other two being botany, devoted to 
 plants, and zoology, to animals. 
 Mineralogy is also distinguished 
 from geology, inasmuch as it re- 
 gards the characters of minerals 
 in detail, without regard to their 
 formation and general distribution 
 in the crust of the earth, which 
 belong to geology. If the compo- 
 sition of a mineral substance is to 
 be considered, then mineralogy 
 forms a portion of chemistry ; but 
 in its more limited sense, mine- 
 ralogy is the art of distinguishing 
 mineral substances from each other, 
 and the science of accurately de- 
 scribing and arranging them, by 
 what may be termed a natural clas- 
 sification. 
 
 Minerva in a speech expresses to Juno 
 her resentment at the restraint put 
 upon her by Jupiter. She accuses 
 him of forgetting the services she 
 had so often rendered to Hercules 
 when he was oppressed by the la- 
 bours that Eurystheus had laid 
 upon him, and declares that it was 
 she who effected his escape from 
 Hades. (Gladstone.) 
 
 Minerva in her capacity of a tradi- 
 tive deity was with perfect consis- 
 tency worshiped alike among Tro- 
 jans and Greeks, Hellenic and Pe- 
 lasgian tribes; there is nothing 
 strange, then, in our finding her 
 the patroness of a Pelasgian peo- 
 ple. (Gladstone.) 
 
 Mines. "Water-springs in mines are 
 wrongly considered to be of great 
 injury. It is true, the lifting of 
 water by machinery from the deep 
 mines is attended with expense, 
 when they are so situated that' no 
 level, drift, or watercourse can be 
 obtained for that purpose ; but, on 
 
 9Q 
 
 the other hand, they are so abso- 
 lutely necessary in mining, that in 
 the very first process, a judicious 
 miner, in boring down to his mine, 
 previous to his sinking to or work- 
 ing it, even in this simple act, 
 cannot proceed very deep without 
 water to work his bore-rod in ; and 
 if the strata of the earth passed 
 through does not produce it, he 
 must pour it down the bore-hole, 
 or he cannot proceed. When all 
 his pits or shafts are sunk, and his 
 mine opened, and ventilation is re- 
 quired to expel inflammable air, 
 fire, or black damp (as it is termed), 
 nothing is superior to water. When 
 this can be obtained, and made to 
 run with facility through the mine 
 and its various workings, it is found 
 superior to air-furnaces of any kind 
 for expelling the fulminating va- 
 pours so destructive to the health 
 and lives of the workmen employed. 
 
 Mines in Scotland. The general cus- 
 tom of Scotland provides for yield- 
 ing to the landlord a royalty pro- 
 portioned upon the net amount of 
 sales at the colliery, in conjunction 
 with a certain or sleeping rent pay- 
 able half-yearly. The royalty pro- 
 portion is sometimes so high as 
 one-quarter the amount of sales, 
 but generally one-eighth ; of late 
 years many collieries have been let 
 at one-twelfth and at one-four- 
 teenth the amount of sales. 
 
 Mining. There is an essential differ- 
 ence between civil and military 
 mining : in the former, the works 
 are frequently carried on at consi- 
 derable depths below the surface 
 of the earth, and sometimes in solid 
 rock ; whereas military mining is 
 what may be termed superficial, 
 and consequently the miner works 
 through the m^re recent formations 
 of earths and sands, which, from 
 their little tenacity, he has to sup- 
 port as he advances. For the bet- 
 ter ventilation of military mines, a 
 machine has been invented by Ser- 
 geant Lewis, of the Royal Sappers 
 and Miners ; and it has been con- 
 
MIN 
 
 MIXED COLOURS. 
 
 MOD 
 
 jectured that Mr. Haig's patent 
 pneumatic engine, invented for the 
 purpose of purifying the holds of 
 vessels, might also be successfully 
 employed in mining operations. 
 
 Minster, a cathedral, anciently a large 
 church. (See Westminster Abbey.} 
 
 Minute, a proportionate measure in 
 architecture, by which the parts of 
 the orders are regulated ; the six- 
 tieth part of the lower diameter of 
 the shaft of a column, written thus, 
 10', i.e. ten minutes ; in geography 
 and astronomy, the sixtieth part of 
 a degree. 
 
 Miserere, projecting brackets in the 
 under side of the seats of stalls in 
 churches ; they are always more 
 or less ornamented with carvings of 
 leaves and grotesque subjects. 
 
 Mitre, an episcopal crown. In carpen- 
 try, the line formed by the meeting 
 of mouldings or other surfaces 
 which intersect each other. If 
 two pieces of wood be formed to 
 equal angles, or if the two sides of 
 each piece form equal inclinations, 
 and thus be joined together at their 
 common vertex, so as to make an 
 angle double to that of either 
 piece, they are said to be mitred 
 together, and the joint is called 
 4 the mitre.' 
 
 Mitre-wheel, a wheel having teeth 
 formed so as to work at an angle 
 of 45 to the centre line of the 
 shaft on which it is fixed, to move 
 with another wheel of equal size, 
 fixed on a shaft at right angles to 
 the former one 
 
 Mixed Citrine. There are two prin- 
 ciples of combination, of which the 
 artist may avail himself in pro^ 
 ducing these colours ; the one being 
 that of combining two original se- 
 condaries, green and orange, in pro- 
 ducing a citrine ; *the other, the 
 uniting the three primaries in such 
 a manner that yellow may predomi- 
 nate in the case of citrine, and blue 
 and red be subordinate in the com- 
 pound. 
 
 Mixed Greys are formed by the 
 compounding of black and white, 
 
 289 
 
 which yields neutral greys, and of 
 black and blue, black and purple, 
 black and olive, etc. 
 
 Mixed Greens, compounds of blue 
 and yellow pigments, which may 
 be formed by compounding them 
 in the several ways of working, or 
 by blending them in the propor- 
 tions of the various hues required. 
 
 Mixed Olive is compounded by unit- 
 ing green and purple colours, or by 
 adding to blue a smaller proportion 
 of yellow and red, or by breaking 
 much blue with little orange. 
 
 Mixed Orange. Orange being a colour 
 compounded of red and yellow, the 
 place of original orange pigments 
 may be supplied by a mixture of 
 the two latter colours, by glazing 
 one over the other; by stippling, 
 or other modes of breaking and 
 intermixing them in working, ac- 
 cording to the nature of the work 
 and the effect required. 
 
 Mixed Purple. Purple being a se- 
 condary colour, composed of blue 
 and red, it follows of course that 
 any blue and red pigments which 
 are chemically at variance may be 
 used in producing a mixed purple 
 of any required hue, either by 
 compounding or by grinding them 
 together ready for use, or by com- 
 bining them in the various modes 
 of operation in painting. 
 
 Mixed Russet. Orange, vermilion, 
 and madder purple afford a com- 
 pound russet pigment of a good 
 and durable colour. 
 
 Mizen-mast, in ship-rigging, the mast 
 next the stern. 
 
 Mock lead, wild lead, black lead, or 
 black jack, a ponderous black mi- 
 neral, which does not readily in- 
 corporate in the fire ; a zinc ore. 
 
 Model, a pattern used for moulding ; 
 a machine or building executed in 
 miniature. 
 
 Modillion, a projecting bracket under 
 the corona of the Corinthian and' 
 Composite orders, and sometimes 
 of the Roman Ionic. 
 
 Module, a measure of proportion by 
 which the parts of an order or of a 
 
MOL 
 
 MONASTERIES. 
 
 MON 
 
 building are regulated in classical 
 architecture ; considered generally 
 as the diameter or semi-diameter 
 of the lower end of the shaft of 
 the column ; in other words, semi- 
 diameter of the column, or 30 mi- 
 nutes. 
 
 Molecule, synonymous with atom, in 
 physics, a very small mass or por- 
 tion of any body. 
 
 Molybdenum, a brittle and white glo- 
 bulous metal. 
 
 Momentum, in dynamics, is the force 
 of a body in motion. When the 
 motion of a body is considered with 
 respect to the mass, or quantity of 
 matter moved, as well as its ve- 
 locity, it is called its momentum, 
 or quantity of motion. The mo- 
 mentum of a body is therefore in 
 the compound ratio of its quantity 
 of matter and velocity. 
 
 Monastery, an establishment for the 
 accommodation of a religious fra- 
 ternity, who made it the receptacle 
 of benevolence and charity for the 
 poor and the way-worn. A con- 
 siderable portion of the land was 
 formerly occupied by the monas- 
 teries and other religious houses 
 which existed in Britain, and the 
 endowments of these establish- 
 ments subsequently became the 
 foundation of the great wealth of 
 some of the early aristocracy in 
 England. 
 
 Of the ample means enjoyed by 
 the inmates of these cloistered sanc- 
 tuaries, some idea may be formed 
 from the following historical state- 
 ment, translated from tb,e preface 
 to the ' Ely Cartulary,' preserved in 
 the Public Library at Cambridge. 
 After the defeat and death of 
 Harold, many of the leading men 
 of the realm, who had strenuously 
 opposed the Bastard, fled for re- 
 fuge to Ely monastery, together 
 with their friends, " laden with 
 their richest treasures," and with- 
 stood, for seven years, the im- 
 petuous threatenings of the Nor- 
 mans, until they were unexpectedly 
 surprised. " Then a council being 
 
 220 
 
 held, it seemed advisable to implore 
 the royal mercy ; upon which some 
 were despatched to the king's 
 court, at that time at Warwick, 
 carrying rich treasures to the king, 
 the gift of atonement and compen- 
 sation of their misconduct ; with 
 which the king was satisfied, but 
 on these terms and conditions, 
 that, during his pleasure, forty 
 royal officers should be lodged at 
 the expense of the monastery. * * 
 The knights are sent for, they 
 arrive, and are present with their 
 household, every one of whom has 
 under him a monk of the first order, 
 as an officer under his earl, or a 
 guest under his host. But the 
 king ordered that the cellarer 
 should dispense provisions to the 
 officers and monks promiscuously 
 in the public hall of the convent. In 
 short, the officers with their earls, 
 the guests with their hosts, the 
 knights with their monks, the 
 monks with their knights, were 
 most grateful to each other; for 
 each and all of them mutually 
 afforded each other the offices of 
 humanity." Afterfive years passed 
 in this way, the knights were re- 
 called by the Conqueror, to assist 
 in punishing the unnatural wicked- 
 ness of his son Robert ; and " they 
 departed with grief; and our monks, 
 wonderful to relate, lamented the 
 departure of these most illustrious 
 companions, heroic knights, and 
 most pleasing guests, not only in 
 tears, but in dismal bowlings and 
 exclamations, and struck their 
 breasts in despair, after the man- 
 ner of a bride whose husband is 
 unseasonably hurried from her 
 sweet embraces to arms. . . All the 
 monks accompanied the knights as 
 far as Haddenham, with hymns, 
 crosses, thuribals, processions, and 
 every solemnity, and, when re- 
 turned, took care to paint the arms 
 of each knight on the walls of the 
 refectory, to the perpetual remem- 
 brance of the uncommon humanity 
 of their military guests." In the 
 
MON 
 
 MORTAR. 
 
 MOR 
 
 cartulary the names of the knights, 
 forty in number, with their com- 
 panions, are given ; and their arms 
 are emblazoned on the margin. 
 
 Monkey -wrench, a spanner with a 
 movable jaw, which can be adjust- 
 ed by a screw or wedge to the size 
 of the nut which it is required to 
 turn. 
 
 Monogram, a cipher composed of two 
 or more letters interwoven as an 
 abbreviation of a name : monograms 
 were common as distinctive marks 
 on ancient coins, and were also 
 used as seals. 
 
 Monolithic, consisting of a single 
 stone; statues, columns, and pillars 
 were formed by the ancients out of 
 large blocks of stone or marble. 
 
 Monopteral, a temple which has no 
 cella, but consists of columns dis- 
 posed in the form of a circle, co- 
 vered with a conical roof. 
 
 Monota, a vase with one handle. 
 
 Monotriglyph, the interval observed 
 between the columns of a Doric 
 portico, where a space is left suf- 
 ficient for the insertion of one tri- 
 glyph only between those imme- 
 diately over two contiguous co- 
 lumns. 
 
 Monstrance, sometimes called Remon- 
 strance, the vessel in which the 
 consecrated wafer or host is placed 
 while the congregation are blessed 
 with it, in the Roman Catholic 
 Church. In the ' Divers Works of 
 Early Masters,' 2 vols. folio, will be 
 found two of the rarest and >nost 
 elaborate examples of tabernacles 
 or canopies, in a compartment of 
 either of which the casket or vessel 
 containing the sacred vessel is de- 
 posited. 
 
 Monton, a heap of ore: a batch under 
 process of amalgamation, varying 
 in different mining districts. 
 
 Monument, a mausoleum or tomb. 
 Sepulchral monuments of the mid- 
 dle ages still exist to a considerable 
 extent, both here and on the Con- 
 tinent. Monuments and tombs of 
 modern date are designed from 
 Classical and Gothic architecture, 
 
 291 
 
 and in many instances are beautiful 
 examples of modern art. 
 
 Moor, in Cornish, a root, or quantity 
 of ore in a particular part of a lode, 
 as a ' moor of ore,' a ' moor of tin.' 
 
 Moorish, Mohammedan, or Saracenic 
 Architecture, is a combination of 
 Egyptian, Grecian, and Roman de- 
 tails ; first established by the Arabs 
 about the tenth century, and for 
 oriental scenery of a pleasing cha- 
 racter: its complicated ornament 
 and lattice- work are rich and pecu- 
 liar. Many existing examples are 
 interesting ; but the style is not 
 adapted to European usages and 
 requirements. 
 
 Moot-hall, or Moot-house, in Saxon 
 times, a building appropriated to 
 assemblies on public affairs; & guild- 
 hall or town-hall; hotel de ville, etc. 
 
 Mora wood. This tree is 100 feet 
 high, and abundant ; it is close- 
 grained, like teak, and superior to 
 oak ; esteemed for ship-building. 
 
 Moresque, a kind of painting, carving, 
 etc., in the arabesque and grotesque 
 styles of ornament. 
 
 Mortar. The materials which are 
 added to lime, in the formation of 
 mortars or calcareous cements, are, 
 1st, the different kinds of sand, 
 properly so called ; 2nd, arenes ; 
 3rd, psammites; 4th, clays; 5th, 
 volcanic or pseudo-volcanic pro- 
 ducts ; and 6th, artificial products 
 arising from the calcination of the 
 clays, the arenes, and the psam- 
 mites ; and the rubbish and slag of 
 manufactories, forges, etc. 
 
 INGREDIENTS OF MORTAR. 
 
 SAND. The granitic, schistose, 
 and calcareous rocks, free-stones, 
 etc., reduced to the state of hard 
 and palpable grains, either by the 
 agitation of water, or by spontane- 
 ous disaggregation, give birth to 
 the various kinds of sand. We dis- 
 tinguish them from powders by 
 their falling at once to the bottom, 
 when thrown into limpid water, 
 and that without altering its trans- 
 parency in any sensible degree. 
 
MOR 
 
 MORTAR. 
 
 MOR 
 
 The disaggregation of rock* is 
 often accompanied by a decompo- 
 sition which produces a powder: 
 this powder renders the sand ' rich,' 
 or, in other terms, susceptible of a 
 certain cohesion, when tempered 
 with water. Washed by rains and 
 currents of water, it is soon freed 
 from the pulverulent particles, and 
 is deposited pure in the beds of 
 rivers. This purity is often changed 
 near the mouths of streams, and in 
 the small rivulets whose tributaries 
 flow over a bed of clay or mould : 
 the sand mixes with vegetable de- 
 bris and animal matters, and be- 
 comes ' loamy.' The particles com- 
 posing sand faithfully represent 
 - those of the rocks whence they 
 are derived. The granitic regions 
 furnish quartz, felspar, and mica ; 
 and the volcanic regions, lavas of 
 all kinds. The tabular-shaped 
 sands, whose particles are tender, 
 are furnished by the schistose 
 mountains. It is difficult for them 
 to be transported far without be- 
 ing reduced to powder. 
 
 The calcareous sands are the 
 least common, probably arising 
 from the fact that rivers generally 
 take their rise from primitive sum- 
 mits, or such as are composed of 
 primitive elements. The calcare- 
 ous rocks, besides, are not suscep- 
 tible of that kind of disaggregation 
 which can be called granitic ; for 
 if they be of a soft kind, they 
 produce powder; if hard, scaly 
 splinters. 
 
 The partial and secondary revo- 
 lutions of the globe have occasioned 
 immense deposits of sand in situa- 
 tions where now neither brooks 
 nor rivers flow : these are the fos- 
 sil sands ; and they should be care- 
 fully distinguished from the virgin 
 sands, which are still in their origi- 
 nal site, and have not been operated 
 on by the waters. 
 
 The fossil sands generally exhibit 
 a more angular grain than the sea 
 or river sands ; but consist for the 
 most part of the same elements, 
 
 292 
 
 sometimes pure, sometimes coloured 
 by ochres, etc. 
 
 Among the fossil sands is one 
 very remarkable, the arene. Its 
 properties entitle it to attention. 
 
 ARENE is a sand, generally 
 quartzose, with very irregular, un- 
 equal grains, and mingled with 
 yellow, red, brown, and sometimes 
 white clay, in proportions varying 
 from one to three-fourths of the 
 whole volume. 
 
 The arene almost always occu- 
 pies the summits of the rounded 
 and moderately-elevated hills: it 
 sometimes constitutes entire hil- 
 locks ; frequently it interposes it- 
 self in large veins and seams in the 
 clefts of calcareous rocks : it be- 
 longs essentially to alluvial soils. 
 
 PSAMMITES is a term applied to 
 an assemblage of the grains of 
 quartz, schist, felspar, and particles 
 of mica, agglutinated by a variable 
 cement. The varieties of these are 
 very numerous : those which in 
 appearance strongly resemble the 
 free-stones and siliceous breccias 
 belong to the class of rocks whose 
 disaggregation furnishes sand, pro- 
 perly so called. But the psam- 
 mites, which are slaty, of a yellow, 
 red, or brown colour, fine-grained, 
 unctuous to the touch, producing 
 a clayey paste with water, form a 
 distinct species, and one which 
 merits attention. 
 
 These last belong to the primi- 
 tive schistose formations : they do 
 not and cannot exist except in situ : 
 they are found in beds or veins, 
 forming part of the schist of which 
 they are merely a decomposition. 
 
 CLAYS are earthy substances va- 
 riously coloured, fine, soft to the 
 touch, which diffuse in water with 
 facility, forming with it a paste, 
 which, when kneaded to a certain 
 consistency, possesses unctuosity 
 and tenacity, and may be drawn 
 out and kneaded in every direction 
 without separating. The clayey 
 paste, when dried, retains its soli- 
 dity, hardens in the fire, etc. 
 
MOR 
 
 MORTAR. 
 
 MOR 
 
 Clays are essentially composed 
 of silica and alumina : these two 
 substances are adulterated by the 
 presence of the oxide of iron, the 
 carbonates of lime and magnesia, 
 sulphuret of iron, and of vegetable 
 combustible matter partly decom- 
 posed. 
 
 The clays are separated into four 
 classes : viz. the refractory, which 
 resist, without melting, the heat of 
 the porcelain furnaces (140 Wedg- 
 wood) ; the fusible clays ; the ef- 
 fervescing or clayey marls ; and, 
 lastly, the ochrey clays, coloured 
 red or pure yellow by oxide of iron. 
 
 The position of clays is very va- 
 ried : they are found as veins in pri- 
 mitive formations ; in hillocks, on 
 the confines of the primitive chains ; 
 in horizontal beds, or layers, in the 
 secondary formations ; in threads, 
 thin veins, or infiltrations, in chinks 
 and hollows of calcareous masses ; 
 lastly, in volcanic regions, where 
 their formation is attributed to the 
 decomposition of the compact lavas, 
 and perhaps also, with some proba- 
 bility, to miry eruptions. 
 Mortar. Considered as a plastic 
 material, mortar fit for moulding 
 may be made to take every pos- 
 sible form in moulds or shapes. 
 To give it the appearance of stone, 
 it should be made with fine colour- 
 less sand, or rather with fine calca- 
 reous powders derived from hard 
 stones. 
 
 Mortar contained in a mould may 
 be beaten or rammed in the manner 
 of pise, " a mode of building for- 
 merly in use, whereby walls were 
 formed by ramming and beating 
 down earth, clay, etc., between up- 
 right planks," and acquires by 
 that means great compactness ; but 
 an increase of resistance does not 
 always result from this. 
 
 In order that any material be 
 beaten with effect, it is necessary 
 that it should possess a certain de- 
 gree of consistency, which is a mean 
 between complete pulverulence and 
 that state of ductility which con- 
 
 stitutes a firm paste. No compres- 
 sion is possible when the material 
 escapes from under the rammer; 
 and this is still practised by the 
 builders in pise, who never employ 
 any but earth slightly moistened. 
 Mortar may always be prepared in 
 this way, leaving it, after it has been 
 worked in the ordinary manner, to 
 undergo desiccation to a proper 
 extent. 
 
 The successive approximation of 
 the particles of the compressed 
 material to one another neces- 
 sarily determines a foliated struc- 
 ture, which, though it may not 
 be perceived, is nevertheless real. 
 Analogy will lead to the conclusion, 
 that, in every possible case, a body 
 thus formed ought to oppose a 
 greater resistance to a tractile force 
 in proportion as its direction forms 
 a smaller angle with the plane of 
 the laminae ; however, experience 
 shows that this in general does not 
 take place. The following has been 
 determined in this respect : 
 
 1st. Beating has the effect of 
 augmenting the absolute resistance 
 of mortars of rich limes and pure 
 sand in every case, but in an un- 
 equal manner. The greatest re- 
 sistance assumes a direction per- 
 pendicular to the planes of the 
 laminae when the mortars are buried 
 in a damp soil immediately after 
 their fabrication. It remains pa- 
 rallel to these same planes when 
 the mortars have been exposed to 
 the atmospheric influence. 
 
 2nd. The eifect of beating is 
 not constantly useful to mortars of 
 hydraulic or eminently hydraulic 
 limes, and calcareous or quartzose 
 sands or powders, except in the 
 case when these mortars are used 
 under a damp soil. The greatest 
 resistance is then in a direction 
 perpendicular to the planes of these 
 laminae, as with the mortars of rich 
 limes ; but in the air, the superiority 
 of the mortars which have been 
 beaten over those which have not 
 is only exhibited in one direction, 
 
 293 
 
MOR 
 
 MORTAR. 
 
 MOR 
 
 and that is parallel to the plane of 
 the laminae. 
 
 3rd. Beating becomes injurious 
 in every case when the hydrates of 
 the hydraulic or eminently hydrau- 
 lic limes are employed without 
 admixture, and subjected to the 
 influence of a damp soil ; and is 
 favourable to it only in the direc- 
 tion parallel to the lamina when 
 the stuff dries in the air. 
 
 Considered as a plastic sub- 
 stance, the numerous casts which 
 have been moulded, both in the 
 bas-relief and alto-relievo, prove 
 that mortar receives and retains 
 impressions well: their hardness 
 is continually on the increase, and 
 a kind of varnish, with which time 
 covers them, gives them a strong 
 resemblance to stone. 
 
 One problem remains to be 
 solved, viz. to discover a means of 
 hastening the set of mortar with- 
 out injuring its future qualities; 
 and this, in order to avoid being 
 obliged to multiply moulds indefi- 
 nitely for the same casting. This 
 last desideratum appears to be dif- 
 ficult. The natural cements, which 
 harden almost instantly in the air 
 and in the water, when worked up 
 like plaster of Paris, are subject to 
 the inconvenience of being tinged 
 brown. Such as are fabricated 
 artificially, by calcining mixtures 
 of lime and clay free from iron, 
 do not stand the weather. 
 
 Mortar of hydraulic lime may be 
 employed as a plastic substance in 
 a multitude of cases, in which the 
 number of moulds is no inconve- 
 nience. Such is the case in the pre- 
 paration of artificial stones bearing 
 mouldings, vases, or ornaments of 
 any kind susceptible of formation 
 by the rectilinear or circular move- 
 ment of a profile. It is evident 
 that it will then answer to set the 
 mould in a trench, and run the 
 profile along the clayey paste, pre- 
 pared and arranged for that pur- 
 pose. The economy which such 
 a process would introduce into 
 
 ornamental constructions is indeed 
 incredible. 
 
 Mortise, in carpentry, a hole cut in a 
 piece of wood, to receive a corre- 
 sponding projection formed upon 
 another piece. 
 
 Mortise and Tenon. The following 
 rules may be referred to as data 
 for the workman in ordinary prac- 
 tice. 
 
 The tenon, in general, may be 
 taken at about one-third of the 
 thickness of the wood. 
 
 When the mortise and tenon are 
 to lie horizontally, as the juncture 
 will thus be unsupported, the tenon 
 should not be more than one-fifth 
 of the thickness of the stuff, in 
 order that the strain on the upper 
 surface of the tenoned piece may 
 not split oflf the under-cheek of the 
 mortise. 
 
 When the piece that is tenoned 
 is not to pass the end of the mor- 
 tised piece, the tenon should be 
 reduced one-third or one-fourth of 
 its breadth, to prevent the necessity 
 of opening one side of the tenon. 
 As there is always some danger of 
 splitting the end of the piece in 
 which the mortise is made, the end 
 beyond the mortise should, as often 
 as possible, be made considerably 
 longer than it is intended to re- 
 main ; so that the tenon may be 
 driven tightly in, and the super- 
 fluous wood cut off afterwards. 
 
 But the above regulations may 
 be varied, according as the tenoned 
 or mortised piece is weaker or 
 stronger. 
 
 The labour of making deep mor- 
 tises, in hard wood, may be lessened, 
 by first boring a number of holes 
 with the auger in the part to be 
 mortised, as the compartments be- 
 tween may then more easily be cut 
 away by the chisel. 
 
 Before employing the saw to cut 
 the shoulder of a tenon in neat 
 work, if the line of its entrance be 
 correctly determined by nicking 
 the place with a paring chisel, 
 there will be no danger of the 
 
 294 
 
10S 
 
 MOULDINGS. 
 
 MOU 
 
 wood being torn at the edges by 
 the saw. 
 
 As the neatness and durability 
 of a juncture depend entirely on 
 the sides of the mortise coming 
 exactly in contact with the sides of 
 the tenon, and as this is not easily 
 performed when a mortise is to pass 
 entirely through a piece of stuff, 
 the space allotted for it should be 
 first correctly gauged on both sides. 
 One half is then to be cut from 
 one side, and the other half from 
 the opposite side ; and as any ir- 
 regularities which may arise from 
 an error in the direction of the 
 chisel will thus be confined to the 
 middle of the mortise, they will be 
 of very little hindrance to the 
 exact fitting of the sides of the 
 mortise and tenon. Moreover, as 
 the tenon is expanded by wedges 
 after it is driven in, the sides of 
 the mortise may, in a small degree, 
 be inclined towards each other, 
 near the shoulders of the tenon. 
 
 M-roof, a roof formed by the junction 
 of two common roofs with a vallum 
 between them. 
 
 Mosaic (The) books, and the other 
 historical books of the Old Testa- 
 ment, are not intended to present, 
 and do not present, a picture of 
 human society, or of our nature 
 drawn at large. Their aim is to 
 exhibit it in one master relation, 
 and to do this with effect, they do 
 it, to a great extent, exclusively. 
 The Homeric materials for exhibit- 
 ing that relation are different in 
 kind as well as in degree ; but as 
 they paint, and paint to the very 
 life, the whole range of our nature 
 and the entire circle of human 
 action and experience, at an epoch 
 much more nearly analogous to the 
 patriarchal time than to any later 
 age, the poems of Homer may be 
 received in the philosophy of hu- 
 man nature, as the complement of 
 the earliest portion of the sacred 
 records. (Gladstone.) 
 
 Mosaic-work, the art of picturing 
 with small pebbles and shells of 
 
 various colours, pieces of glass, 
 marble, etc., cemented on a ground 
 of stucco. 
 
 Mosque, a Mohammedan temple. 
 
 Motif, that which suggests a hint 
 or idea to an artist ; also the hint 
 itself. 
 
 Motion. The cross-head, cross-head 
 guides, and blocks, in a locomotive 
 engine, taken as a whole, are called 
 " the motion." 
 
 Motion (laws of). A body must con- 
 tinue for ever in a state of rest, or 
 in a state of uniform and rectili- 
 neal motion, if it be not disturbed 
 by the action of some external 
 cause. The alteration of motion 
 produced in a body by the action 
 of any external force is always 
 proportional to that force, and in 
 the direction of the right line in 
 which it acts. The action and re- 
 action of bodies on one another 
 are equal, and are exerted in op- 
 posite directions. 
 
 Motion of bodies on inclined planes. 
 The force of an inclined plane 
 bears the same proportion to the 
 force of gravity as the height of 
 the plane bears to its length ; that 
 is, the force which accelerates the 
 motion of a body down an inclined 
 plane, is that fractional part of the 
 force of gravity which is repre- 
 sented by the height of the plane 
 divided by its length. 
 
 Mould, the model or pattern used by 
 workmen as a guide in working 
 mouldings and ornaments, in the 
 casting of metal, and models of 
 machinery. 
 
 Mouldings, a term applied to all the 
 varieties of outline or contour 
 given to the angles of the various 
 subordinate parts and features of 
 buildings, whether projections or 
 cavities, such as cornices, capitals, 
 bases, door or window jambs, and 
 heads, etc. There are eight sorts 
 of regular mouldings, viz. the 
 Ovolo, the Talon, the Cyma, the 
 Cavetto, the Torus, the Astragal, 
 the Scotia, and the Fillet. These 
 mouldings are not to be used at 
 
 295 
 
MOU 
 
 MOULDINGS. 
 
 MOU 
 
 hazard, each having certain /itu- 
 ations adapted to its reception, to 
 which it must always be applied. 
 Thus the ovolo and talon, from 
 their peculiar form, seem intended 
 to support other important mould- 
 ings or members ; the cyma and 
 cavetto, being of weaker contour, 
 should only be used for the cover 
 or shelter of other parts ; the torus 
 and astragal, bearing a resemblance 
 to a rope, appear calculated to bind 
 and fortify the parts to which they 
 are applied; the use of the fillet 
 and scotia is to separate one mould- 
 ing from another, and to give a 
 variety to the general profile. The 
 
 ovolo and talon are mostly placed 
 in situations above the level of the 
 eye; when below it, they should 
 only be applied as crowning mem- 
 bers. The place for the scotia is 
 universally below the level of the 
 eye. When the fillet is very wide, 
 and used under the cyma of a cor- 
 nice, it is termed a corona ; if un- 
 der a corona* it is called a band. 
 
 The curved contours of mould- 
 ings are portions of either circles 
 or ellipses. 
 
 The principal mouldings, and the 
 difference of their profiles in the 
 Grecian and Roman styles, are here 
 exhibited. 
 
 ROMAN. 
 
 Echinus or 
 Ovolo. 
 
 Cyma Recta. 
 
 Cyma Re- 
 versa. 
 
 Scotia. 
 
 Torus. I 
 
 Moulding, the process of forming a 
 cavity in sand or loam, in order to 
 give its form to metal which is ap- 
 plied in a fluid state ; an ornamen- 
 tal cavity in wood, stone, or other 
 suitable material. 
 
 Mountain-blue. A very beautiful sub- 
 stance of this kind, a carbonate of 
 copper, both blue and green, is 
 found in Cumberland. None of 
 these blues of copper are, however, 
 durable ; used in oil, they become 
 
 296 
 
IOU 
 
 MUSIC. 
 
 MUS 
 
 green, -and, as pigments, are pre- 
 cisely of the character of verditers. 
 
 fountain-green is a native carbonate 
 of copper, combined with a white 
 earth, and often striated with veins 
 of mountain-blue, to which it bears 
 the same relation that green ver- 
 diter does to blue verditer; nor 
 does it differ from these and other 
 copper-greens in any property es- 
 sential to the painter. 
 
 M. S., an abbreviation commonly used 
 on tomb-stones or monumental 
 tablets for the Latin words Me- 
 moriae Sacrum, ' Sacred to the Me- 
 mory': the letters I.H.S. are often 
 similarly applied in sacred edifices, 
 for Jesus Hominum Salvator, 
 ' Jesus the Saviour of Men.' 
 
 \fud-holes, the covered openings in 
 the bottom of a boiler for discharg- 
 ing the dirt and sediment. 
 
 \fud-plugs, in locomotive engines 
 tapered screw-plugs fitted into con- 
 venient parts of the boiler, to admit 
 of its being washed out by these 
 plug-holes when necessary. 
 
 Mulberry-tree, a wood of great va- 
 riety, principally from Rio Janeiro, 
 and very suitable for furniture. 
 
 Mullion, the division between the 
 lights of windows, screens, etc., in 
 Gothic architecture : the styles or 
 upright divisions in wainscoting 
 are also sometimes called mullions. 
 
 Mule-jenny, a machine used in the 
 manufacture of cotton thread. 
 
 Mun (Cornish), any fusible metal. 
 
 MundicJc, an exceedingly ponderous 
 mineral, whitish, beautiful and 
 shining, but brittle. It is abundant 
 in Cornish and Irish mines. 
 
 Muniment -house, a strong, properly 
 fire-proof apartment in public or 
 private buildings, for the preser- 
 vation of charters, deeds, seals, 
 etc. 
 
 Munnions, pieces that part the lights 
 in a ship's stern and quarter-gallery. 
 
 Munnions, in house-building, upright 
 posts that divide the lights in a 
 window-frame. 
 
 Mummy, or Egyptian-brown, is a 
 bituminous substance, combined 
 
 297 
 
 with animal remains brought from 
 the catacombs of Egypt, -where 
 liquid bitumen was employed three 
 thousand years ago in embalming, 
 in which office it has been com- 
 bined, by a slow chemical change, 
 during so many ages, with sub- 
 stances which give it a more solid 
 and lasting texture than simple 
 asphaltum ; but in this respect it 
 varies exceedingly. 
 
 Mural, pertaining to a wall ; a monu- 
 mental tablet affixed to a wall is a 
 mural monument. 
 
 Murometer, an instrument to measure 
 small spaces. 
 
 Murus, the wall of a Greek city, in 
 contradistinction to Paries, the wall 
 of a house, andMaceria, a boundary 
 wall. 
 
 Music. This word is derived from 
 the Latin musica, and this again 
 from the Greek adjective mousikos, 
 which signifies, of or belonging to 
 the Muses. As a substantive, the 
 word mousikos, or in Latin musicus, 
 a musician, means also a poet or 
 an orator : and in the feminine 
 gender signifies the liberal arts, but 
 especially music, poetry, and elo- 
 quence. The ancients, therefore, 
 understood by music far more than 
 has been attributed to it for some 
 ages past. Music is now considered 
 as the language of agreeable sounds, 
 and is both a science and an art. 
 As a science, it teaches the theory 
 of musical sounds, their production 
 by the vibrations of the air, the 
 ratio of these vibrations, and also 
 their times; likewise the various 
 phenomena connected with musical 
 sounds, the causes of discords, beats, 
 etc., as well as the lengths of mu- 
 sical strings and 1 pipes. The ma- 
 thematical theory of music is part 
 of the science of acoustics, or 
 phonics, and is therefore one of the 
 high mechanical sciences. As an 
 art, music teaches the practical use 
 of the science ; the scales or gamuts 
 of sounds in a fixed succession, at 
 fixed intervals from each other ; the 
 permutations of their sounds; form- 
 
MUS 
 
 NAOS. 
 
 NAP 
 
 ing an immense variety of melqdies. 
 It teaches also the combination of 
 these sounds according to certain 
 received laws, forming thereby the 
 most agreeable sensations on the 
 ear, by producing a great variety of 
 chords, composed of concordant 
 sounds alone, or of a judicious ad- 
 mixture of concordant and dissonal 
 sounds. Practical music teaches 
 also the use and performance of the 
 several instruments of music, as 
 also their peculiar functions; and 
 herein is embraced thehuman voice, 
 the most perfect and beautiful of 
 all musical instruments. Music, 
 therefore, is divided into two grand 
 parts, viz. theoretical or scientific, 
 and practical ; the former treating 
 of the purely philosophical branch 
 mathematically, the latter being 
 confined solely to the production of 
 musical compositions, and their per- 
 formance. Practical music consists 
 of several species, the highest of 
 which is the ecclesiastical ; then 
 follow the oratorio, opera, military, 
 chamber,and ball-room species; and 
 
 NAILS, used in building, are small 
 metallic spikes serving to bind or 
 fasten the parts together. There 
 are several kinds of nails, called by 
 numerous names. In the middle 
 ages, nails were frequently used 
 much ornamented, of which there 
 are several very beautiful existing 
 specimens, particularly in church 
 doors and the gates of large man- 
 sions. 
 
 Naked, of a column or pilaster, the 
 surface of the shaft where the 
 mouldings are supposed to project. 
 
 Naked, of a wall, the remote face 
 whence the projectures take their 
 rise. It is generally a plain sur- 
 face, and when the plan is circular, 
 the naked is the surface of a cy- 
 linder, with its axis perpendicular 
 to the horizon. 
 
 Naked flooring, in carpentry, the 
 whole assemblage or contignation 
 
 298 
 
 is divided into vocal and instru- 
 mental music, each of these being 
 variously subdivided. 
 
 Musnud, in Persia, a throne, or chair 
 of state. 
 
 Mustaib, a wood from the Brazils, 
 inferior to rosewood, but harder ; ; 
 used at Sheffield for the handles of 
 glaziers' and other knives, etc. 
 
 Mutule, a projecting block worked 
 under the corona of the Doric cor- 
 nice, in the same situation as the 
 modillions in the Corinthian and; 
 Composite orders ; it is often made 
 to slope downward towards the most ' 
 prominent part, and has usually a 
 number of small guttae or drops, 
 worked on the under side. 
 
 Myribhery, the Saxon name for a nun- 
 nery : nuns were sometimes called 
 Mynchies. 
 
 Myoparo, a small piratical craft, em- 
 ployed by the Saxon corsairs. 
 
 Myriad, the number of 10,000 ; pro- 
 verbially any great number. 
 
 Myriametre, a French measure of 
 10,000 metres. 
 
 of timber-work for supporting the 
 boarding of a floor on which to 
 walk. Naked flooring consists of 
 a row of parallel joists, called floor- 
 joists. 
 
 Naos, the chamber or enclosed apart- 
 ment of a Greek temple. The part 
 of the temple which stood before 
 the naos, comprehended between 
 the wall and the columns of the 
 portico, was called the pronaos ; 
 while the corresponding part be- 
 hind was called the posticum. 
 
 Naples yellow is a compound of the 
 oxides of lead and antimony, an- 
 ciently prepared at Naples under 
 the name of Grallolina ; it is sup- 
 posed also to have been a native 
 production of Vesuvius and other 
 volcanoes, and is a pigment of de- 
 servedly considerable reputation. 
 It is not so vivid a colour as patent 
 yellow and turbith mineral, but i 8 
 
N T AP 
 
 NASMYTH'S MACHINES. 
 
 NAT 
 
 variously of a pleasing, light, warm 
 golden-yellow tint. Like most 
 other yellows, it is opaque, and 
 in this sense is of good body. It 
 is not changed by the light of the 
 sun, and may be used safely in oil 
 or varnish, under the same man- 
 agement as the whites of lead ; 
 but like these latter pigments also, 
 it is likely to change even to black- 
 ness by damp and impure air when 
 used as a water-colour, or unpro- 
 tected by oil or varnish. 
 
 Naphtha, a species of mineral oil or 
 fluid bitumen, now commonly used 
 for lamps. 
 
 Narthex, a division in the early 
 Christian churches in which the 
 catechisms were said, and peni- 
 tents admitted ; it was near the 
 entrance, and separated 'from the 
 rest of the church by a railing or 
 screen. 
 
 Nasmyttts patent direct -action steam- 
 hammer is employed instead of the 
 old helves or lift-hammers, and is 
 worked by a connected high-pres- 
 sure steam engine, which raises the 
 hammer to any required height 
 within its vertical range of motion, 
 and in which it is guided by two 
 planed guides. On the escape of 
 the steam, when the valve of the 
 cylinder is opened, the hammer 
 falls on the work that lies on the 
 anvil with the full force due to 
 gravity, without scarcely any loss 
 from friction. The instant the 
 hammer has given its blow, the 
 steam is again let in under the 
 piston, and the same action is re- 
 peated with ease and rapidity. 
 
 Nasmyth's steam pile-driving engine. 
 There are two grand or important 
 features of novelty in this pile- 
 driving engine, compared with all 
 former contrivances for the like 
 purpose. In the first place, by the 
 employment of the steam-hammer 
 action, the steam is made to act 
 direct in raising up and letting fall 
 the hammer, or monkey, without 
 the intervention of any rotatory mo- 
 tion ; while, in the second place, 
 
 299 
 
 another grand feature consists in 
 the employment of the pile about 
 to be driven, or raised up and 
 planted in its situation by the ma- 
 chine, by means of a windlass 
 worked by a small detached steam 
 engine. 
 
 Some conception of the rapidity 
 with which piles are driven by this 
 machine may be formed, when it 
 is stated that a pile measuring 60 
 feet in length, and 14 inches 
 square, can be driven 45 feet into 
 stifFsoil, down to the rock below, in 
 four minutes ; and such is the good 
 effect resulting from the blows 
 being given by a great mass of 
 30 cwt. striking quickly but with 
 small velocity of actual impact, that 
 the head of the pile requires no 
 hoop, and presents, after being 
 driven, a neater appearance than it 
 had when it was first placed under 
 the hammer. 
 
 Natural beds of stone are the surfaces 
 from which the laminae are sepa- 
 rated. It is all-important for the 
 duration of stone walls, that the 
 laminae should be placed perpendi- 
 cular to the face of the work, and 
 parallel to the horizon. 
 
 Natural Philosophy takes an exten- 
 sive range, -embracing the study of 
 the collection of created beings 
 and objects, and of those laws by 
 which they are governed, all of 
 them expressed in the term Nature. 
 Natural objects are separated into 
 two grand classes, the organic and 
 inorganic ; the former being dis- 
 tinguished by vital power or life : 
 organic bodies admit of a marked 
 distinction into animals and plants ; 
 the science of Zoology describing 
 and classifying the one, and that of 
 Botany the other. These sciences 
 admit of many subdivisions, and 
 collectively with Mineralogy, that 
 of Natural History. 
 
 1. Geology, the science which has 
 for its object the observation and 
 description of the structure of the 
 external crust of the globe ; Mine- 
 ralogy taking account only of the 
 
NAT 
 
 NAVE. 
 
 NBA 
 
 separate items of which the earth's 
 crust is composed. 2. Chemistry, 
 which may be regarded as atomic 
 anatomy, its object being to de- 
 compose bodies, to study the pro- 
 perties of their elements, and the 
 laws of combination. 3. Physics, 
 or Natural Philosophy, which con- 
 siders the general properties of all 
 bodies. Natural philosophy is 
 again subdivided into many dis- 
 tinct sciences. The mutual action 
 of forces and masses of matter 
 produces in the latter either equi- 
 librium or motion, and hence arise 
 those two divisions of sciences, 
 called Statics and Dynamics, which 
 are again divided into Stereo-statics 
 and Stereo-dynamics, as applied to 
 solids ; Hydrostatics and Hydro- 
 dynamics, as applied to liquids ; 
 Electro-statics and Electro-dyna- 
 mics, as applied to Electricity. 
 The application of statics and dy- 
 namics to air and other gaseous 
 fluids is called Pneumatics. The 
 application of dynamics to the arts 
 of life has led to the composition 
 and arrangement of the various 
 machines for assisting the labour 
 of man : this branch is called Me- 
 chanics. The construction and per- 
 formance of the various machines 
 to raise water, or which are dri- 
 ven by the motion of that fluid, 
 belong to hydrodynamics, while 
 the construction of works depend- 
 ing on the equilibrium of liquids 
 belongs to hydrostatics. Those 
 machines which are driven by the 
 wind depend on the application of 
 pneumatics ; and all the varied 
 phenomena of the atmosphere 
 arising from the action of heat, 
 light, electricity, and moisture, 
 form the science of Meteorology. 
 The phenomena of heat and elec- 
 tricity also form separate sciences ; 
 the latter admitting of five divi- 
 sions, viz. electricity, magnetism, 
 galvanism or voltaic electricity, 
 thermo-electricity, and animal 
 electricity. The phenomena of 
 light, although included in the 
 
 term Optics, are varied; namely, 
 perspective, catoptrics, dioptrics, 
 chromatics, physical optics, and 
 polarization; to which may be 
 added actino-chemistry. 
 
 Naumachia, among the Greeks, a 
 sea-fight; a spectacle. The term} 
 was also applied to a circus encom-j 
 passed with seats and porticoes, 1 
 the pit of which, serving as an 
 arena, was filled with water by 
 means of pipes, for the exhibition 
 of sea-fights. 
 
 Naupegus, a shipwright. 
 
 Nautical, pertaining to ships or sailors. 
 
 Naval Architecture, the art of de- 
 signing and constructing ships and 
 vessels for the purposes of naviga- 
 tion. 
 
 Navale, a ship-dock or dockyard. 
 
 Navalia, ship-building docks at Rome, 
 where also ships were laid up and 
 refitted. 
 
 Navarchus, among the ancients, the 
 name of a commander or admiral 
 of a fleet. 
 
 Nave, the body of a church west of 
 the choir, in which the general 
 congregation assemble. In large 
 buildings it consists of a central 
 division, with two or more aisles; 
 and there are frequently, in foreign 
 structures, several small chapels on 
 the sides beyond the aisles. In 
 mechanics, the central part of a 
 wheel. 
 
 Navel-hoods, in ship-building, pieces 
 of plank, or thick stuff, wrought 
 above and below the hawse-holes. 
 
 Navis, in church furniture, a metal 
 dish or vessel to contain frankin- 
 cense. 
 
 Neap, low, decrescent ; a term applied 
 to the tides which happen when 
 the moon is in the middle of her 
 second and fourth quarters. The 
 highest spring-tide is three days 
 after the full or change ; the lowest 
 neap-tide is four days before the 
 full or change. 
 
 Neapolitan School of painting, which 
 possesses indisputable proofs of 
 having in ancient times ranked 
 among the first in Italy ; as in no 
 
 300 
 
NBA 
 
 NEAPOLITAN SCHOOL. 
 
 NER 
 
 part of that country do the re- 
 mains of antiquity evince a more 
 refined taste, nowhere do we find 
 mosaics executed with more ele- 
 gance, nor anything more beautiful 
 than the subterranean chambers 
 which are ornamented with his- 
 torical designs arid grotesques. 
 
 At the restoration of art, it had 
 made little progress in Naples and 
 her territories before Zingaro's 
 time. His name was Antonio So- 
 lario, originally a smith, and com- 
 monly called lo Zingaro. His his- 
 tory has something romantic in it, 
 like that of Quintin Matsys. 
 
 The most celebrated work of 
 Zingaro's was in the choir of S. 
 Severino, in fresco, representing in 
 several compartments the life St. 
 Benedict. He left numerous pic- j 
 tures, and Madonnas of a beautiful \ 
 form, in various churches of Naples, ! 
 in that of S. Domenico Maggiore, 
 where he painted a Dead Christ, 
 and in that of S. Pier Martire, where ! 
 he represented a S. Vincenzio. 
 
 Two eminent artists of the Nea- 
 politan School were Matteo da 
 Siena and Antonella da Messina. I 
 The latter is a name so illustrious i 
 in the history of art, that he claims 
 notice in the Sienese, Neapolitan, 
 and Venetian Schools. 
 
 It has already been observed j 
 that at the commencement of the j 
 sixteenth century, the art of paint- 
 ing seemed in every country to have 
 attained to maturity, and that every 
 school assumed its own peculiar 
 character. Naples however did 
 not possess a manner so decided as 
 that of other schools in Italy. 
 
 A writer has observed that no 
 part of Italy could boast of so many 
 native artists. 
 
 Their rapidity of execution was 
 another effect of their genius, a 
 quality which has been alike praised 
 by the ancients and the moderns, 
 when combined with other more 
 requisite gifts of genius. But this 
 despatch in general excludes cor- 
 rect design, which from that cause 
 
 is seldom found in that school. Nor 
 do we find that it paid much at- 
 tention to ideal perfection, as most 
 of its professors, following the prac- 
 tice of the naturalists, selected the 
 character of their heads and the 
 attributes of their figures from 
 common life; some with more, 
 and others with less discrimina- 
 tion. With regard to colour this 
 school changed its principles in con- 
 formity to the taste of the times. 
 
 The modern Neapolitan School 
 is founded on the schools of Raffa- 
 ello and Michelangiolo. 
 
 The chief names are Andrea Sab- 
 batini, Polidoro Caravaggio, Marco 
 da Siena, Corenzio, Ribera Carrac- 
 ciolo, Luca Giordano, and Solimene. 
 Nebule moulding, an heraldic term. 
 In architecture, an ornament of the 
 zigzag form, but without angles : 
 it is chiefly found in the remains of 
 Saxon architecture, in ' the archi- 
 volts of doors and windows. 
 Neck of a capital, the space between 
 the astragal on the shaft and the 
 annulet of the capital in the Grecian- 
 Doric order. 
 
 Neck-mould, in architecture, a small 
 
 convex moulding surrounding a 
 
 column at the junction of the shaft 
 
 and capital. 
 
 Necrology, an obituary formerly kept 
 
 in churches and monasteries. 
 Needle, or Nail, in mining, a long 
 taper piece of copper or iron, with 
 a copper point ; used when stamp- 
 ing the hole for blasting, to make 
 by its insertion an aperture for a 
 fusee or train. 
 Needlework, a term anciently used 
 for the framework of timber and 
 plaster in old houses. 
 Neo, a Greek term, to spin or twist a 
 number of separate fibres of woo] 
 or flax into a single thread. 
 Ne plus ultra (Latin), the extreme 
 
 of anything. 
 
 Nervures, nerves or branches, a term 
 applied by Prof. Willis, of Cam- 
 bridge, to the ribs of a vaulted roof 
 which bound the sides of any 
 groined compartment. 
 
 301 
 
NET 
 
 NICHE. 
 
 NON 
 
 Net, or Neat, in commerce, that whjch 
 is pure and unadulterated; the 
 weight of any package after the 
 tare has been deducted : some- 
 times, but improperly, written nett. 
 
 Newel, the central column round 
 which the steps of a circular stair- 
 case wind ; the principal post at 
 the angles and foot of a stair- 
 case. In the Tudor and Elizabe- 
 than residences very beautiful ex- 
 amples exist, adding much to the 
 beauty of the staircase. 
 
 Niche, in architecture, a cavity or 
 hollow place in the thickness of a 
 wall, in which to place a figure, a 
 statue, vase, or ornament. Niches 
 are made to partake of all the seg- 
 ments under a semicircle : they are 
 sometimes at an equal distance 
 from the front, and parallel or 
 square on the back with the front 
 line, in which case they are called 
 square recesses, or square niches. 
 Occasionally small pediments were 
 formed over them, supported on 
 consoles, or small columns or pi- 
 lasters placed at the sides of the 
 niches. Anciently they were used 
 in ecclesiastical buildings for sta- 
 tues and shallow square recesses. 
 The ruins of Palmyra exhibit niches 
 of various kinds. Within the por- 
 tico of the temple of the Sun there 
 are two niches, etc. 
 
 Niche, angular, one formed in the 
 corner of a building. 
 
 Niche, in carpentry, the wood-work 
 to be lathed-over for plastering. 
 The usual constructions of niches 
 in carpentry are those with cylin- 
 drical backs and spherical heads, 
 called cylindro-spheric niches, the 
 execution of which depends upon 
 the principles of spheric sections. 
 
 Niche, (/round, that which, instead of 
 bearing on a massive base or dado, 
 has its rise from the ground, as 
 the niches of the portico of the 
 Pantheon at Rome : their ordinary 
 proportion is, two diameters in 
 height, and one in width. Round 
 or square niches are also formed. 
 
 Nigged ashlar, stone hewn with a pick 
 
 302 
 
 or pointed hammer, instead of a 
 chisel ; used principally at Aber- 
 deen for the hewing of the hard 
 granite. 
 
 Nitrate of lime, nitric acid in com- 
 bination with lime for a base, 
 abounding in the mortar of old 
 buildings. 
 
 Nitrates, compounds, or salts, formed 
 by the combination of nitric acid 
 with alkalies, earths, and metallic 
 oxides. 
 
 Nitre, common saltpetre ; in chemis- 
 try, nitrate of potash. 
 
 Nodus, anciently, in our cathedrals, a 
 knot, key-stone, or boss. 
 
 Nog, in ship-building, a treenail driven 
 through the heel of the shores 
 which support a ship on the slip. 
 
 Nogs, blocks of wood cut to the form 
 and size of bricks, and inserted in 
 the nterior walls of apartments as 
 holds for the joinery. 
 
 Nogs or Nays, in mining, square 
 pieces of wood piled on each other 
 to support the roof of a mine. 
 
 Nagging, a kind of brickwork carried 
 up in panels between quarters. 
 
 Nogging-pieces are horizontal boards 
 placed in brick-nogging, nailed to 
 the quarters in order to strengthen 
 the brickwork. 
 
 Nomades, in antiquity, wandering, 
 rude, or savage tribes. 
 
 Nomenclature, the art of naming; a 
 vocabulary or dictionary of techni- 
 cal language peculiar to any art or 
 science. 
 
 Nonagon, a figure of nine sides and 
 of as many angles. 
 
 Non-condensing Engines are those 
 made without that part of the ma- 
 chine called a condenser, and with- 
 out those contrivances essential to 
 the ordinary construction of en- 
 gines that condense the vapour into 
 fluid. In non-condensing engines 
 the steam escapes into the atmo- 
 sphere, after having acted upon the 
 piston. The effect is measured by 
 the excess of the pressure of the 
 steam upon the piston, less the 
 friction of the engine above the 
 pressure of the atmosphere. 
 
NON 
 
 NORMAN ARCHITECTURE. 
 
 NOR 
 
 Non-cdflductors, substances through 
 which the electric fluid passes with 
 considerable difficulty or not at all; 
 such as glass, resin, sulphur, silk, 
 hair, wool, the air, etc. ; but these 
 become electric by friction. 
 Nones, in the Roman calendar, the 
 fifth day of January,February,April, 
 June, August, September, Novem- 
 ber, December ; and the seventh 
 of March, May, July, and October. 
 
 Noria, an hydraulic machine, com- 
 mon in Spain for raising water. The 
 engine consists of a vertical wheel 
 of 20 feet diameter, on the circum- 
 ference of which are fixed buckets, 
 for the purpose of raising water out 
 of wells, etc., communicating with 
 a canal below,and emptying it into a 
 reservoir above, placed by the side 
 of the wheel. The buckets have a 
 lateral orifice, to receive and dis- 
 charge the water. The axis of the 
 wheel is embraced by four small 
 beams, crossing each other at right 
 angles, tapering at the extremities, 
 and forming eight little arms. This 
 wheel is near the centre of the 
 horse-walk, contiguous to the ver- 
 tical axis, into the top of which the 
 top beam is fixed: but near the 
 bottom it is embraced by four little 
 beams, forming eight arms similar 
 to those above described, on the 
 axis of the water-wheel. In the 
 movement of the horse or mule, 
 these horizontal arms, acting on 
 cogs, take hold, each in succession, 
 of those arms which are fixer' on 
 the axis of the water-wheel, and 
 keep it in rotation. 
 
 Norma, a square for measuring right 
 angles, used by carpenters, masons, 
 and other artificers, to make their 
 work rectangular. 
 
 Normal line, in geometry, a phrase 
 used for a perpendicular line. 
 
 Norman Architecture. In Normandy, 
 in the tenth century, when the 
 Normans occupied Neustria, the 
 churches in other parts of France 
 were in imitation of the Roman 
 style. The plan of the buildings 
 came from Rome, and the round 
 
 303 
 
 arches, the pillars, and the mould- 
 ings, which were employed in their 
 construction, had the same origin. 
 But the corrupt taste of a less 
 civilized people covered the capitals 
 and the portals with a crowd of 
 such appalling images as a wild 
 fancy was likely to suggest, and a 
 rude hand to portray. 
 
 The Normans, adopting the 
 habitual plan and the established 
 style, rejected the meretricious ac- 
 cessories, and resolved to trust for 
 success to the two great principles 
 of size and elevation. The oldest 
 of the Norman churches are the 
 plainest, but even these aspire to 
 dimensions which could not fail to 
 command admiration. Their cha- 
 racter is severe but sublime. At 
 the same time, the Normans had 
 the boldness to insist upon an ad- 
 dition to their churches, which is 
 admitted to be the grandest fea- 
 ture and the chief ornament of ec- 
 clesiastical buildings the central 
 tower. Towers had, fortunately, 
 become an integral part of churches 
 before the Normans began to build 
 in Neustria, but the few towers 
 which at that time existed in other 
 parts of France only adorned the 
 western end. Size, elevation, sim- 
 plicity, and strength, together with 
 the central tower, are the archi- 
 tectural peculiarities to which the 
 Normans, as contradistinguished 
 from the Franks, possess unde- 
 niable claims. 
 
 Norman workmanship was, at 
 first, remarkable onlyfor its solidity. 
 The walls were often built of rubble, 
 faced with small squared stones, 
 a manner of building which had 
 been copied from the works which 
 the Romans had left behind them 
 in France. The pillars were, of 
 course, composed of larger blocks. 
 By degrees, and in buildings of 
 importance, larger blocks were em- 
 ployed in the walls ; but the joints 
 were wide, and the mortar was 
 coarse. In the time of William 
 the Conqueror, greater neatness 
 
 o2 
 
NOR 
 
 NORMAN ARCHITECTURE. 
 
 NOR 
 
 was accomplished ; the stones were 
 squared, and the courses regular ; 
 but the joints were still rather 
 wide, and the mortar unsifted. 
 
 Another mode of construction 
 was with long, narrow stones, 
 which were placed, not in hori- 
 zontal courses, but alternately in- 
 clined to the right and left, this, 
 from the appearance it presented, 
 was called the herring-bone fashion. 
 It did not remain in use much 
 after the eleventh century. 
 
 The Norman walls were of great 
 thickness, and were filled up with 
 small stones, amongst which mortar 
 was poured in hot. This was called 
 grouting ; and in time the whole 
 mass so hardened together as to ac- 
 quire the consistence and strength 
 of a solid rock. Such walls stood 
 in no need of buttresses, through 
 the means of which more advanced 
 science afterwards obtained an equal 
 amount of power at less labour and 
 less expense. Buttresses, however, 
 appear on the exterior of early Nor- 
 man buildings, but seem to have 
 been introduced only to relieve the 
 baldness of the surface. They pro- 
 ject so slightly that they can add 
 but little support. In early Nor- 
 man buildings the buttresses never 
 rise above the cornice. 
 
 The plan of the early Norman 
 churches is always that of the 
 basilica, with a semicircular recess 
 at the end, which recess formed 
 the choir. The larger churches 
 have transepts and side aisles which 
 are divided from the naves by ar- 
 cades. The small churches have 
 often neither side aisles nor tran- 
 septs. The arches of the nave 
 either rest on piers, to which half 
 pillars are attached, or on single 
 pillars, but hardly ever on those 
 huge cylindrical piers which are 
 commonly seen in the Norman 
 churches of England. Indeed, the 
 thick cylindrical piers of England 
 are scarcely to be met with in all 
 France, except in one or two crypts, 
 where the known superincumbent 
 
 weight justifies the prefefence of 
 strength to beauty. 
 
 In the churches of France, single 
 pillars preceded piers ; the exact 
 reverse of what might have been 
 expected, were it not recollected to 
 what an extent and degree France 
 had become Roman, previous to 
 the inroad of the Northern con- 
 querors. The pillars have always 
 capitals, which, at first, were per- 
 fectly plain ; but, from the begin- 
 ning of the eleventh century, were 
 enriched with different kinds of 
 foliage, to a certain degree depart- 
 ing from, but still seeking to imi- 
 tate, the Roman models. The half- 
 pillars, which are attached to the 
 ends of the piers, are always set 
 back in recesses, or sinks ; the same 
 is the case with the small pillars on 
 the outside of the windows, as also 
 with those of the portals. This is 
 a characteristic difference between 
 the Norman style and the Roman, 
 the Norman pillars are recessed, 
 the Roman project. 
 
 The windows are always round- 
 headed and undivided, and, exter- 
 nally, have on each side a small 
 recessed pillar, which supports an 
 impost and moulding. 
 
 In the gable, over the entrance 
 door of churches, a small circular 
 window is sometimes introduced. 
 
 The windows of castles and of 
 domestic buildings are usually di- 
 vided by a single shaft. 
 
 The portals are round-headed, 
 and were gradually enriched by an 
 increasing number of semicircular 
 mouldings. The most common 
 mouldings are the billet, the nail- 
 head, the chevron, the zigzag or 
 embattled frette, hatchet, nebule, 
 star, rope, beak-head, dog-tooth, 
 and, occasionally, different sorts of 
 foliage, as the vine, the bay, the 
 ivy. etc. (See Frontispiece.} 
 
 The external cornice, under the 
 eaves of churches, was sometimes 
 a moulding describing a series of 
 semicircles, under a projecting 
 course, and sometimes a series of 
 
 304 
 
NOR 
 
 ANGLO-NORMAN ARCHITECTURE. 
 
 NOR 
 
 blocks. The ornamented corbels, 
 on the exterior of churches, were 
 adopted by the Normans before 
 imagery was admitted into the in- 
 terior of the edifice. 
 
 The roofs of the early Norman 
 churches were of wood, except the 
 part over the semicircular chancel, 
 which from the first was vaulted 
 with stone. The side aisles were 
 also vaulted with stone ; as were, 
 sometimes, the comparatively small 
 naves of village churches. The 
 vaulting was composed either of 
 small stones let into a bed of mor- 
 tar or of tufa, or of a light calca- 
 reous stone, which is found in many 
 parts of Normandy. The most 
 ancient vaulting is without ribs, 
 and the most ancient ribs are with- 
 out mouldings. % 
 
 The dome vaulting over the side 
 aisles of the abbey church at Bernay 
 is the only specimen of the kind in 
 Normandy. 
 
 The first and purest Norman 
 style prevailed till the latter part 
 of the reign of William the Con- 
 queror, from the early part of the 
 tenth till nearly the end of the 
 eleventh century. 
 
 The abbey church of Bernay, 
 begun in the first half of the 
 eleventh century, is the oldest 
 Norman building of any conse- 
 quence which remains in its pri- 
 mitive form. The architecture of 
 the interior is plain to baldness, 
 but the dimensions are impos : ng. 
 
 The abbey churches of Jumieges 
 and Cerisy were begun in the first 
 half of the eleventh century. The 
 Norman portions of the cathedral, 
 and of the church of St. Taurin,at 
 Evreux, as also of the church of 
 Mont St. Michel, belong to the 
 same period. 
 
 St. Georges de Boscherville, and 
 the two great churches at Caen, 
 are splendid examples of the ar- 
 chitecture of the time of William 
 the Conqueror. 
 
 In all these buildings the cha- 
 racter of simplicity is preserved, 
 
 but some ornament in the details 
 begins to make its appearance be- 
 fore the close of the Conqueror's 
 reign, as, for instance, in the em- 
 battled frette moulding round the 
 arches of the nave of Matilda's 
 church at Caen, in some parts of 
 St. Georges de Boscherville, and 
 other places. 
 
 The florid Norman was already 
 developed in the early part of the 
 twelfth century. Of' this style a 
 rich specimen is afforded in the 
 arcade of the nave at Bayeux. 
 The arches are ornamented with a 
 multiplicity and variety of mould- 
 ings of intricate design and elabo- 
 rate execution. 
 
 Another specimen of the florid 
 Norman exists in the neighbour- 
 hood of Bayeux, in the church of 
 St. Gabriel, built by Robert of 
 Gloucester (1128). 
 
 The abbey church of Monti - 
 villiers (1117), and the church at 
 Graville, are instances of the florid 
 style in all its exuberance. 
 Norman Architecture in England. Of 
 the architecture which existed in 
 this country previous to the intro- 
 duction of the Norman there are 
 no certain vestiges. The most 
 competent authorities have deemed 
 that hardly anything which can 
 be proved to be Saxon remains in 
 existence. Parts of a few churches, 
 which have all the marks of a very 
 remote antiquity, and of which the 
 style differs materially from the 
 Norman, may be suspected to be 
 Saxon. Their distinguishing fea- 
 tures are a ruder imitation of the 
 Roman, projecting instead of re- 
 cessed pillars, and the combination 
 of diagonal with perpendicular 
 forms in the external ornaments of 
 towers. Such is the case at the 
 old church of Barton, in Lincoln- 
 shire, and at Earl's Barton, in 
 Northamptonshire. 
 
 Some persons have imagined 
 that the generality of the Saxon 
 churches were merely timber build- 
 ings, but this appears to be a mis- 
 
NOR 
 
 ANGLO-NORMAN ARCHITECTURE. 
 
 NOR 
 
 take ; for in Domesday Book, which 
 takes note of 1700 churches, one, 
 and only one, is specified as being 
 built of wood ; and Henry of Hunt- 
 ingdon, speaking of a particular 
 church, says, " It was not built of 
 stone, but of wood, and covered 
 with reeds, as is the custom in 
 Scotland;" demonstrating that it 
 was not the custom in England. 
 
 Not only were the Saxon churches 
 not merely timber buildings, but 
 some of them were constructed at 
 a considerable expense, and with 
 much architectural ornament. 
 
 In the seventh century, a church 
 was built at Lincoln, which Bede 
 says was of stone, and of good 
 workmanship. The church of the 
 monastery of Wearmouth was 
 erected in 675, by Abbot Benedict 
 Biscopius, a noble Northumbrian, 
 who, at twenty-five years of age, 
 detached himself from the service 
 of King Oswy, and embraced a re- 
 ligious life. He brought over 
 masons from France to build his 
 church in the Roman manner, and, 
 when the building was nearly 
 finished, he procured artificers from 
 the same country, skilled in the 
 mystery of making glass, to glaze 
 the windows. 
 
 The conventual church of Ripon, 
 and the cathedral church of Hex- 
 ham, were both built by Wilfrid, 
 Bishop of York, in the second half 
 of the seventh century ; and were 
 both constructed of stone, and sup- 
 ported by pillars and arches. Wil- 
 frid also imported builders and 
 artists from abroad from Rome, 
 Italy, France, and other countries. 
 
 In the eighth century, the mo- 
 nastery of Croyland was built by 
 Ethelbald, King of Mercia ; and the 
 church of St. Peter at York was 
 rebuilt by Archbishop Albert, and 
 consecrated just before his death, 
 which took place in 780. Alcuin 
 describes this church as having 
 pillars, arches, and porticoes. 
 
 In the ninth century, the pro- 
 gress of the arts was interrupted 
 
 by the constant incursions of the 
 Danes. All that had been done 
 was destroyed ; and little more 
 than repairs, and military works, 
 could be undertaken till the peace- 
 able reign of Edgar, in whose time 
 the abbey of Ramsey was founded, 
 and the church built by Ailwin, 
 then alderman of all England. This 
 church was built in six years, and 
 finished in 974. It was in the 
 form of a cross, and had pillars, 
 arches, and two towers, one of 
 which was supported by four pil- 
 lars, or piers, in the middle of the 
 building. This appears to have 
 been the first English church that 
 had a tower so situated, or that 
 was built in the form of the cross. 
 
 from these descriptions of the 
 Saxon churches, preserved in the 
 early chronicles, it appears that 
 the Saxon style was, like that of 
 every other country, an imitation 
 of the Roman. The abbey church 
 of Ramsey, which was one of the 
 latest, and one of the most cele- 
 brated of the works of the Saxons, 
 was completed in six years. The 
 last Saxon work of importance was 
 the abbey church of Westminster, 
 built by Edward the Confessor, and 
 finished and consecrated in 1065, 
 one year before the Conquest. This 
 church is represented to have been 
 of a different character from that 
 of any preceding structure in Eng- 
 land, and this difference undoubt- 
 edly consisted in an approximation 
 to the Norman method of building. 
 Edward the Confessor had been 
 brought up in Normandy, and was 
 almost reproached for his incessant 
 endeavours to introduce Norman 
 customs and manners. 
 
 The churches and monasteries 
 which arose after the Conquest were 
 constructed after a new manner of 
 building. From all this it appears 
 that there must have been a marked 
 difference between the Saxon and j 
 the Norman fabrics. But, as both ! 
 were an imitation of the Roman, | 
 the difference must have cons.jted 
 
NOR 
 
 ANGLO-NORMAN ARCHITECTURE. 
 
 in the dimensions and the superior 
 workmanship and magnificence of 
 the new structures. It must have 
 been the same style on a grander 
 scale, and executed in a more sci- 
 entific manner. 
 
 At the time of the Conquest the 
 Anglo-Saxons were in every respect 
 a ruder and less civilized race than 
 the Normans had by that time be- 
 come. 
 
 The earliest work of the Nor- 
 mans which exists in this country 
 was conducted by Gundulph, who, 
 after rebuilding his cathedral at 
 Rochester, was employed by Wil- 
 liam to superintend the construc- 
 tion of the White Tower, in the 
 Tower of London, which contains 
 within its walls perhaps the only 
 ecclesiastical remnant of the Con- 
 queror's time at present in ex- 
 istence. 
 
 In the course of the Conqueror's 
 reign, several cathedrals, abbeys, 
 and castles were built, none of 
 which remain in their original 
 state. A remnant of the Con- 
 queror's time existed at Canter- 
 bury till within these few years, 
 the northern tower, at the west 
 end of the cathedral. This was a 
 part of the work of Lanfranc. The 
 stones of which it was built were 
 irregular, and the joints between 
 the courses were wide. 
 
 Several castles have the reputa- 
 tion of being of the Conqueror's 
 time, but, on a close investigrtion, 
 will be found to have been rebuilt 
 in after-years. Such is the case 
 with the castles of Norwich, Ro- 
 chester, the keep at Conisborough, 
 and many others. 
 
 Within less than a century after 
 the Conquest almost all the ca- 
 thedrals and abbey churches of 
 England, besides innumerable pa- 
 rish churches, were either wholly 
 rebuilt or greatly improved by the 
 Normans, on whom William and 
 his successors conferred all the best 
 ecclesiastical preferments. By the 
 introduction of these Norman pre- 
 307 
 
 lates, the Norman style was rapidly 
 diffused ; at first, however, so much 
 affected by the state of art in this 
 country, as to give to the English 
 building the character of a Norman 
 building of much greater antiquity. 
 
 Rufus was a great builder ; his 
 principal work was the great hall 
 of his palace at Westminster. This 
 hall, as it now exists, was altered 
 by Richard II., but much of the 
 original work was left, and during 
 the late repairs, portions of this 
 were visible. The lower part of 
 the walls was faced with rubble ; 
 the courses were irregular ; the 
 joints wide. Remains of a tri- 
 forium or gallery were discovered, 
 which had been carried along the 
 sides of the hall, half way up. The 
 capitals of the pillars on which the 
 round arches of this gallery rested 
 were plain cubes. The whole of 
 the workmanship was coarse. 
 
 The plan of the churches erected 
 about this time was the same as in 
 Normandy. All were built with 
 the semicircular chancel, which in 
 England afterwards fell into such 
 general disuse that few traces of its 
 existence are to be found in this 
 country. It is, however, to be 
 traced in that of St. Bartholoim \v- 
 le-Grand, in London (begun in 
 1123), in the minster at York, at 
 East Harn,Essex,and in otherplaces. 
 
 The arches of the nave usually 
 rested on those heavy cylindrical 
 piers which in French churches 
 are hardly ever to be found, except 
 in crypts. Their prevalence in 
 England must be ascribed to the 
 inexpertness of the native work- 
 men, and the probability is, that 
 they had previously been adopted 
 by the Saxons from their inability 
 to imitate the Roman style in a 
 more satisfactory manner. Some- 
 times, to adorn the cylindrical piers, 
 the Anglo-Normans introduced the 
 spiral groove winding round them, 
 with the net or lozenge - work 
 spreading over them. 
 
 The windows and the doors 
 
NOR 
 
 ANGLO-NORMAN ARCHITECTURE. 
 
 NOR 
 
 were the same as in Normandy, 
 and the Norman mouldings were 
 gradually introduced with little 
 alteration. 
 
 The walls are remarkably thick, 
 and without prominent buttresses. 
 
 Specimens of the time of Rufus 
 are to be seen in the choir, side 
 aisles, and middle transept at Dur- 
 ham ; in the walls of the lower 
 part of the western facade of Lin- 
 coln ; the towers and transept of 
 St. Alban's; the oldest remaining 
 parts of Winchester ; and the east 
 end and cross aisle of Worcester. 
 
 The walls in this reign were 
 irregularly built, and the joints 
 continued to be wide, as may be 
 seen at Durham, Lincoln, Winches- 
 ter, and other places. 
 
 The style prevailed in the early 
 part of the reign of Henry I., as 
 may be seen by Jhe ruins of St. 
 Botolph's priory, Colchester, which 
 was built by Ernulph, a Norman 
 monk, in the first years of that 
 prince. Here are the same heavy 
 cylindrical piers, the same stumpy 
 proportions, the same poverty of 
 mouldings. But in the course of 
 this reign an impulse was given to 
 architecture by one of those men 
 of genius who affect the character 
 of the age in which they live. 
 Roger Poer, Bishop of Salisbury, a 
 Norman by birth, and combining 
 in himself the offices and the qua- 
 lities which, in those times of 
 constant commotion, were often 
 united, was much distinguished as 
 a prelate, a warrior, a statesman, 
 and an architect. William of 
 Malmesbury relates, that the walls 
 which were built under the super- 
 intendence of Roger of Salisbury 
 were so smooth, and had such fine 
 joints, that they seemed to be made 
 of a single stone. Had fine joints 
 been in use before, their appearance 
 in the works of this prelate would 
 not have been so much extolled. 
 The admiration with which they 
 are mentioned gives us the date of 
 the first introduction of fine joints 
 
 in the walls of English buildings. 
 From this time progressive im- 
 provement took place in other 
 parts of the fabric. Something 
 like decoration was added. The 
 portals began to be enriched. The 
 architecture of England ascended 
 to the level of the architecture of 
 Normandy in the time of William 
 the Conqueror. 
 
 Examples of the style of this 
 reign may be seen in the naves at 
 Gloucester, Norwich, Ely. Durham, 
 and Southwell ; also in the lateral 
 towers of Exeter cathedral, built 
 by BishopWarlewast; in St. James's 
 tower, Bury St. Edmund's ; in the 
 ruins of the chapter-house at Ro- 
 chester, built between 1114 and 
 1125, by the same Ernulph who 
 built St. Botolph's at Colchester, 
 and who, on the death of Gundulph, 
 was promoted to the see of Roches- 
 ter ; in the portal of the round 
 church at Cambridge ; in the 
 nave of the church at Dunstable ; 
 in Saint Bartholomew-le-Grand, 
 London, which was begun in. 11 23 ; 
 in St. Sepulchre's, Northampton, 
 built by Simon de Liz, second earl 
 of Northampton, on his return 
 from the Holy Land, and who died 
 in 1127 ; and in the abbey church 
 of Tewkesbury, begun by Robert 
 Fitz-Hamon (who died in 1107), 
 and consecrated in 1123. 
 
 EXAMPLES. Portal of the chap- 
 ter-house at Durham, built by 
 Bishop Galfrid Rufus, between 1 133 
 and 1143; church of Castle Acre 
 priory, Norfolk, consecrated in 
 1148 ; church of St. Cross, Hamp- 
 shire ; Hipon minster ; St. Frides- 
 wide (now Christchurch), Oxford, 
 begun not later than 1150, and 
 finished in 1180. 
 
 About this time, or a little later, 
 Domestic architecture began to 
 make its appearance in England, 
 though, from the dimensions and 
 arrangement of some of those build- 
 ings which have come down to 
 our time, it is difficult to determine 
 whether all of them were destined 
 
NOR 
 
 ANGLO-NORMAN ARCHITECTURE. 
 
 NOR 
 
 for dwelling-houses, or were only 
 halls for public occasions, or for 
 the courts of the feudal lords. 
 
 Of these buildings the invariable 
 plan is a parallelogram of two 
 stories ; sometimes a double pa- 
 rallelogram. The lower story was 
 vaulted, as we have seen to have 
 been the custom in Normandy, and 
 it had no internal communication 
 with the upper story. The upper 
 story was approached by an exter- 
 nal staircase, which probably was 
 movable. The only fixed Norman 
 staircase now extant is the one at 
 Canterbury. 
 
 The probability is that the lower 
 story was occupied by the servants, 
 and the upper story by the masters ; 
 but in none of the buildings of this 
 time now extant do there exist any 
 traces of subdivisions. 
 
 An example of Norman Domestic 
 architecture existed in Southwark 
 till within these few years. It was 
 the hostelry or town residence of 
 the priors of Lewes. The church of 
 St. Olave, Southwark, was confirm- 
 ed to the prior and convent of 
 Lewes by William, second Earl 
 Warren and Surrey, the son of the 
 founder. Earl William died in 
 1138. It appears, however, that 
 the priors of Lewes rented a build- 
 ing in 11 70 and 1186, for their oc- 
 cupation in London ; from whence 
 it may be concluded, that the hos- 
 telry in question was not built till 
 after that period. The gene-al 
 features of the portion of the hos- 
 telry which remained till lately 
 nearly resembled those of the 
 manor-house of Boothby Pagnel, 
 Moyse's Hall, at BurySt. Edmund's, 
 and the building which is called the 
 Pythagoras School at Cambridge. 
 
 In 1826 was still existing at 
 Barneck, in Northamptonshire, a 
 Norman manor-house, which was 
 not built for defence. In this in- 
 stance the hall, which was the 
 principal feature, was on the ground 
 floor, and had novaults underneath. 
 The hall consisted of a centre and 
 
 309 o 3 
 
 two side aisles. The fine joints of 
 the walls of this building denoted 
 that it could not have been built 
 much before the middle of the 
 twelfth century. 
 
 At Bury St. Edmund's is a Nor- 
 man domestic building, which goes 
 by the name of Moyse's Hall. 
 
 AU Boothby Pagnel, in Lincoln- 
 shire, is a Norman manor-house on 
 nearly the same plan. In this are 
 a fire-place and a chimney, which 
 indicates that the building of which 
 it forms a part cannot be older than 
 the second half of the twelfth cen- 
 tury. This edifice has windows in 
 the ends as well as the sides, a 
 circumstance which makes it evi- 
 dent that to this building no others 
 could have been attached. It is 
 surrounded by a moat. 
 
 At Christchurch, Hants,is a Nor- 
 man remnant which has also a 
 chimney. 
 
 At Lincoln is a Norman domestic 
 building which goes by the name 
 of ' John of Gaunt's Stables,' but 
 which, in fact, was the public meet- 
 ing-house of a guild. It is so much 
 enriched that it must be placed late 
 in the reign of Henry II. 
 
 These examples prove that about 
 the middle of the twelfth century, 
 mansions, distinct from castles for 
 defence, began to be erected in 
 England ; and that, independent of 
 colleges, abbots' lodgings, and the 
 habitable parts of convents, in- 
 stances existed of Domestic archi- 
 tecture. But it was long before 
 dwelling-houses acquired a charac- 
 ter bearing any relation to the qua- 
 lity of the proprietor, or were con- 
 structed with much regard to con- 
 venience. 
 
 Examples of the Norman style 
 of the time of Henry II. are to be 
 seen in the abbey gateway, Bristol ; 
 in the Galilee, or chapel, at the 
 west end of Durham,built byBishop 
 Pudsey (1154 to 1197), together 
 with the lateral portals of the 
 nave ; in the new nave and great 
 west portal of Rochester, etc. 
 
NOR 
 
 ANGLO-NORMAN ARCHITECTURE. 
 
 NOR 
 
 It was in the latter years of "the 
 reign of Henry II. that the struggle 
 between the Round and the Pointed 
 styles, which is called the Transi- 
 tion, hegan to take place in this 
 country. 
 
 Kirkstal abbey, in Yorkshire, was 
 built in the thirty years preceding 
 1183. The nave arches are pointed, 
 but the pillars are massive, and the 
 windows and portals are round. 
 The church at Roche abbey, though 
 equally in the Transition style, and 
 having round - headed windows 
 above pointed arches, Norman 
 mouldings and capitals, yet is of a 
 less heavy character. Both build- 
 ings, however, denote that during 
 those years the new style was only 
 just beginning to be received in 
 England. 
 
 About the same time (1170), 
 Archbishop Roger employed the 
 Pointed style in the new crypt of 
 York minster. 
 
 But the early examples of the 
 Transition, of which the dates are 
 known with the most undoubted 
 certainty, are the round part of 
 the Temple church, London, which 
 was consecrated in 1185, and the 
 choir of Canterbury cathedral, 
 which was rebuilt after the fire in 
 1175, and in which the Pointed 
 style was introduced by John of 
 Sens, a French architect. Other 
 instances are to be found in the 
 great tower at the west end of Ely, 
 built by Bishop Ridel, who died in 
 1189; in the county hall of Oke- 
 ham, Rutlandshire; in the abbey 
 church of Glastonbury, etc. 
 
 But the nave of Rochester and 
 the nave of Peterborough, rebuilt 
 between 11 70 and 1194, are proofs 
 that the old fashion was not at once 
 superseded by the new. 
 
 Simultaneously with the intro- 
 duction of the Transition style, 
 hewn stone vaults appear to have 
 been first thrown over the wider 
 parts of English churches, which 
 till then had been habitually roofed 
 with wood. A stone vault was 
 
 thrown over the new choir of Can- 
 terbury, in 1174. It was customary 
 before that time, to roof narrow 
 spaces with plain cross-vaulting, 
 but not to vault wide spaces with 
 stone. Plain cross-vaulting of rub- 
 ble, with and without ribs, had 
 been adopted before in crypts, side 
 aisles, and chancels. Barrel-vault- 
 ing, we have seen, was introduced 
 in the time of William the Con- 
 queror. From the time that the 
 choir of Canterbury was built, which 
 was not long after, it became com- 
 mon to throw stone vaults over the 
 naves of the larger churches of 
 Normandy, and huge stone vaults, 
 plain at first, and gradually en- 
 riched, became habitual in Eng- 
 land. Prominent buttresses and 
 flying buttresses, as in Normandy, 
 followed in the train of the stone 
 roofs. 
 
 From this time, the Round style 
 fell gradually into disuse; but at 
 Fountains abbey, the foundations 
 of which were laid in 1204, and 
 which was in progress during the 
 forty subsequent years, the win- 
 dows and portals are still round- 
 headed ; and an instance of a round 
 portal is to be found at Ketton, in 
 Rutlandshire, as late as 1252. 
 
 During the reign of Henry III 
 the Early Pointed style attained its 
 most perfect condition. Fine ex. 
 amples of this style are to be seer 
 in the chapter-house, the transepts 
 and part of the choir of Westmin 
 ter abbey ; in the choir of St. Al 
 ban's ; in the nave of Lincoln ; th< 
 east end of Durham ; nave of Wor 
 cester, 1224; nave and spire o 
 Lichfield ; south transept of York 
 and the older part of the choir o 
 Southwell ; and in Salisbury ca 
 thedral, which was begun in 1221 
 and carried forward, without inter 
 ruption, till it was completed. 
 
 The establishment of the Pointe< 
 style was attended with one re 
 markable difference in Englan< 
 and Normandy. In Normandy, tin 
 semicircular chancel became, ge 
 
NOR 
 
 NUNNERY. 
 
 NUN 
 
 nerally speaking, polygonal; in 
 England, generally speaking, it be- 
 came square. Polygonal chancels 
 are as rare in England as square 
 chancels are in the larger churches 
 of Normandy ; and this difference 
 of shape in England afforded the 
 opportunity of those magnificent 
 east windows, which are so princi- 
 pal and so splendid a feature of our 
 cathedrals. Another difference to 
 be remarked, is the battlement, 
 which usually forms the parapet of 
 English churches, and which never 
 occurs in the ecclesiastical build- 
 ings of France. 
 
 It may be said, 1. That the 
 supposed existence of the Pointed 
 style in Normandy, in 1056, is 
 imaginary. 2. That the Normans, 
 adopting the corrupt Roman style, 
 gave it a character of their own. 
 3. That the Normans greatly con- 
 tributed to the advancement of the 
 arts in England. 4. That archi- 
 tecture performed exactly the same 
 revolution in England and France, 
 France having, in all the changes, 
 a certain precedence. 
 
 Norroy, or North roy, in heraldry, 
 one of the two provincial Kings at 
 Arms, whose jurisdiction lies on 
 the north side of the Trent, as 
 does that of Clarencieux to the 
 south. 
 
 Northampton Tables, Tables made at 
 the county town of Northampton, 
 formed from the registers of burials 
 of that locality, from which calcu- 
 lations were made of the value of 
 life, for the purpose of its insurance. 
 (See article Assurance.} 
 
 Nosing, the prominent edge of a 
 moulding or drip; the projecting 
 moulding on the edge of a step. 
 
 Nosing of steps, the projecting parts 
 of the tread-board or cover, which 
 stand before the riser. The nosing 
 of steps is generally rounded, so as 
 to have a semicircular section ; and 
 in good staircases a hollow is placed 
 under them. 
 
 Notch-board, a board notched or 
 grooved out, to receive and sup- 
 
 311 
 
 port the ends of the steps of a stair- 
 case. 
 
 Notching, the cutting of an excava- 
 tion throughout the whole breadth 
 of a substance : by this means tim- 
 bers are fastened together, or their 
 surfaces, when joined at angles, are 
 made to coincide. 
 
 Nozzles, those portions of a steam en- 
 gine in which are placed the valves 
 that open and close the communi- 
 cation between the cylinder and 
 the boiler and condenser, in low- 
 pressure or condensing engines ; 
 and between the cylinder and boiler 
 and atmosphere, in high-pressure 
 or non-condensing engines. 
 
 Nucleus, the internal part of the floor- 
 ing of the ancients, consisting of a 
 strong cement, over which was laid 
 the pavement, which was bound 
 with mortar. 
 
 Nuisance, anything tending to hurt, 
 to annoy, or to endanger health. 
 (See the excellent work by Mr. 
 Gibbons on this subject.) 
 
 Nullah, in India, a natural canal, or 
 small branch of a river. 
 
 Nunnery, a Roman Catholic building 
 for an association of nuns or females 
 devoted to a life of religious seclu- 
 sion. Previous to the Reformation, 
 there existed in England 127 edi- 
 fices for the convenient lodging of 
 such pious women, 2 in Wales, and 
 20 in Scotland; in the whole in 
 Great Britain, 149. But there 
 were many convents and religious 
 houses not specially named nun- 
 neries, but which were receptacles 
 also for such purposes. 
 
 Nunnery, a term sometimes applied 
 to the triforium or gallery between 
 the aisles of a church and the clere- 
 story ; so called from the situation 
 of the nuns' choir in some convents. 
 At the present time, the roomy 
 galleries over the aisles in West- 
 minster abbey are called nunneries, 
 probably from having been used by 
 the nuns of Kilburne, when they 
 visited the abbey, to which they 
 were subordinate. 
 
 Nut, a short internal screw, which 
 
OAK 
 
 OAK. OBL 
 
 acts in the thread of an external 
 screw, and is employed to fasten 
 anything that may come between 
 
 o 
 
 OAK. There are two kinds of this 
 timher common in England, on the 
 Continent, and in America. Oak of 
 good quality is more durahle than 
 any other wood which attains the 
 same size : its colour is a well- 
 known brown. Oak is a most va- 
 luable wood for ship-building, car- 
 pentry, frames, and works requiring 
 great strength or exposed to the 
 weather. It is also much used for 
 carved ornaments, panelling of 
 rooms, pulpits, stalls, and stand- 
 ards for churches. It is likewise 
 used in the construction of all kinds 
 of buildings, for strength and sta- 
 bility. English oak is one of the 
 hardest of the species : it is consi- 
 derably harder than the American, 
 called white and red Canada oak. 
 African oak is well adapted to the 
 construction of merchant vessels. 
 Italian oak is much purchased for 
 our dockyards, to the prejudice of 
 that which is proudly standing in 
 our several forests. 
 
 Obelisk, in architecture, a quadran- 
 gular pyramid : those of Egypt may 
 be described as large stones, qua- 
 drilateral, diminishing from the 
 base upwards, till, within about a 
 tenth of the height, the sides con- 
 verge to a point. The width of 
 the base is usually about a tenth of 
 the height, to that part where the 
 sides begin to converge : they are 
 commonly formed from a single 
 stone, mostly of granite. There 
 are, however, two small obelisks 
 in the British Museum, formed of 
 basalt, and one at Philae, of sand- 
 stone. When obelisks were first 
 made in Egypt, it was customary 
 with the patriarchs of the Jews to 
 set up stones to perpetuate the 
 memory of great events. Strabo 
 calls such stones ' books of history :' 
 an epithet which might be applied 
 with propriety to the inscribed 
 
 it and a flange on the bottom of 
 the external screw or bolt. 
 
 Egyptian obelisks. The date of 
 the Flaminian obelisk, which is 
 covered with hieroglyphics, is by 
 some writers supposed to be be- 
 tween 1580 and 1600 B.C. The first 
 obelisk was raised by Rameses, 
 King of Egypt, in the time of the 
 Trojan war : it was 40 cubits high, 
 and employed 20,000 men in build- 
 ing. Phins, another king of Egypt, 
 raisedone of 45 cubits, and Ptolemy 
 Philadelphus another of 88 cubits, 
 in memory of Arsinoe, etc. The 
 Romans also erected many, which 
 are well described in Roman history. 
 Oblate, flattened or shortened ; in 
 geometry, a term applied to a sphe- 
 roid, produced by the revolution of 
 a semi-ellipsis about its shorter 
 diameter. Of this figure is the 
 earth, and probably all the planets, 
 having the equatorial diameter 
 greater than the polar. 
 Oblique, in geometry, aslant ; not di- 
 rect ; not perpendicular nor parallel. 
 Oblique angle, one that is greater or 
 
 less than a right angle. 
 Oblique-angled triangle, one that has 
 
 no right angle. 
 
 Oblique arches, or Oblique bridges, are 
 those which conduct high-roads or 
 railroads across a river, canal, etc., 
 in an oblique direction : they are 
 also called skew arches. 
 Oblique line. When one straight line 
 stands upon another, and makes 
 unequal angles therewith, the an- 
 gles are said to be oblique, the one 
 being greater than a right angle, 
 and the other less : hence a line is 
 only oblique as it relates to another 
 line ; otherwise the word would be 
 destitute of meaning. 
 Oblique sailing occurs when a ship, 
 being in some intermediate rhomb 
 between the four cardinal points, 
 makes an oblique angle with the 
 meridian, and continually changes 
 both its latitude and longitude. 
 
OBL 
 
 OBSERVATORY. 
 
 OGE 
 
 Oblong, a rectangle of unequal dimen- 
 sions ; in geometry, longer than 
 broad. 
 
 Observatory, a building erected for 
 the purpose of making observations 
 on the motions of the heavenly 
 bodies. More particularly with re- 
 ference to the study of Terrestrial 
 Magnetism, observatories have been 
 erected by the British Government 
 in Canada, St. Helena, the Cape of 
 Good Hope, and Van Diemen's 
 Land ; by the East India Com- 
 pany at Madras, Singapore, Simla, 
 and Trevandrum ; and by the Rus- 
 sian Government at St. Petersburg 
 and other places, in connection with 
 those at Gottingen, etc. The most 
 muni*icent example of private de- 
 votion to the science of Astronomy 
 is the splendid observatory erected 
 by Lord Rosse at Parsonstown, in 
 Ireland. 
 
 Obtunding, the blunting or taking 
 away a sharp corner. 
 
 Obtuse, in geometry, blunt ; in oppo- 
 sition to acute or sharp. 
 
 Obtuse angle. In geometry, if the 
 contained angle be less than a 
 right angle, it is called an acute ; if 
 greater, it is called an obtuse angle. 
 
 Obtuse-angled triangle, a triangle 
 which has an obtuse angle. 
 
 Obtuse section of a cone, the hyper- 
 bola of ancient geometricans, be- 
 cause they considered it only such 
 a cone whose section through the 
 axis was an obtuse-angled triangle. 
 
 Occus, the banqueting-room of a Ro- 
 man house. There were several 
 kinds of occi, viz. Corinthian, tetra- 
 style, Cyzicene, and Egyptian. In 
 the Greek houses the occi were 
 spacious apartments, in which the 
 mistress of the family employed 
 herself and servants at the loom. 
 
 Ochre, brown, a clay coloured brown 
 by the oxide of iron. 
 
 Ochre, red, a clay coloured red by 
 the oxide of iron. 
 
 Ochre, yellow, a clay coloured yellow 
 by the oxide of iron. 
 
 Octagon, a figure of eight sides and 
 as many angles : when all the sides 
 
 313 
 
 and all the angles are equal, the 
 figure is called a regular octagon. 
 
 Octahedron, in geometry, one of the 
 five regular bodies, consisting of 
 eight equal and equilateral triangles. 
 
 Octostylos, a portico which has eight 
 columns in front. 
 
 Odeum, a small theatre for the re- 
 citation of musical compositions, 
 generally in the neighbourhood of 
 the theatre : the odeum at Athens 
 was contiguous to the theatre of 
 Bacchus ; the odeum at Pompeii 
 also joined the theatre. 
 
 Odontograph, a very ingenious instru- 
 ment, invented by Professor ^A r illis, 
 of Cambridge, to enable the mill- 
 wright, workman, and engineer to 
 measure, draw, and design infinitely 
 in extent, the teeth of wheels. 
 
 Odyssey (In the) we have, for ex- 
 ample, the case of Castor and 
 Pollux, who enjoyed a peculiar 
 privilege of life after death, and 
 revisited earth in some mysterious 
 manner on alternate days, and this 
 too although they were buried. 
 (Gladstone.) 
 
 (Ecus, according to Vitruvius, apart- 
 ments near or connected with the 
 dining-room. 
 
 (Eillcts, or Oylets, small openings or 
 loopholes, sometimes circular ; ex- 
 tensively used in the fortifications 
 of the middle ages. 
 
 Offices, as connected with the domes- 
 tic purposes of large mansions, 
 palaces, etc., consist of kitchens, 
 sculleries, pantries, breweries, wash- 
 houses, etc. ; frequently detached 
 or out-houses, and sometimes in 
 cities, underground and vaulted 
 palaces beneath the same roof. 
 
 Offices, as connected with business, 
 are apartments for the accommo- 
 dation of clerks or accountants; 
 merchants' counting-houses, etc. ; 
 for law clerks, law agents, etc. 
 
 Offing, in navigation, that part of the 
 sea distanced from the shore where 
 there is deep water, and no neces- 
 sity for a pilot. 
 
 Offset, or Set-off, the splay or narrow 
 slanting course of stone or brick, 
 
OGI 
 
 OLIVER. 
 
 ORB 
 
 serving to connect two portion* of 
 a wall, the uppermost of which re- 
 cedes from the face of that beneath. 
 
 Ogee, a moulding consisting of two 
 members, the one concave, the 
 other convex ; the same with what 
 is otherwise called cymatium. In 
 Gothic architecture, ogees are very 
 much employed. The term ogee is 
 also applied to a pointed arch, the 
 sides of which are each formed of 
 two contrasted curves. 
 
 Ogives, arches or branches of a Gothic 
 vault, which, instead of being cir- 
 cular, pass diagonally from one 
 angle to another, and form a cross 
 with the other arches which make 
 the sides of the squares, whereof 
 the ogives are diagonals. The 
 middle, when the ogives cut or 
 cross each other, is called the key, 
 sometimes carved in the form of a 
 rose. The members or mouldings 
 of the ogives are called nerves, 
 branches, or veins ; and the arches 
 which separate the ogives, double 
 arches. 
 
 Oliver, a small lift-hammer, worked 
 by the foot. The hammer head is 
 about 2 inches squares and 10 
 inches long, with a swage tool 
 having a conical crease attached to 
 it, and a corresponding swage is 
 fixed in a square cast-iron anvil- 
 block, about 12 inches square and 
 6 deep, with one or two round 
 holes for punching, etc. The ham- 
 mer handle is about 2 to 2\ feet 
 long, and mounted in a cross- 
 spindle nearly as long, supported 
 in a wooden frame between end- 
 screws, to adjust the groove in the 
 hammer face to that in the anvil- 
 block. A short arm, 5 or 6 inches 
 long, is attached to the right end 
 of the hammer axis ; and from this 
 arm proceeds a rod to a spring- 
 pole overhead, and also a chain to 
 a treadle a little above the floor of 
 the smithy. 
 
 Olympiad, a period of four years, by 
 which the Greeks reckoned their 
 time. The first Olympiad corre- 
 sponds with the 775th year before 
 
 314 
 
 the birth of our Saviour, and 22 
 years before the building of Rome. 
 
 Oolite, the Portland stone used in ar- 
 chitecture, called also freestone 
 and roestone. 
 
 Opa, according to Vitruvius, a bed or 
 cavity in which the head of a tie- 
 beam rests. 
 
 Opaque, cloudy, not transparent. 
 
 Ophites, a black marble. 
 
 Opie (John) was born in Cornwall, 
 1761, and died April, 1807. Home 
 Tooke and Sir James Mackintosh 
 speak very highly of his intellectual 
 powers. He sketched out a plan 
 of weekly study, from which plea- 
 sure or persuasion seldom wiled 
 him. 
 
 Opisthodomos, the enclosed space be- 
 hind a temple: the treasury at 
 Athens was so called, because it 
 stood behind the temple of Mi- 
 nerva. 
 
 Oppidum, according to the Romans, 
 a mass of buildings : an entrance 
 to a town ; the facade to a public 
 building, not unlike to the termini 
 on the principal lines of railway. 
 
 Opposite angles, those which are 
 formed by two straight lines cross- 
 ing each other, but not two adja- 
 cent angles. 
 
 Opposite cones are those to which a 
 straight line can be everywhere 
 applied on the surface of both 
 cones. 
 
 Opposite sections, those made by a 
 plane cutting two opposite cones. 
 
 Optics, the science of direct vision, 
 including catoptrics, dioptrics, and 
 perspective. 
 
 Optostrotnm, according to the Greek, 
 a brick-paved flooring. 
 
 Opus, Roman reticulated masonry : a 
 mode of workmanship. 
 
 Or, in heraldry, gold : it is denoted 
 in engraving by small points all 
 over the field or bearing. 
 
 Ora, a Roman hawser. 
 
 Oratory, a small private chapel or 
 closet for devotion. 
 
 Orb, a mediaeval term for a blind 
 window. 
 
 Orbs, in Gothic ornament, bosses and 
 
ORB 
 
 ORDNANCE SURVEY. 
 
 ORD 
 
 knots of foliage, flowers, or other 
 ornament in cornices. 
 
 Orbiculus, according to Vitruvius, a 
 roller or a pulley revolving upon 
 an axis, and having a groove in its 
 circumference for the rope to fit 
 into ; employed as a mechanical 
 power for raising or drawing. 
 
 Orchestra, the area in the Greek 
 theatre comprised between the 
 lower range of seats and the pro- 
 scenium. In the Roman theatre, 
 the orchestra was appropriated to 
 the senators ; but in the theatres 
 of the Greeks it was the scene of 
 action of the dancers. 
 
 Orders qfArchitecture,usu&\\y named 
 the ' ti ve orders,' without reference 
 to other styles of architecture, are 
 thus enumerated by most writers : 
 1. Tuscan. 2. Doric. 3. Ionic. 
 4. Corinthian. 5. Composite. (For 
 their proportions, see Architec- 
 ture.} 
 
 Ordinates, in geometry and conies, 
 lines drawn from any point of the 
 circumference of an ellipse, or 
 other conic section, perpendicularly 
 across the axis, to the other side. 
 
 Ordnance Survey of Great Britain and 
 Ireland : a work of great import- 
 ance in ascertaining the true geo- 
 graphical position of our islands 
 and of their varied superficial fea- 
 tures. This survey originated in 
 the mutual desire on the part of 
 English and French philosophers 
 to determine the precise difference 
 of longitude between the nreridi- 
 ans of the Greenwich and Paris 
 observatories. In the pursuit of 
 this object, a meeting was arranged 
 at Dover between three members 
 of the French Academy, MM. Cas- 
 sini, Mechain, and Legendre, and 
 General Roy and Dr. Blagden, to 
 arrange plans of operation. In the 
 course of the subsequent survey, 
 the officers of the Royal Artillery, 
 to whom the superintendence of 
 the work was entrusted, extended 
 their views and operations, and, 
 under the patronage and at the 
 expense of the Board of Ordnance, 
 
 315 
 
 proceeded to determine the length 
 of as many degrees on the meridian 
 as came within the limits of the 
 survey. The rules by which the 
 main lines for this and all other 
 extended surveys are obtained, 
 are derived from the principles of 
 trigonometry, or the properties of 
 triangles. By these principles we 
 are enabled to compute the exact 
 form and dimensions of any triangle 
 from the actual measurement of 
 one side only, and of the angles 
 formed at its extremities by the 
 other sides. Upon these principles 
 the true figure and size of our 
 globe have been determined upon 
 the relative lengths of degrees of 
 a meridian in different latitudes. 
 
 The exactness of the results of 
 these operations depending upon 
 the correct measurement of the 
 one side, or base-line, and of the 
 angles at its ends, formed by the 
 two imaginary sides which have 
 a common meeting point in some 
 distant and conspicuous object, the 
 apparatus for measuring this side 
 and the angle is required to act 
 with extreme delicacy and exact- 
 ness. For measuring the length, 
 rods of various materials have been 
 used, and endeavours made to 
 obviate the effect of changes of 
 temperature in altering the length 
 of the rods themselves. General 
 Roy commenced the measurement 
 of a base line on Hounslow Heath 
 with rods of deal, each twenty 
 feet long. But these rods, although 
 prepared in the most careful man- 
 ner, of the best seasoned timber, 
 perfectly straight, and effectually 
 secured against bending, were 
 found to suffer such changes of 
 length, from the varying dryness 
 and moisture of the air, as ren- 
 dered them utterly unfit for the 
 purpose, and glass tubes were 
 eventually substituted, each of 
 them twenty feet long, and en- 
 closed in a frame of wood, allow- 
 ing only expansion or contraction 
 in length from heat or cold ac- 
 
ORD 
 
 ORGAN. 
 
 ORG 
 
 cording to a law ascertained by 
 experiments. With these rods a 
 base of about 5 miles in length 
 was measured so exactly, that a 
 remeasurement by Colonel Mudge 
 several years afterwards, made with 
 a steel chain constructed by the 
 celebrated Ramsden, differed only 
 from the original line to the extent 
 of 2f in. Steel chains are jointed 
 similar to a watch-chain, and are 
 always used with uniform tension, 
 the differences in length due to 
 temperature being calculated upon 
 the observed fact, that each degree 
 of heat above 62 Fahr. extends the 
 chain -0076 of an inch. 
 
 For determining the angles, the 
 English officers used an excellent 
 theodolite by Ramsden, having 
 both an altitude and an azimuth 
 circle, and a telescope of great 
 power. This instrument, com- 
 bining the powers of a theodolite, 
 a quadrant, and a transit instru- 
 ment, is capable of measuring hori- 
 zontal angles to fractions of a 
 second. It is recorded among the 
 proofs of the accuracy attained in 
 this triangulation, that a testing 
 line, or base of verification, as 
 termed in geodesic operations, 
 measured on Salisbury Plain, of 
 which the length exceeded seven 
 miles, differed only one inch from 
 the computation carried through 
 the series of triangles from Houns- 
 low Heath to Salisbury Plain. 
 
 When the primary triangulation 
 had been thus carefully completed, 
 a further subdivision of each of 
 these great triangles was perform- 
 ed, and each of these again was 
 subdivided into others, so that the 
 entire plot of the country was re- 
 presented by a complete network 
 of triangles. Each of these divi- 
 sions and subdivisions being form- 
 ed independently of the others, 
 and yet the exact accordance of 
 the whole being insisted on and 
 effected, accuracy is secured in all 
 these principal operations, and the 
 filling in of each of these spaces 
 
 is entrusted to a different class 
 of operators, whose labours in pro- 
 ducing the final plan are so divided 
 and arranged that the work of 
 each is a check upon the exactness 
 of his predecessor. Thus the sur- 
 veyors measure the lines and angles 
 on the ground, but another class 
 of assistants (the plotters) produce 
 the plan from the records of the 
 surveyors, and a third class (ex- 
 aminers) test the plan thus pro- 
 duced by subsequent comparison 
 in the field. One effect of this 
 system, by which the range of ope- 
 rations confided to each operator 
 is thus limited, and the fidelity of 
 these thus severely scrutinized, is, 
 that the bulk of the work after 
 the triangulation may be safely 
 confided to an inferior and cheaply 
 engaged class of assistants, and 
 great comparative economy thus 
 attained. 
 
 The Ordnance Survey of Great 
 Britain and Ireland is plotted to 
 different scales. 
 
 Organ. This word is derived from 
 the Greek organon: organum in 
 Latin, organo in Italian, orgue in 
 French, orgel in German. It signi- 
 fies, generally, an instrument ; but 
 is now used for the name of the 
 grandest and most worthy of mu- 
 sical instruments. 
 
 The tones of an organ are pro- 
 duced from the pipes only ; of 
 these some are of wood, others of 
 various kinds of metal, and even of 
 glass. An organ of full compass 
 may contain all the sounds recog- 
 nized in the science of music, from 
 the lowest appreciable to the very 
 highest. The largest pipes pro- 
 duce the lowest sounds, and some 
 few are made as long as about 32 
 feet, while the smallest are about 
 the size of the pipe of a very small 
 key. Organs are of various kinds, 
 viz. for the church, the concert- 
 room, and for the private drawing- 
 room. The church organ should 
 be of a full, deep, and solemn cha- 
 racter ; while the concert-room 
 
3RG 
 
 ORGAN. 
 
 ORG 
 
 organ should be of a lighter and 
 more brilliant kind, with every va- 
 riety of stop, in order to imitate, 
 not only the full orchestra, but also 
 certain ' solo' instruments. Hence 
 we have the flute-stop ; the, haut- 
 boy, the cremona or krum-horn, 
 the vox-humana, etc. stops; ac- 
 cording to the extent of the instru- 
 ment. These solo, or fancy stops, 
 belong only to the concert-room 
 or drawing-room organ, and are 
 wholly unbecoming in one for the 
 church. 
 
 We have not space to give any- 
 thing like a description of this 
 the noblest of instruments ; and 
 it must suffice to say that it con- 
 sists of bellows which supply the 
 pipes with wind by means of a 
 wind-chest ; the wind being con- 
 veyed therefrom, through channels, 
 under the different ranks, or rows 
 of pipes, and thence into the pipes 
 by means of pallets, or valves, 
 opened at the pleasure of the per- 
 former, by pressing the proper 
 lever or key. 
 
 The organ is a very ancient in- 
 strument of the church, and must 
 have been very unwieldy, since we 
 are told of one in the cathedral 
 church at Halberstadt, which had 
 only a few large pipes, and the 
 keys were more than a hand- 
 breadth in width, and were beaten 
 or pressed down by the fist, or 
 elbow ; the wind being supplied by 
 several small bellows. We are also 
 told of the Winchester organ, which 
 required seventy men to supply it 
 with wind ; its compass was of ten 
 notes only, although it had 400 
 pipes, i. e. forty to each note ; it 
 was so loud that it could be heard 
 all over the city. The organ is 
 usually described as being of three 
 kinds, the great, or full chorus 
 organ, the swell organ, and the 
 choir organ : the latter is used to 
 accompany the softer parts of the 
 music, and is such an instrument 
 as was carried in the ancient pro- 
 cessions, in the rogation days, and 
 
 317 
 
 other seasons, to accompany the 
 priests with while chanting the 
 litanies ; the performer, or, more 
 properly speaking, the minister at 
 the organ, being carried also with 
 the instrument, and seated : hence 
 this organ was called the chair 
 organ, now corrupted into choir 
 organ, from the difference in its 
 employment. The swell organ is 
 used chiefly to accompany solos ; 
 for interludes, and such like fanci- 
 ful music, and takes its name from 
 being able to swell out its sounds 
 by openings made by turning a 
 series of boards on their centres, 
 similar to a Venetian blind, these 
 boards being connected by levers 
 under the control of the per- 
 former's foot. 
 
 The key-board, or row of keys 
 of an organ, are like those of a 
 pianoforte, only they require to be 
 pressed down (not struck like those 
 of the latter instrument), so as to 
 open the pallets before mentioned, 
 and cause the pipes to speak. A 
 complete church organ contains 
 three rows of keys, one for each of 
 the above-mentioned organs ; and 
 most organs have also a row of 
 keys called pedals, to enable the 
 organist to play the bass-notes with 
 his feet. 
 
 In organs that are played by 
 means of a wind, or handle, the 
 part of the organist is performed 
 by a cylinder, on which are placed 
 a number of wires so contrived 
 as to press upon the levers, and 
 open the pallets or valves ; and 
 hence those instruments are called 
 barrel organs. They are of little 
 or no use for the purposes of the 
 church. It has been the fashion, 
 for some time, to make one organ 
 do the work of two, namely, the 
 full organ and the choir organ : 
 but it is at best but a sorry con- 
 trivance ; for in such an organ 
 there can be no good choir organ 
 mixture ; and the full organ is ge- 
 nerally too noisy, the fullness being 
 made up of loud-voiced pipes, in- 
 
ORG 
 
 OSCILLATING ENGINE. 
 
 OXI 
 
 stead of their being round, mellow, 
 and full-toned. These kinds of 
 organs have not the dignified and 
 solemn character necessary for real 
 church music. 
 
 Organ screen, an ornamental stone 
 wall or piece of timber framework, 
 on which a church organ is placed, 
 and which in English cathedrals 
 and churches forms usually the 
 western termination of the choir. 
 
 Organum, a name given to a machine 
 or contrivance in aid of the exercise 
 of human labour in architecture 
 and other arts. 
 
 Oriel window, a projecting angular 
 window, mostly of a triagonal or 
 pentagonal form, and divided by 
 mullions and transoms into differ- 
 ent bays and other proportions. 
 The oriel has been discussed by 
 many writers, but there cannot be 
 conceived an architectural charm 
 more cheerful to the interior, or 
 more decorative to the exterior of 
 a building, than an oriel window. 
 
 Orlop, in shipping, the middle deck. 
 
 Ornithon, an aviary or poultry-house, 
 or the appurtenance to a farm villa. 
 
 Orrery, in mechanics, a machine 
 which by many complicated move- 
 ments represents the revolutions 
 of the heavenly bodies. 
 
 Orthography, in architecture, the ele- 
 vation of a building, showing all 
 the parts thereof in their true pro- 
 portions : the orthography is either 
 external or internal. The external 
 is the delineation of the outer face 
 or front of a building ; the internal 
 is a section of the same. 
 
 Oscillating Engine, a marine engine, 
 with a vibrating cylinder, having 
 the piston rod connected to the 
 crank, and the cylinder supported 
 by the trunnions projecting from 
 the sides at or near the centre, 
 cast hollow, and connected to the 
 steam and eduction pipes. 
 
 Oscillation, or vibration, in mechanics, 
 the act of moving backward and 
 forward like a pendulum. 
 
 Oscillation, the axis of, in mechanics, 
 a right line parallel to the apparent 
 
 318 
 
 horizontal one, and passing through 
 the centre, about which the pen- 
 dulum oscillates. 
 
 Osterly House. " The opulence and 
 gallantry of Sir Thomas Gresham 
 rivalled the wonders of romance. 
 Que*en Elizabeth had visited that 
 superb mansion, and on quitting 
 the window to seek her bed, had 
 remarked aloud, ' How much more 
 gracefully the court-yard would 
 appear if divided in two by a wall.' 
 The words were caught up by Sir 
 Thomas, who instantly, on quitting 
 the royal presence, sent hastily to 
 his masons and bricklayers, assisted 
 them with innumerable labourers, 
 worked all the night, and completed 
 the wall according to the Queen's 
 wishes before she had risen from 
 her bed. The courtiers were cha- 
 grined at the knight's abruptness, 
 and one of them consoled himself 
 with a conceit, ' that it was no way 
 strange that one who could build 
 a 'change could change a build- 
 ing.' " 
 
 Ostium, an inner door, the door of 
 a chamber. 
 
 Outward angle, the same as a salient 
 angle. 
 
 Ova, in architecture, ornaments in 
 the form of eggs, carved on the 
 contour of the ovolo, or quarter- 
 round, and separated from each 
 other by anchors and arrow-heads. 
 
 Oval, a figure in geometry, bounded 
 by a curve-line returning to itself. 
 
 Overshot -wheel, a wheel driven by 
 the weight of water conveyed into 
 buckets, disposed on its circumfer- 
 ence so that one part of the wheel 
 is loaded with water while the 
 other is empty. 
 
 Over story, the clear story or upper 
 story of a building. 
 
 Ovolo, a convex moulding, mostly used 
 in classical architecture ; in the 
 Roman examples it is an exact 
 quarter of a circle ; in Grecian it is 
 more flat and quirked at the top. 
 It is frequently used in the deco- 
 rated Gothic style. 
 
 Oxidation, rusting ; the process o1 
 
OXY 
 
 PAINTING. 
 
 PAI 
 
 converting metals and other sub- 
 stances into oxides, by combining 
 a certain portion of oxygen with 
 them. 
 Oxygen, in chemistry, a gaseous ele- 
 
 ment of great importance in the 
 economy of Nature : it is essen- 
 tial to the maintenance of organic 
 life : hence its original name, ' vital 
 air.' 
 
 P. 
 
 CK, a quantity of material, either 
 wood or coals, placed or piled up 
 to support roofs, or for other pur- 
 poses. 
 
 Paddle-shaft, the shaft upon which 
 the paddle-wheel is fixed, placed 
 centrally with, and connected to, 
 the crank -shaft. 
 
 'addle-wheel, the wheel fixed upon 
 the paddle-shaft, for propelling a 
 vessel through the water by the 
 action of a number of paddle- 
 boards fixed at the circumference. 
 
 Pagoda, in architecture, a name ap- 
 plied by the Europeans to Hindoo 
 temples and places of worship, but 
 not by the Hindoos themselves, 
 who have no such appellation ; they 
 are square stone buildings, not very 
 lofty, crowned with a cupola : the 
 pagodas of China are, however, 
 lofty houses, which sometimes rise 
 to the height of nine stories, of 
 more than twenty feet each. The 
 buildings are depositories of their 
 idols, and used for their worship. 
 
 Painted and Stained Glass, formerly 
 used exclusively for ecclesiastical 
 purposes, displaying devotion 
 and spiritual bearing. Latterly 
 painted and stained glass have 
 been used for domestic purposes. 
 The art of painting on glass was 
 known as early as the sixth century, 
 and was applied to the enrichment 
 of the basilica of St. Sophia, and 
 other churches in Constantinople ; 
 and in the reign of Charlemagne 
 some progress was made in enrich- 
 ing and beautifying glass with 
 colours. In the tenth century it 
 was much admired, and advanced 
 rapidly : Henry II. patronized this 
 art. In France it progressed in all 
 the magnificence of colour and exe- 
 cution, and was extensively diffused 
 
 319 
 
 in England. Tn Canterbury- and 
 York some beautiful examples re- 
 main, for the admiration and ex- 
 ample of modern practice. Of the 
 cinque-cento style, the revival of 
 art under the immortal Albert 
 Diirer, some very fine specimens of 
 the period, picturesquely drawn, are 
 to be found in fine preservation in 
 St. Jacques, at Liege ; and of ra- 
 ther a later time, those of the 
 Crabeths, at Gouda, in Holland, are 
 magnificent executions of this art 
 by these brothers. One of these 
 windows, upwards of 70 feet high, 
 was executed by Theodore Crabeth, 
 by command and at the expense of 
 Queen Mary of England, consort of 
 Philip II. : a portion of the picture 
 is magnificently painted, the sub- 
 ject of which is the Queen, with her 
 husband, kneeling at the Lord's 
 table. The upper part of this win- 
 dow has been destroyed by a storm, 
 but the subject referred to remains 
 perfect, and exhibits correct like- 
 nesses of these sovereigns. 
 Painting. The art of painting gives 
 the most direct and expressive re- 
 presentation of objects ; and it was 
 doubtless for this reason employed 
 by many nations, before the art of 
 writing was invented, to commu- 
 nicate their thoughts, and to con- 
 vey intelligence to distant places. 
 The pencil may be said to write a 
 universal language, for every one can 
 instantly understand the meaning of 
 a painter, provided he be faithful to 
 the rules of his art : his skill enables 
 him to display the various scenes 
 of nature at one view, and by his 
 delineations of the striking effects 
 of passion, he instantaneously af- 
 fects the soul of the spectator. In- 
 vention in painting consists prin- 
 
PAI 
 
 PANEL. 
 
 PAN 
 
 cipally in three things: first, the 
 choice of a subject properly within 
 the scope of the art ; secondly, the 
 seizure of the most striking and 
 energetic moment of time for re- 
 presentation ; and, lastly, the dis- 
 covery and selection of such objects, 
 and such probable incidental cir- 
 cumstances, as, combined together, 
 may best tend to develope the story 
 or augment the interest of the piece. 
 Architects will often find deco- 
 rations of a room and its furniture 
 well worthy of their study. In 
 houses recently built, both in town 
 and country, the taste of the archi- 
 tect has been called in, to give 
 designs for the arrangement of 
 curtains, for grates, pier tables, 
 chairs, and sofas ; and in many in- 
 stances the superior chasteness of 
 the designs, and the harmony of 
 the whole with the architectural 
 style of the rooms, may be seen, 
 conformable with the different uses 
 to which the rooms are appro- 
 priated. 
 
 Painter, in navigation, a sea term for 
 a rope employed to fasten a boat 
 to the ship, wharf, etc. 
 
 Palaestra, a building appropriated to 
 gymnastic sports. 
 
 Palaces of Persia (the royal country) 
 are at this day castellated, and 
 many villages have towers of de- 
 fence. 
 
 Pale, in heraldry, the third and middle 
 part of the escutcheon. 
 
 Palisander, a name used on the con- 
 tinent for rose-wood. 
 
 Pall, in heraldry, denotes a sort of 
 cross> representing the pallium or 
 archiepiscopal ornament sent from 
 Rome to metropolitans. 
 
 Palls, in ship-building, strong short 
 pieces of iron or wood, placed near 
 the capstan or windlass, so as to 
 prevent their recoiling. 
 
 Palladium, a metal found with pla- 
 tina, but in small quantity. 
 
 Palladium, in antiquity, a wooden 
 image of the goddes ; Minerva or 
 Pallas, the possession of which in- 
 volved the fate of Troy. 
 
 320 
 
 Pallium or Pall, in church rituals, a 
 pontifical ornament worn by popes, 
 patriarchs, primates, and metropo- 
 litans of the Roman church, in the 
 form of a fillet of black silk, over 
 the shoulders, with four red crosses. 
 
 Palm-trees, \vood of great variety, 
 imported from the East and West 
 Indies, but sparingly employed in 
 England for cabinet and marquetry 
 work, and sometimes for billiard- 
 cues, etc. 
 
 Palette (French), in painting, a light 
 board on which the colours are 
 held. 
 
 Palsgrave, in heraldry, a count or 
 earl, who has the overseeing of a 
 palace. 
 
 Pandation, in architecture, a yield- 
 ing or bending in the middle. 
 
 Pane, the light of a window ; for- 
 merly applied also to the sides of 
 a tower, turret, spire, etc. 
 
 Panel, in carpentry, etc., a square 
 piece of any matter inserted be- 
 tween other bodies ; sunken com- 
 partments of wainscoting, ceilings, 
 etc., principally employed in Gothic 
 and Domestic architecture for in- 
 terior fittings. 
 
 Panel, a space or compartment in 
 a wall, generally of English or 
 Flemish oak, and on a ceiling, en- 
 closed within a raised margin. 
 
 Panel, in mining, a heap of ore 
 dressed and ready for sale. 
 
 Panemore, in mechanics, a globular 
 windmill, proposed to be erected 
 in the centre of a ship, for turning 
 wheels and paddles. 
 
 Panoply, in heraldry, complete ar- 
 mour. 
 
 Panorama (Full view], in painting, a 
 picture drawn on the interior sur- 
 face of a large cylinder, represent- 
 ing the objects that can be seen 
 from one station when the observer 
 directs his eye successively to every 
 point of the horizon. 
 
 Pantheon, a temple dedicated to all 
 the gods ; one of the most cele- 
 brated edifices of Rome. 
 
 Pantograph, in mechanics, an instru- 
 ment contrived for the purpose of 
 
PAR 
 
 PARABOLA. 
 
 PAR 
 
 copying drawings, so that the copy 
 may be either similar to or larger 
 or smaller than the original. (See 
 Pentagraph.} 
 
 Para, in Cornish mining, a gang or 
 party of men. 
 
 Parabola, one of the conic sections 
 formed by the intersection of a 
 plane and a cone when the plane 
 passes parallel to the side of the 
 cone. 
 
 Parabolic Pyramidoid, a solid gene- 
 rated by supposing all the squares 
 of 'the ordi nates applicable to the 
 parabola so placed that the axis 
 shall pass through all their centres 
 at right angles, in which case the 
 aggregate of the planes will form 
 the solid called the parabolic pyra- 
 midoid, the solidity of which is 
 equal to the product of the bases 
 and half the altitude. 
 
 Paraboloid or Parabolic Conoid, the 
 solid generated by the rotation of 
 parabola about its axis, which re- 
 mains fixed. A frustum of a pa- 
 raboloid is the lower solid formed 
 by a plane passing parallel to the 
 base of a paraboloid. 
 
 Parabolic spindle, the solid gene- 
 rated by the rotation of a parabolse 
 about any double ordinate. 
 
 Paradise, a private apartment, a 
 study, the private appurtenances 
 to a convent. 
 
 Paradromides, hypaethral walks, at- 
 tached to the Greek palestra. The 
 Romans called these walls xysta ; 
 whereas the xysta of the Greeks 
 were covered porticoes, in which 
 the athletae exercised in winter. 
 
 Parallel, in geometry, is applied to 
 lines, figures, and bodies which are 
 everywhere equidistant from each 
 ' other, or which, if ever so far pro- 
 duced, would never meet. 
 
 Parallel bars, the rods parallel to the 
 centre line of a beam, joining the 
 connecting links at the lower ends. 
 
 Parallel motion, the connection be- 
 tween the top of the piston-rod and 
 the beams : a name given to a con- 
 trivance, invented by James Watt, 
 for converting a reciprocating cir- 
 
 321 
 
 cular motion into an alternating 
 rectilinear motion. 
 
 Parallel ruler, an instrument consist- 
 ing of two wooden, brass, or steel, 
 rulers, equally broad throughout, 
 and so joined together by the cross 
 blades as to open to different inter- 
 vals, and accede and recede, yet 
 still retaining their parallelism. 
 
 Parallelogram, in geometry, a qua- 
 drilateral right-lined figure whose 
 opposite sides are parallel. 
 
 Parallelogram of forces is a phrase 
 denoting the composition of forces, 
 or the finding a single force that 
 shall be equivalent to two or more 
 given forces when acting in given 
 directions. 
 
 Parallelopiped, in geometry, a regular 
 solid, contained under six parallelo- 
 grams, the opposite of which are 
 equal and parallel ; or it is a prism 
 whose base is a parallelogram : it is 
 always triple to a pyramid of the 
 same base and height. 
 
 Parament, the furniture, ornaments, 
 and hangings of an apartment for 
 a room of state. 
 
 Parameter, a constant right line in 
 each of the three conic sections, and 
 otherwise called latus rectum, be- 
 cause it measures the conjugate 
 axes by the same ratio which Las 
 taken place between the axes them- 
 selves, being always a third pro- 
 portion of them. 
 
 Parapet, the upper part of a house, 
 which is above the springing of a 
 roof, arid guards the gutter ; the 
 upper part of a wall, a bridge, a 
 terrace, or balcony, etc. Parapets 
 around the flat roofs of houses in 
 the East are of most ancient date. 
 " When thou buildest a new house, 
 thou shalt make a battlement for 
 thy roof, that thou bring not blood 
 upon thine house, if any man fall 
 from thence." Deut. xxii. 8. 
 
 Parascenium, in ancient theatres, a 
 place behind the scenes to which 
 the actors withdrew to dress and 
 undress themselves. 
 
 ParastalcK, square columns, or antae ; 
 called also parastacles and parasta- 
 
PAR 
 
 PASTICI. 
 
 PA1 
 
 licae. Vitruvius uses the term to 
 signify the square posts placed be- 
 hind the columns of the basilica, 
 for the support of the floors of the 
 upper porticoes. 
 
 Pargeting, parge-work, plaster- work, 
 employed exteriorly for timber 
 houses, as an ornament ; used also 
 in plain jand ornamental work, for 
 both the exterior and interior. 
 
 Paries, the walls of a Grecian house, 
 in contradistinction to the wall of a 
 city ; a small enclosure, such as a 
 court-yard. 
 
 Parlour, a private apartment in a 
 dwelling, usually on the ground 
 floor ; a speaking-room in a con- 
 vent. In the time of Henry VIII. 
 parlours and privy rooms summer 
 parlours, winter parlours were 
 well, comfortably, and conveniently 
 furnished ; a proof that the gentry 
 of that period were not quite so far 
 behind the present race as might 
 be supposed. 
 
 Parsonage-house, a residence of the 
 incumbent of a parish, a building 
 in the vicinity of a church. 
 
 Patera, a round dish, plate, saucer, 
 or goblet. 
 
 Patina, a basin or bowl of earthen- 
 ware, rarely of bronze. 
 
 Parthenon, in architecture, the tem- 
 ple of Minerva at Athens. 
 
 Particle, the minute part of a body, 
 or an assemblage of several atoms 
 of which natural bodies are com- 
 posed. 
 
 Partners, in naval architecture, are 
 thick pieces fitted into a rabbet in 
 the mast carlings, to receive the 
 wedges of the mast ; likewise tem- 
 porary pieces nailed on the deck 
 round the pumps. 
 
 Partridge wood is the produce of the 
 Brazils and the West India Islands : 
 it is sent in large planks, or in 
 round and square logs. It was 
 formerly employed in the Brazils 
 for ship -building, and is known in 
 dockyards as cabbage- wood. 
 
 Party walls are partitions of brick 
 made between buildings in sepa- 
 rate occupations, for preventing the 
 
 322 
 
 spread of fire. These are mad< 
 thicker than the external walls 
 and their thickness, and the neces 
 sity of their use, are regulated hi 
 Act of Parliament, and specified ii 
 some of the clauses of the Building! 
 Act passed in the reign of th< 
 present Queen. 
 
 Parvise, a porch : an open area be 
 fore the entrance of a church. 
 
 Paschal, a stand or candlestick, of j 
 large size, used in Roman Catholi< 
 worship. 
 
 Pasigraphy, the art of universal writ- 
 ing. 
 
 Passant, in heraldry, a term appliec 
 to an animal in a shield appearing 
 to walk leisurely : for most beasts 
 except lions, the word tripping is 
 frequently used instead of passant 
 
 Passion, in painting, implies an emo- 
 tion of the body, attended with 
 certain expressive lines in the face 
 denoting an agitation of soul. 
 
 Pastici, or Imitations in Paintings 
 Teniers understood the union ol 
 colours extremely well, yet Bassan 
 was superior to him in the sweet- 
 ness and vigour of his tints. De 
 Pile recommends it to all persons 
 who would not wish to be deceived 
 by pastici, to compare the taste of 
 design, the colouring and the cha- 
 racter of the pencil, with the ori- 
 ginals. Teniers, Giordano, and 
 Bon Boulloque are those who have 
 appeared with the greatest repu- 
 tation for imitating other great 
 masters ; and, beside these, many 
 other artists have employed them- 
 selves in painting pastici. 
 
 Pastoral staff, the official staff of an 
 archbishop, a bishop, or mitred 
 abbot. 
 
 Patand, the bottom plate or sill of a 
 partition of a screen. 
 
 Paten, a small plate or salver used in 
 the celebration of the eucharist. 
 
 Patents for Inventions are public 
 grants to the inventors of new 
 and useful machinery and processes 
 in the arts, and by which cer- 
 tain privileges are secured to the 
 inventors, for the exclusive use 
 
'AT 
 
 PATENTS FOR INVENTIONS. 
 
 PAT 
 
 and exercise of their inventions 
 during a limited period. Patents 
 are therefore monopolies of a de- 
 finite character ; but being de- 
 signed as a security for the reward 
 of those whose ingenious faculties 
 and practical skill have produced 
 improvements of general utility and 
 value, these monopolies, if justly 
 granted and honestly exercised, are 
 not to be decried as injurious to 
 the public interests, but should be 
 conceded with willingness, and 
 command the liberal protection of 
 the community, which is destined 
 to reap a continual and permanent 
 advantage from the improvements 
 thus fostered in their infant de- 
 velopment. Patents for inventions 
 should therefore be admitted as bar- 
 gains between the inventor on the 
 one hand, and the public on the 
 other; and the abuses to which these 
 bargains are liable arise from the 
 common causes of official corruption 
 and individual cupidity and jealousy. 
 
 The laws under which patents 
 are granted vary in their form in 
 the several European and American 
 States, and are all, in some degree, 
 imperfect, and ineffective of their 
 proper object. 
 
 In the United Kingdom of Great 
 Britain and Ireland patents are 
 granted to the inventor or im- 
 porter from abroad of " any man- 
 ner of new manufacture," one 
 grant covering the whole realm 
 with the Channel Islands and the 
 Isle of Man. The colonies were 
 formerly included in the grant for 
 England when applied for, on pay- 
 ment of extra fees ; but this prac- 
 tice has been discontinued. Pa- 
 tents are granted in the colony of 
 Victoria, and a law has recently 
 been enacted in India for the same 
 purpose. It is also probable that 
 the patent system will become 
 gradually extended to the colonies 
 generally, in a more definite and 
 practical form than it could be 
 when the grant was merely tacked 
 on to the English patent. 
 
 323 
 
 British patents are granted as 
 matters of course, provided certain 
 legal forms are duly complied with, 
 certain stamp duties paid, and the 
 legal advisers of the Crown (the 
 attorney or solicitor-general) are 
 not required by opposing parties 
 to ascertain whether the privilege 
 sought will interfere with any con- 
 temporaneous application, or with 
 any existing patent. But the va- 
 lidity of the patent is entirely at 
 the patentee's own risk. 
 
 The process of soliciting a patent 
 is as follows : The applicant has to 
 petition the Crown to grant Letters 
 Patent for the invention, and he 
 accompanies his petition with a 
 declaration of the grounds of his 
 request, and a specification either 
 provisional or final, by which the 
 invention sought to be protected 
 may be identified. The difference 
 between a provisional and a final 
 specification is, that in the former 
 kind of document the details are 
 reserved : while in the latter they 
 are expressed. Every provisional 
 specification is submitted to the 
 law officer, who on being satisfied 
 of its sufficiency, allows a certifi- 
 cate of provisional protection to be 
 issued. The provisional protection 
 lasts nominally six months, but 
 really only four months ; because 
 the patent will not be granted un- 
 less notice to proceed be given 
 within four months from the date 
 of the original record of the appli- 
 cation. The notice to proceed is 
 inserted in the ' London Gazette,' 
 and the public are at liberty, with- 
 in a period of twenty-one days from 
 the date of the insertion, to enter 
 notice of objections to the granting 
 of the patent. The case is then 
 referred to the law officer, with 
 whom rests the decision between 
 the parties. Should there be no 
 opposition, the patent is granted. 
 Having obtained the Great Seal, 
 the patentee is allowed a period of 
 six months from the original de- 
 posit of his papers, to prepare and 
 
PAT 
 
 PATENTS FOR INVENTIONS. 
 
 file his complete or final specifica- 
 tion (unless he deposited it at first, 
 which is rarely advisable), with the 
 drawings required to illustrate the 
 invention and to give an accurate 
 idea of the mechanism employed. 
 For this purpose great care and 
 judgment are needed, based on a 
 knowledge of former patents, to 
 frame the specification so that it 
 shall explain with sufficient clear- 
 ness the precise nature of the im- 
 provements, and have that value 
 as property which a good specifica- 
 tion of a patent always has. The 
 patent is now complete, and the 
 patentee can safely proceed to 
 practise under it. 
 
 The patentee is enabled, under 
 the authority of the attorney or 
 solicitor-general, to amend his title 
 and specification in case of need, 
 and to disclaim part or parts of his 
 claims, which he may have since 
 found to be untenable. He may 
 also petition for a prolongation of 
 his term, of fourteen years, which 
 petition is referred to the Judicial 
 Committee of the Privy Council, 
 who grant the same if the petitioner 
 make out a case, satisfactory to 
 them, of extraordinary losses, de- 
 lays, or other special reasons for 
 the prolongation. 
 
 The property in a patent can be 
 defended, from infringement by a 
 bill in equity, or by an action at 
 law. It has been recently found, 
 however, that the ordinary courts 
 of law and equity are incapable of 
 dealing satisfactorily with the sci- 
 ence which forms the chief part of 
 the inquiry in a patent case. A 
 special tribunal, to interpret the 
 specification with authority in the 
 first instance, has therefore become 
 a necessity. 
 
 The patent may be assigned in 
 whole or part by the patentee to 
 any number of persons : it may 
 also be mortgaged, and licenses 
 may be granted for the use of the 
 patent in a variety of modes. But 
 all assignments and licenses must 
 
 be registered at the Great Seal 
 Patent Office, in order to give a 
 title to the parties interested. 
 
 The cost of obtaining a patent, 
 including fees for agency, if unop- 
 posed, is 30. But the patent 
 expires at the end of three years, 
 unless a further stamp-duty of 50 
 be paid ; and at the end of seven 
 years, unless a still further stamp 
 duty of 100 be paid. To these 1 
 items should be also added the 
 cost of preparing and copying spe- 
 cification and drawings, the charges 
 for which are, of course, very vari- 
 able, according to length, intri- 
 cacy, etc. 
 
 The expenses and regulations 
 under which the foreign patents 
 are granted vary considerably. The 
 following brief epitome must suffice 
 in this place. 
 
 In the United States of America, 
 patents are granted only to the) 
 absolute inventor, always for four- 
 teen years, and are granted or 
 withheld at the option of the Go- 
 vernment Commissioners of Pa-' 
 tents. The amount of official fees 
 payable depends upon the country 
 of which the applicant is a native. 
 Thus, a citizen of the United 
 States, or a foreigner who has re- 
 sided in the States one year next 
 preceding the application, and has 
 made oath of his intention to be- 
 come a citizen, pays a fee of ^30 ; 
 a subject of the Sovereign of Great 
 Britain, 4^500 ; and any other 
 foreigner, =8*300. If the applica- 
 tion for a patent be rejected by 
 the Commissioner, two-thirds of 
 the fees paid are returnable. 
 
 In France, patents for inventions 
 are granted alike t<5 natives and 
 foreigners, and the duration of the 
 privilege may be fixed by the pa- 
 tentee at five, ten, or fifteen years, 
 the amount of tax being propor- 
 tional to the term, namely, 500 
 francs for five years ; 1000 francs 
 for ten years; and 1500 francs for 
 fifteen years ; payable by annual 
 instalments of 100 francs. The 
 
 324 
 
PAT 
 
 PATENT YELLOW. 
 
 PEA 
 
 patentee thus enjoys the power of 
 relinquishing his invention, if found 
 unprofitable, at any time during 
 the intended terra, by ceasing to 
 pay the annual instalment of fees. 
 In Belgium, patents are granted 
 for five or ten years : imported in- 
 ventions are patentable, and the 
 Government tax, which is not 
 heavy, is paid annually in small 
 instalments, increasing by 10 francs 
 each year. 
 
 In Holland, patents are granted 
 for five, ten, or fifteen years, and 
 may be had for foreign as well as 
 native inventions. The fees for a 
 patent for five years are 150 
 guilders, or 12. 10s. ; and for 
 terms of ten or fifteen years they 
 vary from 300 to 750 guilders, or 
 from 25 to 62. 10s. 
 
 In Prussia, Russia, etc., the Go- 
 vernments exercise a discretionary 
 power in granting or refusing pa- 
 tents, and the laws are of a strin- 
 gent and arbitrary character. 
 
 In Austria, patents are granted 
 for terms from five to fifteen years ; 
 the taxes must be paid when the 
 application is made, and the in- 
 vention put in practice within one 
 year from the date of the grant. 
 
 The German and Italian States 
 have patent laws peculiar to them- 
 selves, but generally similar to 
 those already described. 
 Patent yellow, Turner's yellow, or 
 Montpellier yellow, is a submoriate 
 or chloride of lead, which metal 
 is the basis of the most opaque 
 yellow pigment : it is a hard, pon- 
 derous, sparkling substance of a 
 crystalline texture and bright yel- 
 low colour, hardly inferior, when 
 ground, to chromic yellow. It has 
 an excellent body, and works well 
 in oil or water, but is soon injured, 
 both by the sun's light and impure 
 air ; it is therefore little used, ex- 
 cept for the common purposes of 
 house-painting, etc. 
 Patera, a circular flat ornament, used 
 in Classical architecture ; used also 
 in Gothic and Italian architecture. 
 
 Patriarchs, the. The chief employ- 
 ment of the patriarchs was the 
 care of their cattle, viz. goats, 
 sheep, camels, horned cattle, and 
 asses. There were no horses nor 
 swine among them. Theirs was a 
 pastoral life, and not a life of tillage. 
 They were always in the field, lying 
 under tents, shifting their abode 
 according to the convenience of 
 pasture. 
 
 Paul, the catch which holds a ratchet- 
 wheel, allowing it to turn in one 
 direction only. 
 
 Pavilion, in architecture, a detached 
 building ; an insulated turret, con- 
 tained under a single roof, some- 
 times square and sometimes dome- 
 formed ; named from its resem- 
 blance to the roof of a tent. The late 
 palatial monstrosity at Brighton 
 was called a pavilion. 
 
 Pax, a small tablet, having on it a 
 representation of the crucifixion, or 
 some other Christian symbol, of- 
 fered to the congregation in the 
 Romish church, to be kissed in the 
 celebration of the mass : it was 
 usually of silver, or other metal, 
 with a handle at the back, but was 
 occasionally of other materials ; 
 sometimes it was enamelled, aad 
 set with precious stones. 
 
 Peach-stone, a bluish-green soft stone. 
 
 Pearl-white. There are two pigments 
 of this denomination : one, falsely 
 so called, prepared from bismuth, 
 which turns black in sulphuretted 
 hydrogen gas or any impure air, 
 is employed as a cosmetic : the 
 other is prepared from the waste 
 of pearls and mother-of-pearl, is 
 exquisitely white and of good body 
 in water, but of little force in oil 
 or varnish ; it combines, however, 
 with all other colours, without in- 
 juring the most delicate, and is it- 
 self perfectly permanent and in- 
 noxious. 
 
 Pear-tree, a native European wood ; 
 its colour is a light brown, some- 
 thing of a pale-mahogany or cedar : 
 it is employed by the Tunbridge 
 turners. 
 
PEA 
 
 PEDIMENT. 
 
 PED 
 
 Pea-stone, or pisolite, in mineralogy, 
 pisiform limestone. 
 
 Peat, in mineralogy, a substance con- 
 sisting of the twigs, leaves, and 
 roots of trees, mixed with grass, 
 straw, plants, and weeds, that have 
 lain long in water, and become con- 
 verted into a blackish-brown mass 
 that may be cut with a spade, and 
 dried for fuel. 
 
 Pedestal, in architecture, the lower 
 member of a pillar, named by the 
 Greeks stylobates and stereobates ; 
 also the basis of a statue. In 
 Classical architecture it consists of 
 three divisions : the base, or foot, 
 next the ground, the dado, form- 
 ing the main body, and the cor- 
 nice, or sur-base moulding, at the 
 top. 
 
 Pediment, the triangular plane or sur- 
 face formed by the vertical ter- 
 mination of a roof consisting of 
 two sloping sides ; consequently it 
 so far corresponds with the gable, 
 % but in other respects differs widely 
 "from it. One material difference be- 
 tween them is, that whereas the 
 gable has no cornices, the pediment 
 is bounded by three, viz. a horizon- 
 tal one, beneath it, forming its base, 
 and two sloping or raking ones, as 
 they are technically termed; and 
 the triangular space or surface in- 
 cluded within them is distinguished 
 by the name of the tympanum of the 
 pediment. Another marked differ- 
 ence between them is, that the 
 gable may be of any pitch ; and 
 being merely a continuation of the 
 wall below, instead of being, like 
 the pediment, separated from it by 
 any horizontal mouldings, its pro- 
 portions do not at all depend upon 
 the height or width of the front or 
 compartment of the front which it 
 terminates, but may be an equila- 
 teral triangle, or even considerably 
 more, as to height, and, besides, is 
 in nowise governed by the height 
 of what is beneath it. The pedi- 
 ment, on the contrary, must be pro- 
 portioned to the height of the order 
 which it crowns ; consequently its 
 
 32G 
 
 pitch must be decreased in some- 
 what the same ratio as its length 
 or base is increased, or, in other 
 words, the greater the number of 
 columns beneath a pediment, the 
 lower must the pitch of the latter 
 be. Hence it is hardly possible to 
 place more than eight, or, at the 
 utmost, ten columns beneath a pe- 
 diment, without making the pedi- 
 ment either too low in itself, or else 
 too lofty and heavy a mass in com- 
 parison with the columns beneath 
 it ; thereby not only overloading 
 them the columns being propor- 
 tioned to their entablature alone 
 but also diminishing their impor- 
 tance, and causing the order itself 
 to look almost puny and meagre, 
 while the pediment looks heavy 
 and clumsy. There has been a 
 good deal of mystification about 
 determining the proportion of pe- 
 diments, and special methods have 
 been devised for that purpose, 
 which, however ingenious in them- 
 selves, as such, are anything but ar- 
 tistic, or calculated to secure pleas- 
 ing proportions. Discarding all 
 such methods, it may be laid down 
 as a safe general rule, that the 
 height of the tympanum should 
 accord pretty nearly with that of 
 the entablature beneath the pedi- 
 ment, and not greatly exceed it, 
 under any circumstances. Such is 
 the proportion which Wilkins ap- 
 pears to have observed for the pe- 
 diment of the London University 
 College ; and although that build- 
 ing has a decastyle portico, the pe- 
 diment does not appear too low, 
 whereas that of the National Gal- 
 lery is so, the height of the tym- 
 panum being there less than that 
 of the entablature, notwithstanding 
 that the portico is octastyle. 
 
 The ancients generally made the 
 pediment contribute largely to the 
 embellishment of the structure, by 
 sculpturing its tympanum with 
 figures in high relief, and in some 
 instances by setting it back, and 
 placing entire statues against it ; 
 
FED 
 
 PEDIMENT. 
 
 FED 
 
 and for such display of sculpture 
 the pediment eminently recom- 
 mends itself, both by its conspicu- 
 ous situation, and by offering a far 
 ampler surface for such purpose 
 than any other part of the edifice ; 
 one, moreover, which not only re- 
 quired a higher decoration, for the 
 sake of consistency, but an in- 
 creased degree of it, in order to 
 produce artistic climax and com- 
 pletion. Yet it must be confessed 
 that if its situation marks out the 
 pediment as a very proper place for 
 making a display of decoration, its 
 shape is by no means well adapted 
 for a composition of figures, ex- 
 cept it be that it compels them to 
 be arranged symmetrically, and the 
 principal one to be directly in the 
 centre. Be the subject what it 
 may, the figures must always be 
 disposed in nearly the same man- 
 ner, and not only very convention- 
 ally but very forcedly, particularly 
 towards the extremities, an incon- 
 venience that might be easily over- 
 come by confining the figures to the 
 centre of the tympanum, putting 
 there a group of three or five, and 
 either leaving the rest of the tri- 
 angular space to be quite plain, or 
 else filling it up with mere orna- 
 ment. While this would certainlyjbe 
 a rather less expensive mode than 
 that now practised, and an equally 
 rational one, its not having been 
 adopted before ought to be itself 
 some recommendation of it, as being 
 a laudable infringement of copyLm. 
 conventionalism, and routine. 
 
 Besides sculpture within them, 
 pediments are frequently surmount- 
 ed at their angles and apex with 
 acroteria, namely, low pedestals, 
 upon which are placed either single 
 figures or groups, or else vases, 
 trophies, or other ornaments ; an 
 example of which is furnished by 
 Spencer House, in the Green Park, 
 and still more strikingly by the 
 portico of the East India House. 
 The practice of placing statues 
 upon pediments appears to have 
 
 originated with the Romans, and 
 is somewhat analogous in taste to 
 that of putting them on the summit 
 of monumental columns; for in such 
 situations human figures show only 
 in their general mass as sculptural 
 accessories to the structure, and at 
 a little distance, or seen in a ge- 
 neral view of the building, produce 
 scarcely more effect than so many 
 pinnacles, which last are infinitely 
 more characteristic of Gothic ar- 
 chitecture than in accordance with 
 the character of a classical portico. 
 In Italian and modern architec- 
 ture generally, the pediment is em- 
 ployed as mere decoration in com- 
 positions for the dressings of both 
 doors and windows, which prac- 
 tice, like that of applying columns 
 for the same purpose, has been 
 condemned by some in the most 
 unqualified manner ; and one writer 
 has vituperated, and endeavoured 
 to bring it into disgrace, by com- 
 paring pediments over doors and 
 windows to cocked hats ! The 
 resemblance which he perceives, 
 or faiicies, between a cocked hat 
 and a pediment is not a particu- 
 larly flattering one ; but if it exists 
 at all, the injurious comparison 
 holds equally good with regard to 
 a large pediment as a small one ; 
 therefore, whether it be that over a 
 portico or over a window, the shape 
 itself is, in either case, the most 
 unfortunate one of a cocked hat ; 
 yet, as cocked hats are now gone 
 quite out of fashion, the unlucky 
 resemblance to them is not at all 
 likely to be detected. In matters 
 of decoration, some latitude some 
 little departure from strict archi- 
 tectural logic is allowable ; other- 
 wise a very great deal in Italian or 
 modern architecture must be pro- 
 nounced decidedly faulty. If it 
 be a solecism to place pediments 
 whose form is derived from that of 
 a roof, over windows, or where no 
 roof exists, the same objection lies 
 against applying entablature whose 
 cornices, resemble the horizontal 
 
 327 
 
 p 2 
 
PED 
 
 PEDOMETER. 
 
 PEL 
 
 ones of a roof, to mere opening* in 
 the wall ; and in like manner, if it 
 be a gross impropriety to flank 
 windows with small columns, it 
 must be as great, if not a greater 
 one, to introduce, merely for the 
 sake of decoration, a large order 
 whose columns are partly buried 
 in the wall, and support nothing 
 but an entablature, or pieces of it, 
 wholly unnecessary in themselves, 
 and put there only that the columns 
 may appear to support something. 
 Again, as to the objection which 
 has sometimes been urged against 
 pediments over doors within a 
 building, namely, those intended 
 to throw off rain, they should be 
 introduced only in external situa- 
 tions, it partakes of the same kind 
 of hypercriticism as the other ; or, 
 if strict rationality is to be uni- 
 formly enforced in architectural 
 design, we must condemn a great 
 deal in the Gothic style as being 
 exceedingly licentious and irra- 
 tional ; for in that we find a great 
 many members and features origi- 
 nating in forms intended for pur- 
 poses of actual service externally, 
 converted into mere interior de- 
 coration ; for instance, embattle- 
 ments on the tops of screens, minia- 
 ture buttresses for ornament instead 
 of strength, miniature spires, and 
 miniature blank windows in orna- 
 mental panelling. 
 
 Pediments are generally placed 
 only over the windows of the 
 principal floor of a building, to 
 which they serve to give distinc- 
 tion and importance. Window 
 pediments are either angular or 
 curved (i. e. segmental), and both 
 forms are frequently introduced 
 together, and placed alternately, 
 in which case it is usual to place 
 an angular pediment over the cen- 
 tre window. Sometimes the centre 
 window alone is crowned with a 
 pediment. When all the pedi- 
 ments are alike, they are almost 
 invariably angular, although there 
 are instances of the contrary, as 
 
 in Bridgewater House, where Mr. 
 Barry has given segmental pedi- 
 ments to all the windows of the 
 principal floor, and has even put 
 them over the centre openings of 
 the triple windows ; and it de- 
 serves to be further remarked, that 
 he has enriched their tympanums 
 with sculptured ornament a de- 
 gree of decoration very rarely in- 
 dulged in. A far more remarkable 
 instance perhaps a unique one 
 may be seen in the house lately 
 erected for Mr. Hope in Piccadilly, 
 large segmental pediments being 
 there placed over windows consist- 
 ing of two openings, consequently 
 forming square, or nearly square, 
 instead of upright compositions. 
 In that instance, too, the pedi- 
 ments are filled in with sculpture ; 
 the figures, however, are not ex- 
 actly confined to the pediments, 
 but come somewhat lower down, 
 the horizontal cornice being partly 
 suppressed for that purpose. 
 
 Pedometer, in mechanics, an instru- 
 ment in the form of a watch, con- 
 sisting of various wheels, with the 
 teeth catching in each other, and 
 which, by means of a string fastened 
 to anything in motion, numbers 
 the paces gone over from one place 
 to another. 
 
 Peek, in navigation, a name given to 
 the upper corners of sails extended 
 by a gaff, or by a yard crossing the 
 mast obliquely, as the mizen-yard 
 of a ship. The upper extremity of 
 those gaffs and yards is also called 
 the peek. To ' peek the mizen' is 
 to put the mizen-yard perpendicu- 
 lar to the mast. 
 
 Peek-halyards, the ropes or tackles 
 by which the outer end of the gaff 
 is hoisted. 
 
 Peg-tankard, an ancient species of 
 wassail-bowl, used in the time of 
 Queen Elizabeth. It held two 
 quarts, and had generally a row of 
 seven pegs, dividing the height into 
 eight equal parts, each containing 
 half a pint. 
 
 Pelasgic Life. In reference to the 
 
 398 
 
PEL 
 
 PENTELIC. 
 
 PER 
 
 Pelasgian people as early settlers 
 in Greece, the Right Honourable 
 W. E. Gladstone, in his recent 
 admirable work, ' Studies on Ho- 
 mer,' says, " For the first agricul- 
 tural settlers must often be dwellers 
 in woods. It may be said that in 
 the United States, at the present 
 day, the proper name for an agri- 
 cultural settler is ' backwoodsman/ 
 In British Australia, they who 
 pass beyond the limits of existing 
 settlement, in order to extend it, 
 are said to go into the bush. Thus 
 the idea at the root of the Lycian 
 name is in all probability twin, or 
 rather elder brother to that which 
 properly would indicate the agri- 
 cultural settler." 
 
 Pelasgm. Taken literally, Pelasgus 
 is the son of the Earthborn, and 
 the name given to the Pelasgian 
 race. What the passage signifies 
 evidently is, that by ancient tradi- 
 
 . tion the Pelasgians were the first 
 occupants of the country. Thucy- 
 dides describes the spot or building 
 called He\a(ryiK6v, under the Acro- 
 polis at Athens, the very situation 
 in which the original town would, 
 in all likelihood, be placed for 
 safety. This historian also sustains, 
 with the weight of his judgment, 
 the opinion that in pre- Hellenic 
 times the prevailing race and name 
 in Greece were Pelasgic (pp. 186- 
 197). 
 
 Pendant, SM ornament suspended from 
 the roof of a Gothic or Tudor build- 
 ing ; the hanging pendants of a 
 vaulted ceiling, uniting solidity with 
 ornament. The most remarkable 
 are those in King Henry VII. 's 
 chapel at Westminster abbey. 
 
 Pendentive, the portion of a groined 
 ceiling supported and bounded by 
 the apex of the longitudinal and 
 transverse vaults. In Gothic ceil- 
 ings of this kind the ribs of the 
 vaults descend from the apex to 
 the impost of each pendentive, 
 where they become united. 
 
 Pennyweight, the twentieth part of 
 an ounce. 
 
 329 
 
 Pentagon, a figure of five angles and 
 five sides : when these are equal it ! 
 is called a regular pentagon, but ! 
 otherwise it is irregular. 
 
 Pentagraph, an instrument whereby 
 designs, prints, etc., may be copied, 
 in any proportion, without a person 
 being skilled in drawing. (See 
 Pantograph.) 
 
 Pentangular, in geometry, five-cor- 
 nered or angled. 
 
 Pentastyle, in architecture, a work in 
 which there are five rows of co- 
 lumns. 
 
 Pentelie marble, in statuary, a beau- 
 tiful and glossy variety of Parian 
 and Carrara marble, named from 
 Mount Pentelicus, near Athens, 
 where it was quarried. Pentelie 
 marble, from the smallness of the 
 grain, is mistaken for the Parian ; 
 but, of the two, the former is of a 
 finer quality. The Pentelie quar- 
 ries display in a remarkable man- 
 ner the energies of the ancient 
 Athenians ; whole sides of the 
 mountains have disappeared, and 
 present uniformly cut perpendicular 
 cliffs : and holes, still to be traced 
 on the slope of the quarries, made 
 for the insertion of capstans, mark 
 the place of the mechanical de- 
 scent of the marble ; whilst a da- 
 maged and rejected cylinder, appa- 
 rently intended for a pai't of a 
 column of the Parthenon, interests 
 the traveller on the ascent. 
 
 Penthouse, a projection over a door, 
 an entrance, a window, or a flight : 
 of steps, etc., for protection from ! 
 weather. 
 
 Peperino marble, in mineralogy, a ' 
 calcareous stone, something of the J 
 nature of travertino. It is supposed j 
 be the ancient Saxum Albanum, 
 of which the foundations of the 
 capitol at Rome (still to be seen) 
 were built. 
 
 Perambulator, in surveying, an in- 
 strument for measuring distances ; 
 named also the Pedometer and Sur- 
 veying wheel. 
 
 Perault's Estimation of Architects: 
 The little estimation in which 
 
PER 
 
 PERCLOSE. 
 
 PER 
 
 architects have been held in France 
 has prevented many from embra- 
 cing a profession to which so little 
 regard has been paid ; and those 
 whom the force of strong inclina- 
 tion has induced to adopt it, have 
 led their lives in obscurity, ex- 
 cluded from the company and con- 
 versation of men of rank and for- 
 tune. 
 
 Nor is it regard and honour 
 alone that nourish the arts. The 
 conversation of men of sense, learn- 
 ing, and fortune cannot be dis- 
 pensed with ; for an exquisite taste 
 is rarely formed among the vulgar, 
 and there are a thousand things 
 that cannot be learned in the con- 
 dition of a simple artisan, nor even 
 in schools, which however are ab- 
 solutely necessary in order to arrive 
 at excellence in the fine arts. 
 
 That haughtiness which some- 
 times attends the consciousness of 
 superior abilities, and disdain of all 
 mean and vulgar employments, was 
 carried to such excess among the 
 Romans, that many of them put 
 themselves to death rather than 
 work on buildings the structure of 
 which was not so excellent as to 
 render them distinguished. But 
 when good architecture began to 
 be honoured by that people, the 
 art was cultivated with such ardour 
 that in less than forty years it was 
 brought so its highest perfection. 
 For this it was not necessary to 
 send to Greece for masters. There 
 were many Romans capable of de- 
 signing and executing the boldest 
 and most magnificent works, and 
 many excellent volumes on ar- 
 chitecture were written by Fussi- 
 tius, Varro, Septimius Celsus, and 
 other learned men. Even the 
 Greeks employed Roman archi- 
 tects, and when King Antiochus 
 completed the Temple of Jupiter 
 Olympus at Athens, it was from 
 the designs and under the conduct 
 of Cossutius, a Roman citizen. 
 
 Such was the passion for magni- 
 ficent buildings, that the expense of 
 
 330 
 
 a private house was found to amount 
 amount to near two million pounds 
 sterling (50 millions French) ; and 
 in Edile caused to be built, in less 
 than one year, a theatre adorned 
 with 360 columns, of which those 
 in the lowest order were of marble, 
 and 38 feet high ; those of the se 
 cond order were of crystal, and 
 those of the third order of bronze 
 gilt. It is said that this theatre, 
 which was capable of containing 
 80,000 persons seated, was also 
 embellished with 3,000 statues of 
 bronze, and that this magnificent 
 building was erected to serve six 
 weeks only. 
 
 Historians relate that another 
 Edile built a fountain, upon the 
 aqueduct of which there were 130 
 towers (regards or chateaux}, and 
 the fountain adorned with 400 co- 
 lumns of marble a'nd 300 figures 
 in bronze. The water, which was 
 poured through 700 pipes, was re- 
 ceived into more than 100 basins. 
 
 Historians also remark that 
 among the laws made by the Ro- 
 mans to restrain profusion and 
 luxury, some of which were ex- 
 tremely severe, there is not one 
 that controls the expense of build- 
 ings. So great was the venera- 
 tion of this wise people for every 
 art that does honour to merit and 
 virtue, and which can preserve the 
 memory of them to posterity. 
 
 In France, as in all other coun- 
 tries which offer sufficient encou- 
 ragement, a talent for architecture 
 may no doubt be developed. Before 
 the reign of Francis I. the French 
 princes had so little taste for the 
 arts, that they regarded nothing 
 but what related to war. 
 
 Perch, a small projecting beam, cor- 
 bel, or bracket, near the altar of a 
 church. 
 
 Perch, or Pole, a linear measure of 
 5^ yards. 
 
 Perclose, an enclosure, a railing ; 
 sometimes used to protect a tomb, 
 or to separate a chapel from the 
 main body of the church. 
 
PER 
 
 PERPENDICULAR. 
 
 PER 
 
 Percussion, in mechanics, the striking 
 of one body against another, or the 
 shock arising from the collision of 
 two bodies. 
 
 Periacti, the revolving scenes of the 
 theatre, called scenes Versailles by 
 the Romans : they were placed be- 
 fore the itinera versurarum, or 
 those entrances to the stage which 
 were in the returns of the perma- 
 manent scene. 
 
 Periactos, a theatrical machine, con- 
 sisting of three scenes placed in 
 the form of a triangle on a revolv- 
 ing platform ; so that, by simply 
 turning the machine, the scene 
 could be changed. 
 
 Pericles caused to be erected at 
 Athens the famous statue of Mi- 
 nerva, of gold and ivory. Pausanias 
 says, she stood erect, her garments 
 reaching to her feet ; she had a hel- 
 met on, and a Medusa's head ; inone 
 hand she held a spear, and on the 
 other stood a Victory, of 4 cubits 
 high. Pliny tells us the statue 
 was 26 cubits high (37 ft. 8 in.), in 
 which he perhaps included the 
 pedestal, whereon they both say 
 the birth of Pandora was repre- 
 sented. We are not told whether 
 the ivory was painted ; but by what 
 Strabo says, that Panaenus, the 
 brother or nephew of Phidias, as- 
 sisted him in colouring the statue 
 of Jupiter at Elis, which was like- 
 wise of ivory and gold, it probably 
 was. The reason why ivory was 
 used in statues of this kind, ra- 
 ther than wood, seems not to have 
 been on account of its colour, but 
 because wood is apt to crack, and 
 to be destroyed by worms : but 
 ivory is not of uniform colour, 
 being yellow near the outside of the 
 tooth, and white in the middle ; it 
 therefore would require painting on 
 that account, and likewise to hide 
 the joining of the pieces. Thucy- 
 dides says the gold about it weighed 
 40 talents, which, according to the 
 value of gold at that time, was 
 worth about 120,000 sterling. 
 
 Peridromus, in ancient architecture, 
 
 331 
 
 the space of an aisle in a peripte- 
 ron, between the columns and the 
 wall, used for walks by the Greeks. 
 
 Perimeter, the boundary of any figure, 
 being the sum of all the sides in 
 right-lined figures, the same as cir- 
 cumference or periphery in those of 
 a circular form. 
 
 Periphery, the circumference of a 
 circle or ellipse. 
 
 Peripteral, a temple which had its 
 cella surrounded by columns. 
 
 Peristylium, a continued row or se- 
 ries of rows of columns all round 
 a court or building, in contradis- 
 tinction to porticoes, in which the 
 pillars did not surround a space, 
 but were arranged in one or more 
 parallel lines. 
 
 Peritrochium, in mechanics, a wheel 
 or circle concentric with the base 
 of a cylinder, and movable toge- 
 ther with it about an axis : the axis, 
 with the wheel and levers fixed in 
 it, to move it, constitute that me- 
 chanical power called axis inperi- 
 trochio. 
 
 Perpendicular, in geometry, a line 
 crossing or cutting the horizon or 
 any other line at right angles. 
 
 Perpendicular : one line is perpendi- 
 cular to another when it makes the 
 angles on each side of it equal to 
 each other. 
 
 Perpendicular Style of Gothic Archi- 
 tecture, derived from the Decora- 
 ted about the end of the fourteenth 
 century, and continued till the 
 middle of the sixteenth : it is so 
 called from its tracery consisting 
 of perpendicular lines, and forming 
 one of its most striking features. 
 Many fine examples yet exist in 
 England. The perpendicular cha- 
 racter of the style is exhibited in 
 the window tracery, where the 
 transoms cross the mullions at right 
 angles ; and in large windows these 
 are occasionally repeated several 
 times : bands, quatrefoils, and other 
 ornaments are more frequently 
 employed than in the other styles, 
 and are often carried across the 
 panellings and vertical lines, ere- 
 
PER 
 
 PERSIAN ARCHITECTURE. 
 
 PEW 
 
 ating a rectilinear arrangement, 
 pervading most of the subordinate 
 parts, that gives a peculiar air and 
 stiffness. Panelling is used most 
 abundantly on walls, both inter- 
 nally and externally, and also on 
 vaulting. Some fine examples of 
 this style are drawn in Mr. Parker's 
 'Glossary,' in 2 vols. 
 
 Perpent-stone, a bond-stone ; a large 
 stone reaching through a wall so 
 that it appears on both sides of it. 
 
 Perpetual motion is that which pos- 
 sesses within itself the principle of 
 motion. 
 
 Perron, in architecture, a staircase 
 outside of a building, or the steps 
 in front of a building leading up to 
 the first story. 
 
 Persian Architecture. Honshung, the 
 grandson of Kaiomurs, the founder 
 of the Paishdadian dynasty, is fa- 
 mous in Persian history as the first 
 who constructed aqueducts. These 
 aqueducts are made by a succession 
 of small wells a few yards from 
 each other, and of such depth as 
 the level and soil require. They 
 are connected with each other at 
 the bottom by a channel, large 
 enough for a man to pass to clear 
 it. These wells commence at a 
 spring, and not only convey its 
 waters, but that of such other 
 springs as are found in the course 
 of the canal. They are common 
 through all Persia : the water they 
 convey is applied to irrigation. 
 
 Gushtasp (Darius Hystaspes), in 
 whose reign the Persians became 
 worshipers of fire, ordered 12,000 
 cowhides to be dressed fine, that 
 the precepts of this new faith might 
 be written upon them. These 
 parchments were deposited in a 
 vault hewn out of the rock at Perse- 
 polis. Some vaults answering this 
 description are still seen in the ruins 
 of that city. 
 
 The celebrated hall called Chehel 
 Minar, or Hall of Forty Pillars, was 
 built, it is said, by Homai, queen of 
 Persia, the daughter of Artaxerxes 
 Longimanus. 
 
 332 
 
 Dara, in Mesopotamia, was 14 
 miles from Nisibis, and four days' 
 journey from the Tigris. It had 
 two walls at the distance of 50 
 paces : this space was for the cattle 
 of the garrison. The fortifications 
 were walls or curtains, defended by 
 towers ; in the towers arid walls 
 were loopholes and galleries for the 
 besieged. It had ditches, which 
 were filled with water at pleasure 
 from the river. 
 
 In 638, A.H. 17, the foundations 
 of Bussorah were laid by the Arab 
 chief, Alabah Ghuzwan. 
 
 Persian Wheel, a name given to a 
 machine for raising water, which 
 may be turned by means of a 
 stream acting on and turning 
 round the wheel. The buckets, 
 instead of being firmly fastened, 
 are hung upon the wheel by strong 
 pins, fixed in the side of the rim, 
 which must be made as high as 
 the water is intended to be raised 
 above the level of that part of 
 the stream in which the wheel is 
 placed. 
 
 Persians, in ancient architecture, 
 male figures employed to support 
 entablatures ; the female figures 
 were named Caryatides. 
 
 Perspective, in painting, etc., the 
 science by which all things are 
 ranged on a plane surface, as in a 
 picture, according to their appear- 
 ance in their real situation. 
 
 Pew, an enclosed seat in a church, in- 
 troduced since the Reformation. 
 Previous to the Reformation the 
 nave of a church was the part oc- 
 cupied by the congregation. Pews 
 are fixed seats, separated from each 
 other by wainscoting, and varying 
 in height. 
 
 Pewter, in metallurgy, a mixed metal, 
 consisting of tin variously alloyed 
 with lead, zinc, bismuth, or anti- 
 mony. Common low-priced pewter 
 contains 20 parts tin, 3 lead, 1 brass; 
 best pewter, 17 parts antimony, 
 100 parts tin, and a little copper. 
 Pewter dishes and wooden tren- 
 chers were the ordinary services 
 
PHA 
 
 PHOTOGRAPHY. 
 
 PIL 
 
 of our ancestors till the time of 
 Elizabeth, when " by reason of 
 sharpe laws provided in that behalf," 
 pewter was compounded of purer 
 metal than before. The splendid 
 services of gold and silver were 
 only used on occasions of ceremony 
 and on festivals. 
 
 Pharos or Pharus, a lighthouse. The 
 most celebrated lighthouse of an- 
 tiquity was that situated at the 
 entrance of the port of Alexandria, 
 built by Sostratus on an island, 
 by the direction of Ptolemy, at a 
 cost of 800 talents. Pliny mentions 
 the lighthouses of Ostia and Ra- 
 venna. The name of Pharos was 
 given in allusion to that of Alex- 
 andria, which was the model for 
 their construction. 
 
 Phidias, the great Greek sculptor and 
 director of the works under Pericles. 
 
 Phonics, the doctrine of sounds, 
 otherwise named acoustics. 
 
 Phosphate of iron is a native ochre, 
 which classes in colour with the 
 deeper hues of ultramarine ashes, 
 and is eligible for all their uses. 
 (See Blue Ochre.) Slate-clays and 
 several native earths class with 
 greys; but the colours of some of 
 the latter, which have been tried, 
 are not durable, being subject to 
 become brown by the oxidation of 
 the iron they contain. 
 
 Photography, a new art, the produc- 
 tion of pictures from nature's 
 image. Photography presents a 
 number of the most interesting 
 phenomena, which have acquired 
 important practical results, in cor- 
 rectly portraying by the light of 
 day all things in nature, whether 
 architecture, drawings of every va- 
 riable kind, landscape, machinery, 
 pictures in oil, the human form, 
 etc. The aids for the accomplish- 
 ment of the art is by chemical 
 agency either on glass, paper, ivory, 
 stone, and by the lenses of the ca- 
 mera obscura. Various valuable 
 works have been published descrip- 
 tive of the whole process. (See 
 Weale's ' Rudimentary Series.') 
 
 329, P 
 
 Physics, the doctrine of natural 
 bodies, their phenomena, causes, 
 and effects, with their various mo- 
 tions, operations, affections, etc. 
 Taken in its most enlarged sense, 
 it comprehends the whole study 
 of nature, and includes physiology 
 and natural history. 
 
 Piazza, an open area or square ; a 
 covered walk or portico. 
 
 Pick, an instrument in common use 
 as well in agricultural as in mining 
 operations. 
 
 Pictura (Latin), a painting. The art 
 of imitating the appearances of 
 bodies upon ah even surface, by 
 means of light and shade, or co- 
 lour, was most extensively cultiva- 
 ted by the ancients, but especially 
 by the Greeks, amongst whom it 
 was carried to the highest degree of 
 technical development. 
 
 Pier, in architecture, the strong co- 
 lumns on which the arch of a 
 bridge is raised. 
 
 Pier, the solid mass between doors, 
 windows, and other openings in 
 buildings : the term is often ap- 
 plied to pillars in Norman and 
 Gothic architecture. 
 
 Piers, walls built to support arches,and 
 from which, as bases, they spring. 
 
 Pilce, square blocks placed upon the 
 epistylia, and immediately over the 
 columns in a basilica, for supporting 
 the timbers of the roof. Pilffi were 
 also buttresses built against the 
 walls of a mole, to resist the force 
 of the waters. 
 
 Pilaster, in architecture, a square 
 column, sometimes insulated, but 
 more frequently set within a wall, 
 and only showing a fourth or fifth 
 part of the thickness. Pilasters 
 were unknown in Greek archi- 
 tecture, in which only anta3 (see 
 A ntce) were admitted : they are 
 employed by the moderns as sub- 
 stitutes for an order in engaged 
 columns, and are, perhaps, even 
 preferable to the latter, inasmuch 
 as they combine better and more 
 naturally with the wall to which 
 they are attached. 
 
 a 
 
PIL 
 
 PILES. 
 
 PIL 
 
 Piles, as applied in engineering Ope- 
 rations, are used both in temporary 
 and in permanent constructions. 
 In the former cases, they are com- 
 monly squared logs or baulks of 
 timber, which are driven close to- 
 gether in single or double rows, so 
 as to enclose a space of water, and 
 form a cofferdam, from which the 
 water is subsequently pumped out, 
 and thus a dry space obtained for 
 laying the foundations of piers, 
 abutments,etc.,in bridges and other 
 similar works. The most substan- 
 tial kind of coffer-dam, adapted for 
 works which will be long in con- 
 struction, is formed of a double row 
 of concentric piling, a space of three 
 or more feet being left between the 
 two rows of piles, which is filled 
 with clay, well puddled or rammed 
 in. For permanent works, piles 
 are driven in loose or uncertain 
 strata in rows, leaving a space a 
 few feet in width between them, 
 and upon the heads of the piles the 
 foundations of the superstructure 
 are erected. In some of the iron 
 bridges lately erected for railways, 
 piles have been used as substitutes 
 for solid piers in the water. Wharf- 
 walls have also been built with 
 facings formed with piles. In most 
 of these works the piles used are 
 of cast iron, while those used for 
 cofferdams and foundations are of 
 timber, the lower end being fitted 
 with a wrought-iron pointed shoe, 
 to facilitate the penetration of the 
 strata, and the head of the pile 
 guarded with a ring of the same 
 metal to prevent its splitting while 
 being driven. Iron piles are cast 
 in various forms ; sometimes so as 
 to preserve similar external dimen- 
 sions to timber piles, and hollow or 
 tubular within ; and if for wharf- 
 walls, they are formed with grooves 
 in the sides, into which metal plates 
 are fitted, the piles being placed 
 from 4 to 7 feet apart, and the in- 
 termediate spaces filled up with 
 these plates. 
 
 For piling in loose and movable 
 
 materials, and more especially for 
 forming moorings, Mr. Mitchell has 
 introduced a form of pile which is 
 properly called a screw-pile, the 
 lower end being formed as a screw, 
 and fitted (for moorings) with a 
 broad plate or disc of metal in a 
 spiral or helical form. The most 
 important purpose to which the 
 screw-pile has been applied is for 
 forming the foundations of light- 
 houses, beacons, jetties, etc., in 
 places where the sand or soil is too 
 unstable to bear the weight of any 
 massive structure, or where the 
 force of the waves would endanger 
 masses of masonry by undermining 
 the materials below them. The 
 lighthouse erected in the year 1840 
 upon the Maplin Sands may be in- 
 stanced as a work which owes the 
 very possibility of its existence to 
 these screw-pile foundations. The 
 piles used in this structure are nine 
 in number, and made of malleable 
 iron, 5 inches in diameter and 26 
 feet long, with a cast-iron screw 
 4 feet in diameter, screwed to the 
 foot of each. Eight of the piles 
 were placed at the angles of an 
 octagon, and the ninth in the cen- 
 tre, and were put down in nine 
 consecutive days, being screwed to 
 a depth of 22 feet in the bank. 
 Several similar works have been 
 since constructed with complete 
 success ; and in 1847, the screw- 
 piles were applied in the construc- 
 tion of a jetty 260 feet in length 
 beyond the old one, at Courtown, 
 on the coast of Wexford. Mallea- 
 ble-iron piles, 5 inches in diameter, 
 and laid in the ground 11 to 15 
 feet, were fitted with screws 2 feet 
 in diameter. The facility and ra- 
 pidity with which these piles are 
 inserted are not the least among 
 their qualifications. 
 
 Before the introduction of screw- 
 piles, the process of fixing which 
 consists in giving them a rotatory 
 motion by means of capstans, the 
 fixing of piles was accomplished by 
 driving them downwards by the 
 
PIL 
 
 PILES. 
 
 PIL 
 
 force of an adequate weight, which 
 was permitted to fall vertically on 
 them from a considerable height. 
 The machinery employed was 
 therefore properly called a pile- 
 driver^ and consisted simply of a 
 vertical framing, provided with 
 winches and chains, hy which the 
 weight or ' monkey' was alter- 
 nately raised hy manual power, 
 and released so as to fall upon 
 the head of the pile ; or a gin was 
 applfed, and horses used for the 
 same purpose. 
 
 Within the last few years a great 
 improvement has been effected in 
 the machinery for pile-driving, by 
 the application of steam power. 
 The earliest invention for this pur- 
 pose is recorded in a patent granted 
 in 1806, but no practical applica- 
 tion appears to have resulted for 
 many years. The patent referred 
 to was dated June 6, 1806, and 
 granted to William Deverell, for 
 " improvements in the mode of 
 giving motion to hammers, stamp- 
 ers, knives, shears, and other things, 
 without the application of wheels, 
 pinions, or any rotative motion, by 
 means of various powers now in 
 common use." The apparatus was 
 designed to consist of a steam- 
 cylinder with piston and rod, and 
 a hammer, raised by admitting the 
 steam below the piston. By the 
 condensation or the escape of the 
 steam, the hammer and the piston 
 were allowed to descend, urged 
 both by their own weight and by 
 the elasticity of the compressed air 
 in the top of the cylinder above the 
 piston. This, therefore, established 
 the principle of the steam-hammer : 
 but the most successful application 
 of it to the purposes of driving 
 piles, as well as to those of the 
 smithery, is due to Mr. James 
 Nasmyth, whose steam - hammer 
 consists of a steam-cylinder, which 
 is closed at the bottom, but has 
 openings in the top, to admit the 
 passage of air. The rod of the 
 piston passes through a steam-tight 
 
 335 
 
 aperture in the bottom of the cy- 
 linder, and has the ' monkey,' or 
 driver, weighing 2^ tons,suspended 
 from it. The machine is worked 
 with high-pressure steam, which, 
 entering the bottom of the cylinder, 
 raises the piston and ' monkey.' 
 When the piston reaches the height 
 intended, it shuts the induction 
 and opens the eduction pipe (also 
 at the bottom of the cylinder), by 
 which the steam escapes, and the 
 monkey falls. A heavy iron cap 
 slides between standards and round 
 the head of the pile, and thus guides 
 it in its descent. This machine, as 
 used at Devonport, in driving piles 
 for the steam-dock, made seventy 
 strokes per minute, and drove piles 
 14 inches square and 18 feet in 
 length. 
 
 In the year 1843 (Decembers), 
 a patent was obtained by Dr. L. H. 
 Potts, for " improvements in the 
 construction of piers,embankments, 
 breakwaters, and other similar 
 structures." The several objects 
 comprised in this invention were 
 sought with considerable ingenuity, 
 and have been realized with suc- 
 cess. The invention includes the 
 application of hollow piles of iron, 
 of a cylindrical or other convenk at 
 form, and sinking them by with- 
 drawing the sand, etc., within them 
 by the action of an air-pump. For 
 this purpose the pile is fitted with 
 an air-tight lid, through which a 
 pipe passes to connect the interior 
 of the pile with a receiver. The 
 receiver is connected by a pipe 
 with a three-barrelled air-pump, by 
 working which the air is exhausted 
 from the hollow pile, and the sand 
 and water raised into the receiver, 
 which is emptied as often as neces- 
 sary. A second purpose proposed 
 in this patent is the use of skeleton 
 frames or cases of cast-iron in con- 
 nection with the piles, for securing 
 them together, and preserving their 
 relative positions. A third object 
 is the injection, by'hydraulic pres- 
 sure, of such chemical solutions 
 
'IL 
 
 PILE-ROAD. 
 
 PIE 
 
 about the feet of the piles as will 
 consolidate the sand upon which 
 they stand, and thus secure the 
 work. And the inventor also pro- 
 posed to use hydraulic cements in 
 a dry state, delivered at the base 
 of the piles, by the admixture of 
 which cements with the water they 
 would become solidified, and thus 
 materially aid in strengthening the 
 superstructure. 
 
 Recently these piles have been 
 successfully used on the Goodwin 
 Sands, by the Trinity Board. Pre- 
 viously, engineers had been baffled 
 in finding a bottom. The piles have 
 now been fairly affixed to the hard 
 bottom, seventy-five feet through 
 the sand. 
 
 In connection with Mitchell's, 
 Nasmyth's, and Potts's modes of 
 piling, it is proper to notice also 
 Cram's patent pile-driving locomo- 
 tive machine, which was successful 
 in its operation in the United States. 
 The volume (' Ensamples of Rail- 
 way-Making') from which the fol- 
 lowing extract has been made was 
 edited by the publisher of this 
 Dictionary, with a view to induce a 
 cheaper mode of construction of 
 railways in countries less wealthy 
 than those already intersected by 
 iron roads. 
 
 Pile-road. As a considerable 
 length of the Utica and Syracuse 
 railroad passes through a deep 
 swamp, a foundation of great per- 
 manency was required : this gave 
 rise to a modification of the super- 
 structure, and formed that which 
 is known as pile-road. The swamp 
 varied in depth from 10 feet to 60 
 feet, and was nearly on a dead level 
 throughout : the grude-line closely 
 corresponded with its surface ; so 
 that it was necessary to reach the 
 hard bottom before any founda- 
 tion could be effected. Piles were 
 adopted as the cheapest and most 
 efficacious means to secure a dura- 
 ble and substantial basis: they 
 were driven to their places by a 
 steam pile-driver. This was a ma- 
 
 336 
 
 chine formed of a platform about 
 25 feet long and 8 feet broad : at 
 one end were erected two pairs of 
 leaders or guides, in which the 
 hammers moved. Immediately be- 
 hind the leaders were fixed the 
 rollers, with the necessary brakes 
 and gearing for working the ham- 
 mers, raising the piles, etc. The 
 rollers were revolved by a small 
 high-pressure steam-engine, occu- 
 pying the rear of the machine. The 
 arrangement of the leaders was the 
 same as in ordinary pilingmachines: 
 a curved piece of wood forced open 
 the sheers when the hammers 
 reached their elevation. The ham- 
 mers were confined to the leaders 
 by a groove : they weighed about 
 l,0001bs. each, were made of cast- 
 iron, and at their last blow fell 
 through a space of 27 feet. A pair 
 of piles were driven at one opera- 
 tion by this machine ; when driven, 
 cast-iron rollers were placed upon 
 their heads, and the machine, by 
 means of an inverted rail, moved 
 on to the next place. The heads 
 of the piles, sawed off to reduce 
 them to the proper level, were 
 found sufficient to supply the fur- 
 nace with fuel. 
 
 The men employed in operating 
 the machine were, a foreman, a 
 steam engineer, two brake-men,anrl 
 two men in front at the saws ; also 
 a horse and cart, to furnish water 
 for the boiler. Properly geared in 
 front of the machine, and between 
 the leaders, was a saw that player! 
 on a sway-bar and could be pressec 
 against either pile as it was driven 
 home. The machine was manu 
 factured complete for the cost of 
 400. 
 
 Each pile was prepared for being 
 driven by simply sharpening one 
 end to a point, and squarely butt- 
 ing the other ; it was drawn up by 
 ropes worked by the engine, se- 
 cured in position between the 
 leaders, and driven to the hard 
 bottom. Generally the piles mani- 
 fested no disposition to split : when 
 
PIL 
 
 PISCINA. 
 
 PIS 
 
 they did, their heads were encom- 
 passed with an iron hoop. When 
 the pile was not of sufficient length 
 to reach the hard bottom, another 
 was dowelled upon its head, and 
 this was repeated as often as ne- 
 cessary. The piles were charred, 
 to increase their durability ; and an 
 auger-hole, bored in their heads for 
 the purpose, was filled with salt, 
 and securely plugged up. 
 
 Pillar, a kind of irregular column, 
 round and insulate, but deviating 
 from the proportion of a just co- 
 lumn. The term pillar is more 
 usually applied to Gothic archi- 
 tecture than to the Classical, the lat- 
 ter being governed by the rules of 
 proportion : not so with the Gothic 
 pillar, it being subject to no fixed 
 rules. 
 
 Pillars (monumental], columns raised 
 for the commemoration of events, 
 a practice from remote antiquity. 
 " Jacob set a pillar upon her grave: 
 that is the pillar of Rachel's grave 
 unto this day." (Gen. xxxv. 20.) 
 
 Pillars, in ship-building, pieces fixed 
 under the middle of the beams, to 
 support the decks. 
 
 Pillion, the tin that remains in the 
 slags after it is first melted. 
 
 Pinacotheca, a picture gallery. The 
 public gallery at Munich is called 
 the PinakotheJc. 
 
 Pindrill, a drill used for cutting a 
 recess for a bolt-head, or for en- 
 larging a hole. 
 
 Pines and Firs are cone - bearing 
 timber-trees which thrive best in 
 cold climates : they are of great 
 variety, and the general uses of 
 the wood are innumerable, besides 
 those for ships and house car- 
 pentry. Its use in England is 
 most extensive: it is principally 
 imported from America, Norway, 
 the Baltic, Memel, Riga, Dantzic, 
 etc. 
 
 Pinion, in mechanics, an arbour or 
 spindle, in the body of which are 
 several notches, into which the 
 teeth of a wheel catch, that serves 
 to turn it round; it is also the 
 
 337 
 
 name of a lesser wheel that plays 
 in the teeth of a larger one. 
 
 Finite, a micaceous mineral. 
 
 Pink, in navigation, a name given to 
 a ship with a very narrow stern. 
 
 Pinnacle, an ornament placed on the 
 top of a buttress as a termination 
 to an angle or gable of a house, 
 church, or tower; also a summit 
 or lofty apex. 
 
 Pins, in ships, are fixed in the drum- 
 heads of capstans, through the 
 ends of the bars, to prevent their 
 unshipping; sometimes put through 
 the bolts to belay a rope, and 
 called belaying pins; and some- 
 times the main bolts are called 
 bolt-pins. 
 
 Pipe, a tube for the conveyance of 
 water, gas, or steam, of various 
 dimensions and uses. 
 
 Pipe, in mining, a running vein, 
 having a rock root and sole. 
 
 Piscina. Pliny says the Romans 
 adorned the walls, ceilings, and 
 floors of their baths. It was on 
 the piscina they bestowed the most 
 art. In the baptisterium they 
 dipped their whole .body, and this 
 was large enough to swim in ; but 
 when they were disposed to swim at 
 large in warmer water, they en- 
 tered the piscina, a basin so called, 
 as its size bore some resemblance 
 to a pond. When the thermae were 
 built, they were made to contain 
 lakes of warm water: the water ac- 
 quired its heat by passing through 
 the fire in a brass pipe, and 
 must have been more or less hot 
 according to the length of its pro- 
 gress. 
 
 Piscina, a shallow stone basin, or 
 trough, with a hole in the bottom, 
 formerly placed near to the altar 
 in Roman Catholic churches, and 
 fixed at a convenient height above 
 the floor,to hold the water in which 
 the priest washed his hands; also for 
 rinsing the chalice at the time of 
 the celebration of the mass. It was 
 usually on the right-hand side, on 
 the approach to the altar. 
 
 Pise, a peculiar mode of forming 
 
PIS 
 
 PISTON. 
 
 PLA 
 
 buildings, particularly those* for 
 cottages and farming purposes, with 
 some sort of stiff earthy materials 
 of a loamy quality. The earth so 
 collected, framed, is well rammed 
 until the moisture is driven out, and 
 used to make the walls or sides of 
 the building, instead of bricks. It 
 has been used with much economy 
 and success on the Continent, and 
 in some parts of England. 
 
 Pistici, or Pastici, a term by which 
 Italians distinguish pictures which 
 cannot be called either original or 
 copies, being the works of some 
 artists who have had the skill to 
 imitate the manner of design and 
 colouring of other eminent masters; 
 sometimes borrowing part of their 
 pictures, sometimes imitating their 
 touch, their style of invention, 
 their colouring, and expression. 
 Several painters, of considerable 
 reputation for their own original 
 performance, have made themselves 
 remarkable in this way ; but none 
 of them more thanj)avid Teniers, 
 who so successfully counterfeited 
 Giacopo Bassan, as to deceive the 
 most judicious, in many instances, 
 at the first sight ; though, upon a 
 closer inspection, his light and easy 
 pencil, and a predominant grey tint, 
 which is observable in the colour- 
 ing of that master, show a percep- 
 tible difference between his pencil 
 and colouring, when they are care- 
 fully examined and compared with 
 Bassan's. (See Pastici.) 
 
 Piston, a movable air-tight division 
 within the steam-cylinder, acted 
 upon by the steam. Pistons are 
 either metallic or packed. Metal- 
 lic pistons usually have segments 
 of brass or cast-iron, called junk- 
 rings, pressed outward by springs. 
 Packed pistons ar surrounded by 
 well-greased hemp. 
 
 Piston-rod, the rod fixed to the piston, 
 to communicate its motion to the 
 crank. 
 
 Pitch, in building, the vertical angle 
 of a roof, or the proportion between 
 the heights and spans, as when the 
 
 height is one-fourth, one-third, or 
 one-half, of the breadth of the 
 building. If the height is one-half 
 of the breadth, the inclination of 
 the planes, forming the vertical 
 angle, is a right angle. 
 
 Pitching -piece, in staircasing, a ho- 
 rizontal piece of timber having one 
 of its ends wedged into the wall, at 
 the top of a flight of steps, to sup- 
 port the upper ends of the rough 
 strings. 
 
 Pitch-wheel. When two toothed- 
 wheels work together, the circles 
 of contact are called the propor- 
 tional circles, or pitch circles. 
 
 Pit-man, one employed to look after 
 the lift of pumps and the drainage. 
 
 Pit-work, the pumps and other ap- 
 paratus of the engine shaft. 
 
 Pivot, a stud or small pin on which 
 anything turns. 
 
 Pix, in church rituals, a little chest 
 or box, in which the consecrated 
 host is kept. 
 
 Plain chart, in navigation, is a sea- 
 chart, wherein the meridian and 
 parallels are straight parallel lines, 
 as in Mercator's projection; con- 
 sequently the degrees of longitude 
 are the same in all latitudes. 
 
 Plain sailing, in navigation, the art of 
 working a ship's motion on a plain 
 chart, which supposes the earth to 
 be an extended plane, or flat, and 
 not globular. 
 
 Plan. The plan of a building may be 
 familiarly described as an archi- 
 tectural map; therefore only those 
 who cannot comprehend a geogra- 
 phical or topographical map can 
 be at any loss to understand an 
 architectural one, the latter being 
 precisely of the same nature as the 
 others, with this difference in its 
 favour, that it is much less con- 
 ventional. To define it more ex- 
 actly, a plan is a horizontal sec- 
 tion supposed to be taken on the 
 level of the floor through the solid 
 parts of the fabric walls, co- 
 lumns, etc., so as to show their va- 
 rious thicknesses and situations, 
 the dimensions of the several spaces 
 
PLA 
 
 PLANING MACHINE. 
 
 PLA 
 
 or rooms, the position of the doors 
 by which they communicate with 
 each other, and various particulars 
 that cannot otherwise be explained. 
 Studying buildings without plans, 
 is like studying geography without 
 maps. A plan frequently costs the 
 architect more study than all the 
 rest of his design, and much mis- 
 taken are those who suppose that 
 convenience alone has chiefly to 
 he considered. Convenience is, of 
 course, or ought to be, made a sine 
 qua non; yet it is not so much a 
 positive merit in itself, as the want 
 of it is a positive defect. Mere 
 convenience is not an artistic qua- 
 lity : from that to beauty of plan, 
 to striking combinations, and 
 studied effects, and varied play of 
 arrangement, the distance is very 
 great. A commonplace plan is hut 
 a very dull, uninteresting affair : it 
 is no more than what any builder 
 can accomplish ; but. a plan replete 
 with imagination, piquant play, and 
 well-imagined contrasts, is no every- 
 day matter. 
 
 Planceer, the soffit or underside of 
 the corona of a cornice, in Classical 
 architecture. 
 
 Plane, in surveying, a level surface, 
 parallel to the horizon. In car- 
 pentry, an instrument by which the 
 surfaces of bodies are smoothed. 
 
 Plane, inclined: in mechanics, this 
 resembles one half of a wedge that 
 has been cut in two parts length- 
 wise. 
 
 Plane, in geometry, a plain level 
 figure, or a surface lying evenly 
 within its boundary lines. 
 
 Planing Machine, an invention for 
 diminishing the great labour of 
 planing the surfaces of planks and 
 boards of wood, and for reducing 
 the surface to a true and smooth 
 face, by means of planes, or instru- 
 ments of a similar nature, which 
 are actuated by the power of the 
 machinery instead of the strength 
 of a man's arm. 
 
 Planing Machine. The invention of 
 the ' slide-rest,' which has effected 
 
 such an important improvement in 
 cylindrical and conical turning, has 
 been of far superior advantage in 
 its application to the planing of 
 surfaces, as the planing machine is 
 but the slide-rest applied to a tra- 
 versing table. In planing machines 
 of the ordinary construction, the 
 bed or basement frame has two 
 angular ridges from end to end, 
 one on each side, which fit into 
 corresponding angular grooves in a 
 traversing table. This table rests 
 upon the ridges, and is moved 
 backwards and forwards by a 
 screw-rack and pinion, or chain : 
 its surface is accurately planed, and 
 the work being fastened upon it 
 partakes of its motion, and is con- 
 strained to move in a perfectly 
 straight line. Over the traversing 
 table, at the centre of the machine, 
 is fixed a slide-rest, which is held 
 fast by being bolted to two upright 
 standards fixed to the bed, one on 
 each side. The horizontal slide has 
 another at right angles to it, which 
 serves to hold the cutting-tool and 
 adjust it to the work, so as to take 
 a cut more or less deep, as required. 
 To the long screw of the horizon- 
 tal slide, mechanism is connected 
 which causes it to advance the 
 vertical slide and tool a very small 
 distance across the machine, just 
 before the commencement of each 
 forward movement of the table ; so 
 that by a repeated series of move- 
 ments to and fro of the table, the 
 tool is made to traverse the whole 
 surface of the work ; and thus, by 
 the perfectly level movement of the 
 table in the one direction, and that 
 of the slide in the other, a per- 
 fectly plane surface is obtained. In 
 some machines the table is made 
 to travel backward at a much faster 
 rate than in the forward motion, so 
 as to save time ; and in others, the 
 cutting tool acts in both move- 
 ments, by being turned at the end 
 of each. 
 
 Planish, in carpentry, etc., to smoothe, 
 to polish. 
 
PLA 
 
 PLATE. 
 
 PLA 
 
 Planisher, a thin flat-ended tool, used 
 by turners for smoothing brass- 
 work. 
 
 Planisphere, in geometry, etc., a 
 sphere projected on a plane ; such 
 are maps of the heavens or of the 
 earth. 
 
 Plank, a term applied to all super- 
 ficial timber which is 4 inches thick 
 and under,except 1 -inch, and some- 
 limes 1^-inch, which come under 
 the denomination of board. 
 
 Plank-sheers, in ship-building, pieces 
 of plank laid over the timber heads 
 on the quarter-deck, forecastle, and 
 round-house. 
 
 Plane-tree, a native of Europe; it is 
 also abundant on the banks of the 
 Mississippi and Ohio. This, per- 
 haps one of the largest of the Ame- 
 rican trees, is sometimes twelve 
 feet in diameter, and is much used 
 in that country for quays. It is 
 used here for musical instruments, 
 and other works requiring a clean, 
 light-coloured wood. 
 
 Plasm, in the arts, a mould ; a matrix 
 in which anything is cast or formed. 
 
 Plaster of Paris, in mineralogy and 
 the arts, gypsum deprived of its 
 water by burning, and reduced to 
 a white powder, which is afterwards 
 mixed with water. It serves many 
 purposes in building, and is used 
 likewise in sculpture, to mould and 
 make statues, basso-relievos, and 
 other decorations in architecture. 
 It is dug out of quarries in several 
 parts of the neighbourhood of Pa- 
 ris, whence its name. The finest is 
 that of Montmartre. It is known 
 also as gypsum. 
 
 Plastering, the art of covering the 
 walls and ceilings of a house or 
 other edifice with a composition, 
 of which the groundwork is lime 
 and hair mortar, finished with a 
 coating of finer materials. 
 
 Plat, in mining, ground appropriated 
 to ore or deads. 
 
 Plat-band, a flat fascia,band, or string, 
 whose proportion is less than its 
 breadth ; the lintel of a door or 
 window is sometimes so named. 
 
 Plate, and other services for the ta- 
 ble. In the time of Henry VIII. 
 and Elizabeth, amongst the nume- 
 rous costly and magnificent articles 
 for the table, wrought in silver, 
 gold, and other precious materials, 
 were chargers, dishes, plates, por- 
 ringers, saucers, vases or cups, pots 
 or tankards, flagons, pitchers, pot- 
 tels, ewers, creuses, bowls, goblets, 
 basins, washing-basins and ewers, 
 horns, cups for caudle cruets, spice- 
 plates, spiceries, salt-cellars, pep- 
 per-boxes, spoons and candlesticks. 
 
 Plate, a term applied to horizontal 
 timbers, placed on walls, etc., to 
 receive other timberwork : that at 
 the top of a building immediately 
 under the roof is a wall-plate; those 
 also which receive the ends of the 
 joists of the floors above the ground- 
 floor are called the same. 
 
 Plate-bending Machine. This inven- 
 tion was contrived for bending 
 plates of metal into any required 
 curve, and is particularly useful in 
 the construction of boilers and the 
 buckets of waterwheels : it con- 
 sists of two sideframes, which carry 
 three iron rollers and the spur- 
 wheels and pinions necessary to 
 communicate motion to two of 
 them, one of which is placed im- 
 mediately over the other, und can 
 be raised or lowered by screws to 
 the thickness of the plate to be 
 bent. The third roller is placed 
 behind the first two, and it is the 
 height of this roller, with respect 
 to that of the other two, that de- 
 termines the degree of curvature 
 of the plate : it is therefore made 
 capable of adjustment by set- 
 screws, and being placed to the 
 proper height, and the machine set 
 in motion, the plate is passed be- 
 tween the first two rollers, till, 
 coming in contact with the third, 
 it rises upward and takes the form 
 of a curve. 
 
 Platina yellow, is, as its name im- 
 plies, a preparation from platina, 
 which affords a series of yellow 
 pigments, the deep colours of which 
 
PLATINUM. 
 
 PLU 
 
 resemble the Terra di Siena, but 
 are warmer in tone and richer in 
 colour and transparency, much re- 
 sembling fine gall-stones, for which 
 they are valuable substitutes. They 
 work well, and are permanent both 
 in water and oil, when carefully 
 prepared ; but any portion of pal- 
 ladium in the metal from which 
 they are prepared neutralizes their 
 colour arid renders them useless. 
 
 Platinum is found in the metallic 
 state alloyed with other metals, 
 but not in large quantities. It 
 is not so white a metal as silver, 
 but is very malleable and ductile, 
 either when hot or cold. No fur- 
 nace can melt it ; but by the oxyhy- 
 drogen blow-pipe, or by a voltaic 
 current, it is capable of being fused, 
 and may be dissipated in the air. 
 Alone it is insoluble in nitric acid, 
 but when alloyed with other metals 
 it is soluble. 
 
 Plenum, in physics, a term used to 
 signify that state in which every 
 part or space of extension is sup- 
 posed to be full of matter. It is 
 used in opposition to vacuum. 
 
 Plinth, a square member forming the 
 lower division of the base of a co- 
 lumn, etc. ; also the plain project- 
 ing face at the bottom of a wall, im- 
 mediately above the ground. In 
 Gothic architecture the plinth is oc- 
 casionally divided into two stages, 
 the tops of which are either splayed 
 or finished with a hollow moulding, 
 or are covered by the base mould- 
 ings. 
 
 Plinth, the square footing below the 
 bases of Ionic and Corinthian co- 
 lumns. In Grecian architecture 
 plinths do not appear to have been 
 employed, the bases of the columns 
 resting upon the upper step of the 
 building. The Latin \vordplinthus 
 is derived from the Greek, signifying 
 a tile. 
 
 Plinthus, any rectangular parallelopi- 
 ped ; a brick or tile. 
 
 Pliny, whose villas were by the Ro- 
 mans objects of much attraction 
 for their design and ornament, was 
 
 341 
 
 a person of excellent judgment in 
 all the useful arts, and, living under 
 Trajan, had an opportunity of see- 
 ing the performances of and of ad- 
 vising with Apollodorus, one of the 
 greatest architects that any age pro- 
 duced : whether artists or masters 
 employed by Pliny, or Pliny him- 
 self, designed these villas, is not to 
 be determined ; but Pliny was per- 
 fectly acquainted with the whole 
 that was necessary to be under- 
 stood in their situation and dispo- 
 sition. 
 
 Plotting, among surveyors, the art 
 of describing or laying down on 
 paper, etc., the several angles and 
 lines of a tract of ground surveyed 
 by a theodolite or like instrument, 
 or a chain. 
 
 Plotting -scale, a mathematical instru- 
 ment used in plotting ground, usu- 
 ally of box-wood, sometimes of 
 brass, ivory, or silver, either a foot 
 or a foot and a half long, and about 
 an inch and a half broad. 
 
 Plug-rod the air-pump rod of a Cor- 
 nish engine. The tappets which 
 give motion to the valve are fixed 
 upon these rods. 
 
 Plumb, in ship-building, signifies to 
 be perpendicular. 
 
 Plumbago forms grey tints of greater 
 permanence and purity than most 
 blacks in general use, and it is 
 now employed for this purpose 
 with approved satisfaction by ex- 
 perienced artists. 
 
 Plumb-line, in architecture, etc., a 
 line perpendicular to the horizon, 
 made by dropping a plummet. 
 
 Plummer -block, a short carriage or 
 support for a shaft to turn in, with 
 a flat base to bolt on a frame. 
 
 Plummet, in carpentry, navigation, 
 etc., a weight of lead hung on a 
 string, by which depths are ascer- 
 tained and perpendicularity dis- 
 cerned. 
 
 Plum-tree, a handsome wood, a na- 
 tive of Europe, used principally in 
 turning, and in Tunbridge works ; 
 in the endway of the grain it re- 
 sembles cherry-tree. 
 
PLU 
 
 PNYX. 
 
 POD 
 
 Plus, in algebra, a term commonly 
 used for more, and denoted by the 
 character -f, as 6 + 10 = 16, in 
 contradistinction to , or minus, 
 less, as 16-10 = 6. 
 
 Pluteus, the wall which was some- 
 times made use of to close the 
 intervals between the columns of a 
 building, and was either of stone 
 or some material less durable. The 
 latter method was adopted only in 
 places under cover, whence that 
 kind of building was called opus 
 intestinum. The pluteus was also 
 a kind of podium, intervening be- 
 tween any two orders of columns 
 placed one above the other. The 
 word is used in this sense in the 
 description of the basilica and the 
 scene of the theatre. The pluteus 
 has been adopted between every 
 two orders of columns in the ex- 
 terior of all the theatres and am- 
 phitheatres of the Romans which 
 are known. 
 
 Pluviometer, in the arts, a rain- 
 gauge, an instrument to measure 
 the quantity of rain that falls. 
 
 Flyers, in mechanics, a kind of ba- 
 lance used in raising or letting 
 down a drawbridge. 
 
 Plying to windward, in navigation, 
 the endeavouring to make a pro- 
 gress against the wind. 
 
 Pneumatics, the properties of air or 
 fluids ; a branch of hydrostatics. 
 
 Pnyx, a name given to a place near 
 Athens, at which assemblies were 
 held for oratory, and for the dis- 
 cussion of political affairs of the 
 state ; the ancient place of the 
 Athenian parliament. According 
 to Plutarch, who has described the 
 change effected by the Thirty 
 Tyrants in the aspect of the ora- 
 tory, it was turned from the sea 
 in order to divert the assembled 
 people from being reminded by 
 their orators of maritime affairs, 
 the basis of Athenian dominion. No 
 traveller, it is said, has hitherto 
 remarked the circumstance of the 
 position of the ancient city wall, 
 by which the Pnyx was doubtless 
 
 enclosed during and after the Pelo- 
 ponnesian war. Plutarch further 
 remarks: " Themistocles did not 
 bring the Piraeus into the city, as 
 Aristophanes would have had it; 
 but he joined the city by a line of 
 communication to the Piraeus, and 
 the land to the sea." This mea- 
 sure strengthened the people 
 against the nobility, and made 
 them bolder and more intracta- 
 ble, as the power came with wealth 
 into the hands of masters of ships, 
 mariners, and pilots. Hence it 
 was that the oratory in the Pnyx, 
 which was built to front the sea, 
 was afterwards turned by the Thirty 
 Tyrants towards the land, as they 
 believed a maritime power to be 
 inclinable to a democracy, whereas 
 persons employed in agriculture 
 would be less uneasy under an oli- 
 garchy. 
 
 Podium, in Greek architecture, a 
 continued pedestal, for supporting 
 a row of columns, or serving for a 
 parapet, or forming a sort of terrace, 
 as the podium of a theatre or am- 
 phitheatre. It consists of a plinth, 
 base, die, and corona, all which 
 were continued without interrup- 
 tion around three sides of the 
 building. The podium was also 
 adopted in the scenes of theatres ; 
 and here, instead of being unin- 
 terupted, it was frequently broken 
 round the basis of the columns, 
 and formed what are commonly 
 called pedestals. Vitruvius seems 
 to consider the podium as a pede- 
 stal continued the whole length of 
 a building, and to have been so 
 called both when there were pil- 
 lars placed on it, or only supported 
 by a wall. When pillars were 
 placed on the sides of buildings, 
 sometimes, instead of having the 
 podium continued the whole length 
 in one line, it was made to break 
 forward under every pillar, which 
 part so advancing was called the 
 stylobate, and that which was be- 
 twixt the pillars under the wall, 
 was the podium. 
 
POI 
 
 POLARIZATION. 
 
 POL 
 
 Pointed or Christian Architecture 
 had its rise about the twelfth 
 century. Very many beautiful ex- 
 amples exist in England. It was 
 also employed in Germany. Mr. 
 W. Pugin says, that Pointed archi- 
 tecture does not conceal her con- 
 struction, but beautifies it. A 
 buttress in Pointed architecture at 
 once shows its purpose, and di- 
 minishes naturally as it rises, and 
 has less to resist. Here are the 
 true principles of Christian archi- 
 tecture, by the conversion of an 
 essential support of the building 
 into a light and elegant decora- 
 tion. 
 
 Point, in navigation, one of the 
 thirty-two divisions into which 
 the circumference of the horizon 
 and the mariner's compass are 
 distinguished, each comprehending 
 11 15'. 
 
 Point of horse, in mining, the spot 
 where the vein is divided into one 
 or more branches. 
 
 Polacre, in navigation, a merchant 
 vessel of the Mediterranean, having 
 three pole-masts, without tops, 
 caps, or cross-trees, with a bow- 
 sprit of one piece. 
 
 Polarization. If a round hailstone 
 drop upon the sloping roof of a 
 house, it will act, as regards its 
 rebound, just in the same manner 
 whether the slope be towards the 
 north, south, east, or west. But 
 this will not be the case with an 
 arrow under the same circum- 
 stances, because it has a distinction 
 of sides, and its behaviour will 
 vary according as the plane of its 
 barbs is parallel with the eaves or 
 with the rafters of the roof, or in- 
 clined to both. A bullet in its 
 flight from a gun has also sides to 
 its motion (though not to its form), 
 because it revolves on an axis, 
 which may be vertical, horizontal, 
 or inclined : but if shot from a 
 rifle, it has no such sides, because, 
 though spinning on an axis, that 
 axis has, by a particular contri- 
 vance, been made to coincide with 
 
 its line of motion, so that it pre- 
 sents the same aspect above, below 
 or on either side. Now if these 
 projectiles were too small or too 
 rapid for us to discover the reason 
 of these differences, we might still 
 observe the differences themselves, 
 and should express them by saying 
 that the motion of the arrow or 
 the gun-bullet possessed polarity, 
 or polarization, which was not the 
 case with that of the hailstone or 
 the rifle-bullet. Polarity, then, 
 means simply a difference of sides. 
 That a ray of light should (in 
 some cases) possess this property 
 is not perhaps so wonderful or un- 
 expected as that man should have 
 been able to detect a fact so refined 
 and remote from common observa- 
 tion, and even to distinguish dif- 
 ferent varieties of it, and investi- 
 gate its laws. Indeed, these must 
 be regarded as the very penetralia 
 of physics, the very inmost secrets 
 of Nature that man has been en- 
 abled to wrest from her. If the 
 measurable spaces occupied by the 
 waves of light be minute, how far 
 less, in all probability, must be 
 those immeasurable spaces to which 
 its vibrations are confined (which 
 even in sound are mostly inappre- 
 ciable, though the waves occupy 
 many feet) ; yet it is to the posi- 
 tions of these inconceivably mi- 
 nute vibrations that the differences 
 of polarization are due. 
 
 Poldway, coarse sacking for coal- 
 sacks, etc. 
 
 Pole-masts, in navigation, are those 
 made of single trees or spars, in 
 contradistinction to those made of 
 several pieces. 
 
 Pole-plate, a small wall-plate used in 
 roofs to receive the pitch of the 
 rafters. 
 
 Polroz, in mining, the pit underneath 
 a waterwheel. 
 
 Polychromy is the art and practice 
 of painting in positive colours, 
 either on flat surfaces or sculp- 
 tured forms, and has been referred 
 for its origin to other than aesthe- 
 
POL 
 
 PORCH. 
 
 POR 
 
 tic motives. The object of poly- 
 chromy is to heighten the effect of 
 architectural decoration, either by 
 causing a more just subordination 
 of the various parts than can be 
 obtained by mere chiaroscuro, or 
 in supplying deficiencies that could 
 not be so well filled up by any 
 other means. Professor Cockerell, 
 who travelled and learned much 
 in Greece, was the first who 
 brought it to light in this coun- 
 try. This very interesting deco- 
 rative art had its origin doubtless 
 in Egypt ; but the Greeks excelled, 
 as in all art, by the existing evi- 
 dence of the temples of their per- 
 fection of architectural art. The 
 interior decorations of Pompeii are 
 also evidences of a refinement of 
 taste, and in Gothic polychromy 
 the designers and operatives have 
 shown some talent. A free and 
 bold style in arabesque prevailed 
 from the time of Henry III. until 
 the close of the reign of Edward 
 III. Bright and lively colours 
 were applied to masses, and the 
 grounds covered with compositions 
 of foliage and birds, animals and 
 human figures ; sometimes in one 
 tint, sometimes in varied colours. 
 Many beautiful examples still <exist 
 in our cathedrals and some parish 
 churches. 
 
 Poly/oil, an ornament formed by a 
 moulding disposed in a number of 
 segments of circles. 
 
 Poll/style, having a number of co- 
 lumns. Where columns occur be- 
 hind columns, as where a portico 
 has inner columns, like that of the 
 Royal Exchange, such portico may 
 be termed polystyle. 
 
 Pomel, a boss or knob used as an or- 
 namental top of a conical or dome- 
 shaped roof of a turret, etc. A 
 large copper ball or pomel is on 
 the summit of a timber spire of 
 Lincoln cathedral. 
 
 Pons (Latin), a bridge. The most 
 ancient bridge upon record is the 
 one erected by Nitocris over the 
 Euphrates at Babylon. 
 
 Poon wood, of Singapore, is of a light 
 porous texture, and light greyish 
 cedar colour; it is used in ship- 
 building for planks, and makes ex- 
 cellent spars. The Calcutta poon 
 is preferred. 
 
 Poplar wood. There are five species 
 common to England, of which the 
 abele, or great white poplar, and the 
 Lombardy poplar, are most used. 
 The woods are soft, light, easy to 
 work, suited for carving, common 
 turnery, etc. 
 
 Poppets, perpendicular pieces that are 
 fixed on the fore and aftermost 
 parts of the bulgeways, to support 
 the ship while being launched. 
 
 Poppet-head, that part of a lathe 
 which holds the back centre, and 
 can be fixed on any part of the 
 bed. 
 
 Poppy, an ornament representing the 
 poppy-head, used on the tops of 
 the upright ends or elbows which 
 terminate scats, etc., in churches. 
 
 Poppy-head, in architecture, a carved 
 ornament at the apex of a standard 
 or open seats in Gothic churches, 
 also carved into an ornamental 
 finial, pomel, or crest, etc. 
 
 Porcelain clay, in mineralogy, a sub- 
 stance of great infusibility, derived 
 from disintegrated felspar. 
 
 Porch, in architecture, a roof sup- 
 ported on pillars before a door ; a 
 kind of vestibule supported by pil- 
 lars. Any small portico consider- 
 ably lower than the main structure 
 to which it is attached may be so 
 termed, in contradistinction from 
 one carried up the height of the 
 building, or as high as the principal 
 cornice. Porches were used in Nor- 
 man architecture, in Early English, 
 and commonly in subsequent dates. 
 When the fashion of building houses 
 on quadrangular plans was discon- 
 tinued, a porch of at least two 
 stories, and sometimes the whole 
 height of the building, succeeded 
 the gate-house. Low porches had 
 been used as entrances from inner 
 courts from an early date ; and of 
 the time of Henry VIII. one may 
 
FOR 
 
 PORTS. 
 
 FOR 
 
 be mentioned at Cowdry, attached 
 to the door leading from the court 
 to the hall. 
 
 Pores, small interstices between the 
 solid particles of bodies. 
 
 Porisms, in geometry, a name applied 
 by the ancients to certain compre- 
 hensive and indefinite problems. 
 
 Port, in navigation, the larboard or 
 left side of a ship ; as ' a-keel to 
 port ' is an inclination to the lar- 
 board side. 
 
 Ports, the holes in the ship to run 
 the guns out. 
 
 Port-lids, shutters to the ports. 
 
 Ports and buildings constructed in 
 water. Vitruvius writes: "The op- 
 portunity which presents itself of 
 giving some account of ports, and 
 by what means protection may be 
 afforded to ships from the elements, 
 ought not to be neglected. The 
 positions best adapted by nature to 
 such a purpose are bays with capes 
 and promontories at their extremi- 
 ties, from which the shore recedes 
 inwardly in a curved line. Upon 
 shores of this description, docks 
 may be built or porticoes erected, 
 or a channel cut from the port to 
 the emporium, defended by towers 
 on each side, in which machines 
 may be constructed for throwing 
 booms across the passage. If, how- 
 ever, no situation can be found 
 capable by its formation of protec- 
 ing vessels against the violence of 
 the sea, we must search for a snot 
 where a promontory presents itself 
 on one side, and where no river 
 discharges itself so as to oppose its 
 application to the purposes of a 
 harbour, and supply the want of a 
 corresponding projection on the 
 other by building walls and but- 
 tresses. The walls, which it be- 
 comes necessary in this case to 
 construct in the water, may be 
 thus formed : sand should first be 
 procured from that part of the 
 coast lying between Carnac and 
 the promontory of Minerva, and 
 mixed with lime in the proportion 
 of two parts to one ; then rows of 
 
 grooved beams must be driven in 
 the water, connected by oaken 
 planks, and bound together by 
 chains. The surface of the ground 
 below the water, on which the 
 wall is to be raised, must then be 
 madeeven bymeansof transtilli,and 
 the space comprehended between 
 the beams filled with a composi- 
 tion consisting of rough stone and 
 cement, made in the manner just 
 described. Such is the quality of 
 the sand produced in these spots, 
 that the composition becomes a 
 solid wall." 
 
 Port the helm. In navigation this 
 phrase directs a ship's course fur- 
 ther to the right, or starboard, by 
 putting the helm to larboard. 
 
 Porta (Latin), the gate of a city, cita- 
 del, or other open space, enclosed 
 by a wall, in contradistinction to 
 janua, which was the door or en- 
 trance to any covered building. 
 
 Portal, the arch over a door or gate- 
 way ; an entrance under cover. 
 
 Portcullis, a strong defensive frame- 
 work of timber, hung in grooves 
 within the chief gateway of a for- 
 tress, or a castle, or an edifice of 
 safety : it resembles the harrow, but 
 is placed vertically, having a row of 
 iron spikes at the bottom, and is 
 let down to stop the passage in case 
 of assault. 
 
 Portico, in architecture, a covered 
 walk supported by columns, and 
 usually vaulted ; a piazza or arched 
 pathway. (For the different plans 
 and denominations of porticoes, 
 see ' Rudimentary Architecture,' 
 Part I.) 
 
 Porticus (Latin), a walk covered with 
 a roof which is supported by 
 columns. A portico was either 
 attached to temples and public 
 buildings, or it was built indepen- 
 dent of any other edifice. 
 
 Porticus (deinde). In the houses of 
 the Roman citizens, between the 
 atrium (hall, or servants' room) and 
 the inner court, there was usually 
 a room called the tablinum (corri- 
 dor), mentioned by Vitruvius. This 
 
FOR 
 
 PORTICUS. 
 
 POW 
 
 porticus lay betwixt the atnum 
 and the cavaedium. The reason 
 for his giving it this round form 
 may be upon two accounts : first, 
 to give a greater grace to its pro- 
 jection, and to make the forepart 
 of it serve for a more beautiful 
 vestibulum to the house; and in 
 the next place, as being designed for 
 a shelter in tempestuous weather, 
 it the better broke the force of 
 those winds that blew on that side 
 than if it had been more square. 
 
 Porticus. By the Romans this was 
 a common name given to all build- 
 ings that had walks under the 
 cover of a roof or ceiling, sup- 
 ported by pillars or pilasters, 
 though differently called, according 
 to the disposition of the pillars : 
 when placed on the outside of a 
 building, as round some of their 
 temples, it was called peripterium ; 
 when these ranges of pillars were 
 within a room, as they were some- 
 times in their triclinia, lasilicce, 
 atria, and temples, the void space 
 betwixt the pillars and the side 
 walls was called aloe; but when 
 pillars surrounded courts, and had 
 walks betwixt them and'the walls, 
 these ranges of pillars were called 
 peristylia, and the walk betwixt 
 was called a. porticus. 
 
 Portland stone, an alkaline sandstone, 
 of a dull whitish colour, heavy and 
 moderately hard, and somewhat flat 
 texture, and composed of large 
 rounded grit, cemented together 
 by an earthy spar, and intermixed 
 with numerous glittering spangles 
 of pure spar : the grit splits in the 
 cutting of the stone, so that it is 
 capable of being brought to a sur- 
 face very smooth and equal : it will 
 not strike fire with a steel, and 
 burns to a slight ashen hue. It 
 has been and is much used for all 
 kinds of buildings, particularly in 
 the lars;e structures in London: it is 
 brought from the island of Portland, 
 in Dorsetshire. 
 
 Post, an upright timber in a building ; 
 those used in modern roofs are 
 
 called king-posts or queen-posts, 
 according to their number and po- 
 sition. 
 
 Post Meridiem (P.M.], after mid-day. 
 
 Postern, a small doorway or gateway 
 at the back of a building ; a small 
 doorway for private communica- 
 tion with the exterior of a castle 
 or fortress. 
 
 Postigue, in architecture, an orna- 
 ment of sculpture superadded when 
 the original plan has been com- 
 pleted. 
 
 Pot-metal, a species of stained glass, 
 the colours of which are incorpo- 
 rated within the glass while in a 
 state of fusion. 
 
 Poudrette, a French word, signify- 
 ing powdered dung ; but the word 
 is applied, when treating of human 
 excrement, in its meaning to the 
 solid of that soil after the liquid 
 manure has discharged itself. In 
 a vine-growing district near Paris 
 (see article Fosses d'aisances) pou- 
 drette was used for manure, and, 
 although the application of it pro- 
 duced a great abundance of fruit, 
 yet the wine proved very inferior 
 to that which had been previously 
 made on the same ground. 
 
 Power, in mechanics : this denotes a 
 force which, being applied to a 
 machine, tends to produce motion 
 or pressure. 
 
 Power, horse, in mechanics, an ex- 
 pression used to denote the power 
 of a steam-engine, that is to say, 
 how many horses' work it will save. 
 If a horse standing still can by his 
 strength keep a weight of 169 Ibs. 
 from falling, when suspended over 
 a pulley, he will exert 121 Ibs. at 
 two miles per hour; 100 Ibs. at 
 three; 8 libs, at four; 64 Ibs. at 
 five ; 49 Ibs. at six ; 361bs. at seven ; 
 25 Ibs. at eight; 16 Ibs. at nine; 
 9 Ibs. at ten ; 4 Ibs. at eleven ; and 
 lib. at twelve miles per hour. 
 
 Power-loom, in mechanics, a loom 
 moved by the mechanical force of 
 steam, wind, water, etc., as con- 
 tradistinguished from handweav- 
 ing. 
 
OY 
 
 PRISM. 
 
 PRO 
 
 'oyntell, paving formed into small 
 lozenges or squares laid diagonally. 
 'rcecinctiones, the passages or corri- 
 dors which separated the several 
 ranges of seats in an ancient Ro- 
 man theatre. 
 
 *ressure of fluids consists of two kinds, 
 elastic and non-elastic. The first 
 is comprehended in the science of 
 pneumatics, the second in that of 
 hydrostatics. Both classes of fluids 
 deviate from solid substances in 
 their greater distribution of any 
 pressure to which they may be 
 subjected. Thus solid bodies press 
 downwards only by the force of 
 gravity ; all fluids, on the contrary, 
 press not only in this direction, 
 but upwards, sideways, and every 
 way equally. The incompressi- 
 bility of water renders it service- 
 able by this principle, in the hy- 
 drostatic press. 
 
 ^reventer bolts, those which are 
 driven at the lower end of the pre- 
 venter plates, to assist the strain 
 of the chain-bolts. 
 reventer plates, in ships, plates of 
 iron below the links of the chains. 
 J 'richer, a thin piece of iron, used to 
 make a hole for the fusee or match 
 to fire a blast. 
 
 ill, a solid piece of ore, a speci- 
 men. 
 
 Criming, the effect engendered by 
 having too little steam room in the 
 boiler of a steam-engine. Minute 
 particles of water being carried into 
 the cylinder, collect in a body, 
 which obstructs the passage of the 
 piston, and causes a considerable 
 loss of power. 
 
 Crime's metal, in metallurgy, an alloy 
 of copper, in imitation of silver, in 
 which the proportion of zinc is 
 greater than in brass. 
 incipal brace, a brace immediately 
 under the principal rafters or pa- 
 rallel to them, in a state of com- 
 pression, assisting with the princi- 
 pals to support the timbers of a 
 roof : they are employed in the 
 present roof of St. Paul's church, 
 Covent Garden. 
 
 Priory, a monastic establishment for 
 the devotional requirements and 
 maintenance of a religious frater- 
 nity, under the government of a 
 prior. Many priories were for- 
 merly scattered over Britain. 
 Prism, in geometry, a body or solid 
 whose two-thirds are any plane 
 figures which are parallel, equal, 
 and similar, and its sides paral- 
 lelograms. 
 
 Prism, in optics, a triangular bar of 
 glass, well known from the effect it 
 produces on a ray of light trans- 
 mitted through it : this effect is a 
 decomposition of the light into its 
 component emanations, consisting 
 of the three primary colours and 
 the secondary tints arising from 
 their intermixture, which together 
 form what is termed the solar 
 spectrum. The lensic prism is a 
 new optical glass, in which the 
 powers of the lens and prism are 
 combined. 
 
 Prison, an edifice, unfortunately 
 mostly of large dimensions, for 
 the confinement of persons warring 
 against society. 
 
 Profile, the outline of a series of 
 mouldings, or of any other parts, as 
 shown by a section through them. 
 Profile of an Order, in architecture, 
 an assemblage and arrangement of 
 essential and subservient parts. 
 That profile is preferable wherein 
 the parts are few, varied, and fitly 
 applied. Some member should pre- 
 dominate in each division, which it 
 should appear the office of the other 
 parts to fortify, support, or shelter. 
 In a cornice the corona is sup- 
 ported by modillions, dentils, ovo- 
 los, etc., and sheltered and covered 
 from the effects of the weather by 
 its cyma or cavetto. 
 Projectile, in mechanics, a body put 
 
 in motion by an external force. 
 Projectiles, in mechanics, that branch 
 which considers the mass, velocity, 
 range, etc., of a heavy body pro- 
 jected into void space by an exter- 
 nal force, and then left to the free 
 action of gravity. 
 
PRO 
 
 PROPORTION. 
 
 PRO 
 
 Projection, in geometry, drawing, itc., 
 a plan or delineation ; in chemistry, 
 the crisis of an operation. 
 
 Prqjecture, in architecture, the out- 
 jutting or prominence which the 
 moulding and members have be- 
 yond the plane of a wall or column. 
 
 Prolate, in geometry, an epithet ap- 
 plied to a spheroid produced by the 
 revolution of a semi-ellipsis about 
 its long diameter. 
 
 Pronaos, the area immediately before 
 a temple. The term is often used 
 for the portico in front of a build- 
 ing. The porticus in one front 
 corresponds to the pronaos in the 
 other : in some temples, the cella 
 was entered through both. The 
 generality of Grecian temples had 
 two approaches. 
 
 Proportion, in architecture, the mag- 
 nitude of one part as compared 
 with some other. The term ' pro- 
 portion' is used absolutely in the 
 sense of * good proportion ,' although 
 everything that has shape has pro- 
 portions of some kind or other. 
 The subject of proportion has been 
 greatly mystified by writers, who 
 have laid down certain fixed pro- 
 portions as the best of all on every 
 occasion, and as the ne plus ultra 
 of artistic taste. But fixed propor- 
 tions can be followed mechanically 
 by every one alike ; whereas it re- 
 quires ability to deviate successfully 
 from routine measurement, and ap- 
 ply the poco piu or the poco meno 
 as the particular occasion or the 
 particular effect aimed at may re- 
 quire at least, justify. It is the 
 eye that takes cognizance of pro- 
 portions ; and the architect's own 
 eye ought to be quite as correct as 
 that of other people. 
 
 Proportion, that branch of mathe- 
 matical science which defines the 
 ratio of numbers or quantities to 
 each other. 
 
 Proportions of rooms should be suited 
 to the purposes for which they are 
 used ; all figures, from the square 
 to one and a half the breadth of 
 the room, may be employed for the 
 
 plan. Some have extended the 
 plan to a double square. Galleries 
 may be from five to eight times 
 their breadth. The height, if with 
 flat ceilings, is not required to be so 
 great as in those that are covered. 
 The height of square apartments 
 should not exceed five-sixths the 
 side of the square, nor be less than 
 four-fifths ; but in rooms that are 
 oblong, the height ought to be 
 equal to the breadth. The height 
 of square rooms that are covered 
 should be equal to one of the sides 
 of the square ; but covered oblong 
 rooms require a height equal to the 
 breadth, added to one-fifth, one- 
 quarter, or, at most, one-third of 
 the difference between their length 
 and breadth. The height of gal- 
 leries should be from one and three 
 fifths at most, to one and one-thirc 
 at least, of their breadth. Cornicei 
 and dressings in the interior o 
 houses are always to be kept more 
 delicate than those on the out- 
 side. 
 
 Propyl&um, in Greek architecture, 
 the porch of a temple or great hall. 
 
 Propylaa : the entrance to a Greek 
 temple, a sacred enclosure, con- 
 sisted of a gateway flanked by 
 buildings, whence the plural of the 
 word. The Egyptian temples gene 
 rally had magnificent propylaea,con 
 sisting of a pair of oblong truncatet 
 pyramids of solid masonry, the face 
 of which were sculptured with hie' 
 roglyphics. The word, however 
 is generally used to signify the en- 
 trance to the Acropolis of Athens, 
 which was the last completed of 
 the great works of architecture 
 executed under the administratioB 
 of Pericles. Pausanias relates that 
 " there is only one entrance to the 
 acropolis, it being in every re- 
 maining part of its circuit a preci- 
 pice, and fortified with strong walls. 
 This entrance was fronted by a 
 magnificent building, called the 
 propylaea, covered with roofs ol 
 white marble, which surpassed foi 
 beauty, and the dimensions of the 
 
PRUSSIAN BLUE. 
 
 PRTJ 
 
 marble, all that he had before seen." 
 The binding was commenced during 
 the administration of Pericles, and 
 finished in five years, Mnesicles 
 being the architect, at the expense 
 of 2,012 talents, or nearly464,000 
 sterling. There were five gates to 
 the propylaea, and before it stood 
 two lofty piers, on each of which 
 was placed an equestrian statue, 
 supposed to be the sons of Xeno- 
 phon. On the right of the pro- 
 pyljea was the temple of Victory 
 without wings, whence is a pro- 
 spect of the sea ; and from this place 
 it was said that /Egeus threw him- 
 self down headlong, and died. On 
 the left of the propylaea was* an 
 edifice adorned with paintings, the 
 work of Polygnotus, of which, says 
 Pausanias, though some were ef- 
 faced by time, there still remained 
 those of Diomedes and Ulysses, 
 the one bearing off the bow and 
 arrows of Philoctetes from Lemnos, 
 the other, the Palladium from Troy. 
 There were those also of Orestes 
 slaying .Egisthus, and Pylades en- 
 countering the sons of Xauplius, 
 who had come to succour JSgis- 
 thus ; Polynexa, at the sepulchre 
 of Achilles, about to be sacri- 
 ficed, and Ulysses addressing him- 
 self to Nausicaa and her maidens, as 
 described by Homer. Several other 
 pictures in the same place are 
 described by Pausanias. Thee 
 three contiguous buildings origi- 
 nally formed one front, occupying 
 the whole breadth of the rock from 
 side to side, at its western epd, 
 so that tbe only admission into the 
 acropolis was through the middle 
 building, the five gates of which 
 are still remaining, and prove it to 
 have been the propylaea. It may be 
 supposed that the Hermes Propy- 
 lasus was here placed, and perhaps 
 the Graces, a piece of Sculpture by 
 the hand of Socrates, in which that 
 celebrated philosopher, deviating 
 from the practice of the sculptors 
 who preceded him, had repre- 
 sented them not naked but clothed. 
 
 Other sculptors are also men- 
 tioned by Pausanias who seem to 
 have decorated this stately en- 
 trance. 
 
 Proscenium, the area in front of the 
 scene of a theatre, which was per- 
 ceived when the pulpitum was re- 
 moved, and when it is probable the 
 temporary scenes were taken away 
 in order to exhibit the front of the 
 permanent scene. 
 
 Prostyle, a temple which has a por- 
 tico in one front, consisting of in- 
 sulated columns with their entabla- 
 tures and fastigium. When the 
 temple had a portico in both fronts, 
 it was termed am phi-prostyle, or 
 prostyle in all parts. 
 
 Protractor, in surveying and trigo- 
 nometry, an instrument by which 
 angles taken in the field with a 
 theodolite-circumferentor are re- 
 presented on paper. 
 
 Prow, in navigation, the head or fore- 
 part of a ship, in opposition to the 
 poop or stern. 
 
 Pruxssian Blue, otherwise called Ber- 
 lin blue, Parisian blue, Prussiate of 
 iron, cyanide of iron, or, in lan- 
 guage more pedantically chemical, 
 per-ferro-cyanate of iron, with 
 alumine, etc., is rather a modern 
 pigment, produced by the com- 
 bination of the prussic or hydro- 
 cyanic acid, iron, and alumina. It 
 is of a deep and powerful blue 
 colour, of vast body and consider- 
 able transparency, and forms tints 
 of much beauty with white-lead, 
 though they are by no means equal 
 in purity and brilliancy to those 
 of cobalt or ultramarine, nor have 
 they the perfect durability of the 
 latter. 
 
 Pruxsian Brown is a preparation of 
 Prussian blue from which the blue 
 colouring principle has been ex- 
 pelled by fire, or extracted by an 
 alkaline ley : it is an orange-brown, 
 of the nature and properties of 
 Siena earth, and dries well in oil. 
 
 Prussian Green. The pigment cele- 
 brated under this name is an im- 
 perfect prussiate of iron, or Prus- 
 
 349 
 
PRU 
 
 PUMP. 
 
 PUM 
 
 sian blue, in which the yetlow 
 oxide of iron superabounds, or to 
 which yellow tincture of French 
 berries has been added, but is not 
 in any respect superior as a pig- 
 ment to the compounds of Prussian 
 blue and yellow ochre. A better 
 sort of Prussian green is formed 
 by precipitating the priresiate of 
 potash with nitrate of cobalt. 
 
 Prussiate of Copper differs chemically 
 from Prussian blue only in having 
 copper instead of iron for its basis. 
 It varies in colour from russet to 
 brown, is transparent and deep, 
 but being very liable to change in 
 colour by the action of light or by 
 other pigments, it has been very 
 little employed by artists. 
 
 Pryan, in mining, that which is pro- 
 ductive of ore, but does not break 
 in large stones, but only in pebbles 
 with a mixture of clay. 
 
 Pseudo-dipteral, a temple which has 
 a single range of columns in the 
 flanks, at the same distance from 
 the walls of the cella as though 
 the temple had been dipteral. 
 
 Pteroma, the spaces between the 
 walls of the cella of a temple and 
 the columns of a peristyle ; called 
 also amlulatio. 
 
 Puddling, in metallurgy, a process in 
 the refining of iron which consists 
 in stirring it actively about. 
 
 Pulley, one of the six mechanical 
 powers. The pulley is a small 
 wheel turning on an axis, with a 
 rope or chain passing over it. The 
 circumference is generally grooved 
 to receive the rope, which is at- 
 tached on the one end to the mov- 
 ing power, and on the other to the 
 resisting force. Pulleys are of two 
 kinds fixed and movable. The 
 fixed pulley gives no mechanical 
 advantage, but is of great utility in 
 altering the direction in which it 
 may be applied. The movable, on 
 the contrary, doubles the power, 
 which may be increased in any 
 ratio by adding to the number of 
 pulleys. In a combination of 
 pulleys, the advantage, however, 
 
 is greatly diminished by the fric- 
 tion of the axles and of the ropes. 
 Too complex a combination there- 
 fore would not be of service, as the 
 friction would be increased without 
 a proportional advantage, and from 
 the complexity of the machine 
 would be more liable to be put out 
 of order. 
 
 Pulpit, an elevated stage or desk 
 from which sermons are delivered. 
 
 Pulpitum, the wooden stage of the 
 theatre upon which the mimic as 
 well as dramatic exhibitions of the 
 Romans were represented. In the 
 Greek theatre, the pulpitum was 
 used only by the histriones, or 
 performers in the drama, and 
 was probably removed before the 
 amusements of the orchestra were 
 exhibited. . \ 
 
 Pulvinated. A frieze whose face is 
 convex instead of plain is said to 
 be pulvinated, from its supposed 
 resemblance to the side of a 
 cushion, which swells out when 
 pressed upon. 
 
 Pump, an engine for raising liquids, 
 made in various forms, of more or 
 less complexity of parts and effec- 
 tiveness of action, depending in its 
 simplest form upon the external 
 pressure of the air on the surface of 
 the water, and in other forms deriv- 
 ing its power from the abstraction 
 of the air within the tube or barrel. 
 The simplest form of pump is that 
 of the common lift-pump, which 
 consists of a straight tube with two 
 valves, one of which is fitted to the 
 lower end. of the tube, and the other 
 is made to slide air-tight in the 
 cavity of the tube or barrel. Both 
 of these valves are adapted to open 
 upwards only, and thus the water 
 is admitted and lifted from the 
 lower part of the tube to the dis- 
 charge aperture above. This pump 
 acts by the pressure of the atmo- 
 sphere upon the external body of 
 water from which the supply is 
 raised, but by the forcing-pump 
 water may be raised above the level 
 to which it is driven by the pressure 
 
PUM 
 
 PUMP. 
 
 PUM 
 
 of the atmosphere. The forcing- 
 pump consists of a barrel fitted 
 with a solid piston or forcer, the 
 barrel being also provided with a 
 branch forcing-pipe. The lower 
 part of the barrel and the branch- 
 pipe are each fitted with a valve 
 opening upwards, and by repeated 
 strokes of the piston, the pressure 
 of the air from above being removed, 
 the fluid is brought up to fill the 
 space between the two valves, and 
 being prevented from returning by 
 the lower valve, it passes through 
 the upper valve of the branch-pipe 
 into a capacious upper vessel, and 
 there accumulating, may be ejected 
 in a constant instead of intermittent 
 stream. The lift-pump, being simple 
 and economical in construction, is 
 well fitted for extensive works in 
 which the quantity of water to be 
 raised is considerable, and is there- 
 fore usually employed in works for 
 supplying water for towns. The 
 pumps used at the Metropolitan 
 and other waterworks are of great 
 size, and deliver immense volumes 
 of water at each stroke. Those 
 used at Haarlem are 63 inches in 
 diameter, and the pistons have a 
 stroke of 10 feet in length. Each 
 pump delivers 6 tons of water at 
 each stroke. Pumps of this magni- 
 tude are worked by water or steam 
 power. Those at Haarlem, eleven 
 in number, are worked simultane- 
 ously by a steam-engine, having 
 two steam-cylinders, one within the 
 other, the larger being 12 and the 
 smaller 7 feet in diameter, with a 
 stroke of 10 ft. (See For tiny Pump.} 
 Mr. Appold's centrifugal 
 pump for draining marshes, and 
 for other purposes, will discharge 
 10 gallons of water per minute, 
 and is only 1 inch diameter : one 
 of the same shape, 12 inches dia- 
 meter, will discharge at the same 
 speed of the outside circumference, 
 or Y 1 ^ the number of revolutions, 
 1,440 gallons per minute, being ac- 
 cording to the square of the dia- 
 meter, and not according to the 
 
 cubic contents. From various ex- 
 periments, it has been found that 
 the larger model with the curved 
 vanes does the most duty, on ac- 
 count of its receiving and delivering 
 the water more obliquely : it will 
 discharge 1,800 gallons per minute, 
 with 607 revolutions, but does the 
 most duty at 535 revolutions, dis- 
 charging 1,400 gallons; therefore, 
 if a pump 1 inch diameter raise 10 
 gallons, and another 1 foot dia- 
 meter 1,440 gallons, it follows that 
 one 
 
 gals, permin. 
 10 feet diameter, of the 
 
 best shape,will pump 140,000 
 20 ditto, ditto . . . 560,000 
 40 ditto, ditto . . . 2,240,000 
 
 To do the above duty, the cir- 
 cumference of the 20-feet pump 
 would be required to travel 560 
 yards per minute, which would be 
 only 53^ revolutions, and the 40- 
 feet 26|. 
 
 From the results of various ex- 
 periments, it has been found that 
 the loss of power would not be 
 more than 25 per cent. It will be 
 observed, the centrifugal force is 
 not so much in the large diameter, 
 on account of the water moving 
 more in a straight line ; but that is 
 compensated for by the force being 
 applied to a greater depth of water, 
 being 10 feet in the 40-feet, and 
 only 3 inches in the 1-foot. 
 
 ft. high. 
 
 159 revolutions, with the 1- 
 foot, will raise the water, 
 without discharging any, 1 
 
 318 revolutions 4 
 
 636 ditto 16 
 
 1272 ditto 64 
 
 The highest elevation to which 
 the water has been raised with the 
 1-foot pump, is 67 feet 8 inches, 
 with 1,322 revolutions per minute, 
 being less than the calculated 
 height, which may be accounted 
 for by leakage with the extra 
 strain. 
 
 While the 1-foot pump is raising 
 
PUM 
 
 PUNCH. 
 
 PUN 
 
 J. UJXft 1 Ui.lV/Al. 
 
 8 tons of water 5 feet 6 inches hi&h 
 
 Dimensions of the Pump. 
 
 
 per minute, there is no greater 
 
 Diameter 1 foot 
 
 
 strain on any part of the pump 
 
 Width 3 innbfis. 
 
 than 160 Ibs. on the 6-inch drum, 
 which is equal to a leverage of 3 
 
 Conten 
 
 ts 
 
 . 1 gallon. 
 
 
 inches. (See the results of various 
 
 ^^~^~~-\ 
 
 
 experiments in the following 
 
 /^/ ^\ 
 
 
 Table.) It will pass almost any- 
 
 A / x^'^r^^x & \ 
 
 I 
 
 thing that is small enough to go 
 
 (\ \/ ^ > \\ \ ^ 
 
 
 
 through, there being no valves. 
 
 [ \ i \ \ 1 
 
 
 A quantity of nut-galls (about a 
 
 \ NA A \ 1 
 
 
 gallon) were thrown into the 1-foot 
 
 V ^\ Sv ____yy 1 1 *\ / 
 
 - 
 
 pump all at once, when it was at 
 
 ^^-^'^ / Jf * 
 
 
 full speed, and they passed through 
 
 N^^ .// 
 
 
 without breaking one. 
 
 
 
 Table of Mean Results of various Experiments with Mr. Appold's 
 
 
 Centrifugal Pump. 
 
 
 
 
 
 Strain in Ibs., 
 
 
 Percentage 
 of work done 
 compared 
 with power 
 expended. 
 
 No. of 
 revolutions 
 per minute 
 of 6- inch 
 drum and 
 pump. 
 
 Number of 
 gallons raised 
 5 feet 6 inches 
 high per 
 minute. 
 
 Equivalent in 
 Ibs. raised 1 foot 
 high per minute. 
 
 on a drum of 
 4 ft. diameter 
 driving one of 
 6 in. diameter, 
 as measured 
 by a 
 
 Equivalent 
 strain on the 
 steam-engine, 
 rated in Ibs. 
 raised 1 foot high 
 per minute. 
 
 
 
 
 dynamometer. 
 
 
 400 
 
 500 
 
 27,ftOO 
 
 74 
 
 44,400 
 
 61-7 
 
 
 412 
 
 600 
 
 33,000 
 
 80 
 
 49,440 
 
 66-7 
 
 
 427 
 
 700 
 
 38,500 
 
 87 
 
 05,723 
 
 69- 
 
 
 440 
 
 800 
 
 44,000 
 
 94 
 
 62,010 
 
 70-9 
 
 
 453 
 
 900 
 
 49,500 
 
 100 
 
 67,950 
 
 72-8 
 
 
 474 
 
 1000 
 
 55,000 
 
 106 
 
 75,366 
 
 729 
 
 
 481 
 
 1100 
 
 60,500 
 
 113 
 
 81,479 
 
 74-2 
 
 
 495 
 
 1200 
 
 66,000 
 
 118 
 
 87,615 
 
 75-3 
 
 
 518 
 
 1300 
 
 71,500 
 
 121 
 
 94,017 
 
 76- 
 
 
 535 
 
 1400 
 
 77,000 
 
 126 
 
 101,115 
 
 76-1 
 
 
 563 
 
 1500 
 
 82,500 
 
 134 
 
 113,163 
 
 72-9 
 
 
 580 
 
 1600 
 
 88,000 
 
 138 
 
 120,060 
 
 73-3 
 
 
 595 
 
 1700 
 
 93,500 
 
 142 
 
 126,733 
 
 73-6 
 
 
 607 
 
 1800 
 
 99,000 
 
 150 
 
 136,575 
 
 72-5 
 
 
 Pump, marine, a machine to draw 
 
 from the pump-cisterns through 
 
 water out of a ship's hold. 
 
 the ship's sides. 
 
 
 Pump-chain. This consists of a long 
 
 Pumping -engine, a steam-engine for 
 
 chain with valves at proper dis- 
 
 raising water. 
 
 
 tances, working on two wheels, one 
 
 Punch, in mining, a piece of timber, 
 
 above and one below, and passing 
 
 used as a support for a roof. 
 
 
 down through one wooden tube and 
 returning upwards by another. 
 
 Punch, a tool for making an impres- 
 sion, or for forcing a hole through 
 
 Pump-cistern, to receive the water 
 
 a plate. 
 
 
 from the pumps. 
 
 Puncheon, a measure of liquids con- 
 
 Pump-dales, pipes to convey water 
 
 taining eighty-four gallons. 
 
 
PUN 
 
 PUNCHING-MACHINE. 
 
 PUR 
 
 Puncheons, small upright timbers in 
 wooden partitions, now usually 
 called studs or quarters ; they are 
 placed upright between two posts 
 whose bearing is too great, serving, 
 together with them, to sustain some 
 large weight. 
 
 Punching and Plate-cutting Machine. 
 The operation of punching holes 
 through thick metal plates requires 
 machinery of a very massive de- 
 scription, on account oT the violent 
 strains to which it is subjected ; 
 and the power of these machines 
 being exerted only at intervals, it 
 is necessary to apply some means of 
 rendering the motion tolerably uni- 
 form, and thereby diminishing as 
 much as possible the violence of 
 the strain. This is effected by 
 setting in motion a heavy fly-wheel, 
 so that the power expended in 
 giving a certain velocity to the 
 wheel shall be stored up till the 
 operation of punching commences, 
 which tends to retard the motion : 
 the accumulated power in the 
 wheel will then tend to maintain 
 the speed, and thus an approxima- 
 tion to uniform motion is obtained. 
 The machine consists of a strong 
 frame, at the front of which is a 
 broad slide, moved vertically up 
 and down by an eccentric fixed on 
 the end of a shaft passing length- 
 wise through the frame : on this 
 shaft there is a large wheel, which 
 receives motion from a pinion on 
 another shaft carrying the fly- 
 wheel and driving-pulleys. The 
 punches, the number of which 
 varies according to the size of the 
 holes, are fixed in the lower end of 
 the vertical sliding-piece, and im- 
 mediately under them is fixed a 
 piece of steel, called the dies, 
 which has holes in it to correspond 
 with the punches. The plate in 
 which holes are to be punched is 
 fastened upon a travelling table in 
 front of the machine ; and the slide 
 being up, and the surface of the 
 table level with that of the dies, 
 the part where the holes are to be 
 
 punched is placed between the 
 punches and the dies, so that when 
 the machine is set in motion, the 
 punches are forced through the 
 plate by the action of the eccentric, 
 and the pieces driven out fall 
 through the holes in the dies: 
 after the punches have risen above 
 the surface of the plate, the tra- 
 velling table is set forward to the 
 required distance by self-acting 
 apparatus, and the operation is re- 
 peated by the machine till the re- 
 quired number of holes has been 
 punched. 
 
 The plate-cutting apparatus con- 
 sists of two steel-plates, forming a 
 pair of shears : the lower plate is 
 fixed on the frame of the machine, 
 and the upper one is attached to a 
 slide, as in the case of the punches, 
 acting in a similar manner. The 
 shears are moved by the same 
 shaft as the punches, and act while 
 the punches are being raised : 
 sometimes they are placed at the 
 top of the punching-slide. 
 
 Punt, in navigation, a sort of oblong, 
 flat-bottomed, small boat, with a 
 square head and stern. 
 
 Purbeck-stone, an alkaline sandstone, 
 harsh arid rough, of a disagreeable 
 ash colour, very heavy, and mo- 
 derately hard ; of a texture not 
 very compact, but somewhat po- 
 rous, and composed of an angular 
 grit, cemented together by an 
 earthy spar. It cuts freely, and 
 with a tolerably even or smooth 
 surface, but will not take a po- 
 lish : it is used principally in Lon- 
 don. The quarries are in the island 
 of Purbeck, Dorsetshire. 
 
 Purlins, in carpentry, those pieces of 
 timber that lie across the rafters 
 on the inside, to keep them from 
 sinking in the middle. 
 
 Purple, the third and last of the 
 secondary colours, is composed of 
 red and blue, in the proportions of 
 five of the former to eight of the 
 latter, which constitutes a perfect 
 purple, or one of such a hue as will 
 neutralize and best contrast a per- 
 
PUR 
 
 PURPLE. 
 
 PUZ 
 
 feet yellow in the proportion ef 
 thirteen to three of surface or in- 
 tensity. It forms, when mixed 
 with its co-secondary colour, green, 
 the tertiary colour olive, and when 
 mixed with the remaining second- 
 ary orange, it constitutes the ter- 
 tiary colour russet. 
 
 Purple Black is a preparation of 
 madder, of a deep purple hue, ap- 
 proaching to black ; its tints, with 
 white-lead, are of a purple colour. 
 It is very transparent and power- 
 ful, glazes and dries well in oil, and 
 is a durable and eligible pigment, 
 belonging perhaps to the semi-neu- 
 tral class of marrone. 
 
 Purple Lake. The best purple lake, 
 so called, is prepared from cochi- 
 neal, and is of a rich and powerful 
 colour, inclined to crimson. Its 
 character as a pigment is that of a 
 cochineal lake, already described. 
 It is fugitive both in glazing and 
 tint, but used in considerable body, 
 as in the shadows of draperies, etc., 
 it will last under favourable cir- 
 cumstances a long time. Lac lake 
 resembles it in colour, and may 
 supply its place more durably, al- 
 though not perfectly so. 
 
 Purple Ochre, or Mineral Purple, is a 
 dark ochre, a native of the forest of 
 Dean, in Gloucestershire. It is of 
 a murrey or chocolate colour, and 
 forms cool tints of a purple hue, 
 with white. It is of a similar 
 body and opacity, with darker 
 colour than Indian red, which has 
 also been classed among purples, 
 but in all other respects it re- 
 sembles that pigment. It may be 
 prepared artificially, and some na- 
 tural redochresburn to this colour, 
 which has been employed under 
 the denomination of violet de mar. 
 
 Purple wood is from the Brazils, im- 
 ported in logs from 8 to 12 inches 
 square, and 8 to 10 feet long, prin- 
 cipally used for ramrods, buhl- 
 work, marquetry, and turnery. 
 
 Purser, the cashier or paymaster of 
 mines ; also the paymaster of a 
 ship. 
 
 354 
 
 Pursuivant, in heraldry, a messenger 
 who formerly attended the king in 
 his wars, or at the council table, 
 and ultimately became herald. 
 
 Puteal, the enclosure surrounding 
 the opening of a well, to protect 
 persons from falling into it. It 
 was either round or square, from 
 3 to 4 feet high. There is a round 
 one in the British Museum, made 
 of marble. 
 
 Putlogs or Putlocks, in building, are 
 short pieces of timber about 7 feet 
 long, used in building scaffolds. 
 They lie at right angles to the wall, 
 with one of their ends resting upon 
 it, and the other upon the poles 
 which lie parallel to the side of the 
 wall of the building. 
 
 Putlog-holes, small holes left in walls 
 for the use of the workmen in 
 erecting scaffolding. 
 
 Putty, in the arts, a kind of paste 
 used by glaziers, composed of 
 whiting and linseed oil (with or 
 without white-lead), beaten toge- 
 ther to the consistence of a tough 
 dough. 
 
 Puzzolano, or Puozzolano, in mine- 
 ralogy, a volcanic sand of a violet 
 red colour (the jjiilrix I'uleoli of 
 Pliny), brought from Italy, which 
 forms a cement that hardens under 
 water. It appears to be a species 
 of argillaceous earth that probably 
 has been calcined and then ejected 
 from a volcano. Its constituents 
 are silex, alumina, oxide of iron, 
 and a little lime. It was first dug 
 out of the earth by the Romans 
 near the town of Puzzoli, not far 
 from Vesuvius. The environs of 
 Rome furnish it equally. It has 
 been found in France in the ex- 
 tinct volcanoes of Vivares. There 
 are a few regions exposed to ig- 
 neous agency which are destitute 
 of it, but it" presents itself under 
 very different physical appear- 
 ances, sometimes pulverulent, 
 sometimes in coarse grains, often 
 in slag, pumice, tufa, etc. Its 
 colour, which is generally brown, 
 passes to yellow, grey, and black. 
 
PYC 
 
 QUARRY. 
 
 QUA 
 
 The only preparation this material 
 undergoes previous to use is that 
 of pounding or grinding and sift- 
 ing, whereby it is reduced to pow- 
 der, in which state it is beaten to 
 a proper consistency with a due 
 proportion of lime, Artificial 
 puzzolano is also much used, and 
 is produced by pulverizing the 
 clay, the psammite, or the arene, 
 which is soluted, and the strewing 
 a layer of it, about four-tenths of 
 an inch, on a plate of iron, heated 
 to a point between a cherry-red 
 and forging-heat. It is left till it 
 be raised to the same degree, for 
 a space of time which varies, for 
 each kind of material, from five to 
 twenty minutes. It must be con- 
 tinually stirred with a small rod, 
 in order that the whole of the 
 particles may be uniformly cal- 
 cined. 
 
 Pycnostyle, that arrangement of 
 Greek or Roman columns, in 
 which the intercoluraniations are 
 equal to one diameter and a half 
 of the lower part of the shaft. 
 
 Pyramid, in geometry, is a solid 
 figure whose base is a polygon, 
 and whose sides are plane triangles, 
 their several points meeting in one. 
 
 Pyrites, in mineralogy, a name given 
 to certain metallic ores contain- 
 ing a large portion of sulphur ; 
 
 native compounds of sulphur with 
 different metals, and more espe- 
 cially with iron. The term is 
 derived from the use to which the 
 stone was formerly applied, that of 
 obtaining sparks by percussion, an 
 application of pyrites mentioned 
 by Pliny. 
 
 Pyrites, Copper, in mineralogy, a 
 combination (sulphuret) of copper 
 and sulphur, being the most com- 
 mon ore of copper. 
 
 Pyrites, Iron, in mineralogy, a com- 
 bination (sulphuret) of iron and 
 sulphur, one of the most abundant 
 minerals in nature. 
 
 Pyrometer, in chemistry, an instru- 
 ment for measuring very high tem- 
 peratures, depending on the uni- 
 form and permanent contraction 
 of pure clay. 
 
 Pyrometer, a contrivance for ascer- 
 taining the temperature of the 
 flues of boilers, by fixing an iron 
 wire at the back of the flue, and 
 connecting it to a lever in front of 
 the boiler, which indicates the de- 
 gree of expansion and consequently 
 the temperature. 
 
 Pyx, Pix, a tabernacle or shrine, a 
 depository for the Host, or con- 
 secrated wafer, used in Romish 
 ceremonies. (See Theoreca.} 
 
 Pyx, in navigation, the box in which 
 the nautical compass is suspended. 
 
 Q. 
 
 QUADRA, in architecture, a name 
 given by Vitruvius to the square 
 piece, commonly called the socle, 
 used to support the pedestals of 
 statutes, vases, and other orna- 
 ments. 
 
 Quadra, the bands or fillets of the 
 Ionic base, between which the 
 scotia or hollow occurs ; also the 
 plinth, or lower members of the 
 podium. 
 
 Quadrangle, a figure having four an- 
 gles and four sides. 
 
 Quadrant, the fourth part of a circle, 
 being bounded by two radii per- 
 pendicular to each other, and a 
 
 355 
 
 quarter of the circumference, or 
 90 degrees. 
 
 Quadrature, the finding a square 
 equal in area to another figure. 
 
 Quadrifores, folding - doors whose 
 height was divided into two. 
 Folding-doors which opened in 
 one height were termed fores val- 
 vatce, or valva. Vitruvius directed 
 the doorways to be made wider 
 when these were used, and the 
 height to be increased when the 
 folding - doors were divided in 
 height. The bifores of Vitruvius 
 were two single doors. 
 
 Quarry, a place underground from 
 
QUA 
 
 QUARTERS. 
 
 RAG 
 
 whence are taken marble, free- 
 stone, slate, limestone, and other 
 stones proper for building and 
 paving. 
 
 Quarry, a pane or piece of glass cut 
 in a lozenge or diamond form. 
 
 Quarter, in heraldry : this word is 
 sometimes used for an escutcheon 
 or coat of arms : there are sixteen 
 quarters required to prove nobility. 
 
 Quarter (ships), the afterpart of the 
 top-side. 
 
 Quarters, in building, those slight 
 upright pieces of timber placed be- 
 tween the puncheons and posts, 
 used to lath upon. These are of 
 two sorts, single and double : the 
 single quarters are sawn to 4 
 inches thick and 4 inches broad; 
 the double quarters are sawn to 4 
 inches square. It is a rule in car- 
 pentry that no quarters be placed 
 at a greater distance than 14 
 inches. 
 
 Quarter-deck, in ship-building, the 
 short upper deck from the after- 
 most end of the main chains to the 
 stern. 
 
 Quarter-gallery, the projecting con- 
 venience and ornament of the top- 
 side which is connected with the 
 stern. 
 
 Quarter-pieces, the carved figures at 
 the aftpart of the quarter-gallery 
 which joins to the taffrail, and 
 forms the boundary of the stern. 
 
 Quartering, in heraldry, the act of 
 dividing a coat of arms into four or 
 more quarters, by parting, couping, 
 etc., by perpendicular and hori- 
 zontal lines. The sovereign of Great 
 Britain in the first quarter bears 
 gules, the lions passant, or, etc.; in 
 the second, formerly, azure, three 
 fleurs-de-lis, etc. 
 
 Quatrefoil, an ornament of frequent 
 
 occurrence in Gothic architecture, 
 formed by a moulding disposed in 
 four segments of circles. 
 
 Quears, in mining, crevices in lodes. 
 
 Queen-post, a vertical timber, sup- 
 porting the rafters of a trussed 
 roof. 
 
 Quercitron Lake, or Quercitron Yel- 
 low, is what its name implies. It is 
 dark in substance, in grains of a 
 glossy fracture, perfectly transpa- 
 rent, and when ground is of a beau- 
 tiful yellow colour, more durable 
 than the common yellow lakes, al- 
 though not perfectly permanent. 
 
 Quick lime, such lime as is in the 
 caustic or most active state, and 
 which possesses the greatest power 
 of operating upon different sub- 
 stances with which it may come in 
 contact. It is quite the opposite 
 in its qualities and properties to 
 that which has fallen down into a 
 powdery state, in consequence of 
 being -saturated with water and 
 carbonic acid gas or fixed air, or 
 which is slaked and become effete. 
 
 Quick-work, the short pieces between 
 the ports withinside a ship. 
 
 Quink, in building, a piece of ground 
 taken out of any regular ground- 
 plot or floor : thus, if the ground- 
 plot be oblong or square, a piece 
 taken out of a corner to make a 
 court or yard, etc., is called a 
 quink. 
 
 Quirk, a small acute channel or recess, 
 much used between mouldings in 
 Gothic architecture : in Grecian ar- 
 chitecture ovolos and ogees are 
 usually quirked at the top, and 
 
 ' sometimes in Roman. 
 
 Quoins of stone, the corners of brick 
 or stone walls : when they stand 
 out beyond the brickwork, they 
 are called ' rustic quoins.' 
 
 E. 
 
 RABBET, that part of the keel, stern 
 and stern-post of a ship which is 
 cut for the plank of the bottom to 
 fit into ; the edges of plank or deal 
 for buydieads that are lapped one 
 
 over the other, and wrought square, 
 making each side of the bulkhead 
 a smooth surface to the distance of 
 two rooms and spaces. 
 Rack, in mining, an inclined plane on 
 
RAC 
 
 RAILWAYS. 
 
 RAI 
 
 which the ore and slime are washed 
 and separated. 
 
 Rack, a flat bar with teeth on one 
 side, to work into those of a pinion. 
 
 Racking, in mining, a process of se- 
 parating small ores from the earthy 
 particles by means of an inclined 
 wooden frame: the impurities be- 
 ing washed off, the ore remaining 
 near the head of the rock is taken 
 from thence, and undergoes toss- 
 ing. 
 
 Radiant point, any point from which 
 rays proceed. 
 
 Radius, in geometry, the semi-diame- 
 ter of a circle, or a right line drawn 
 from the centre to the line of cir- 
 cumference ; in anatomy, a bone of 
 the fore-arm, which accompanies 
 the ulna from the elbow to the 
 wrist. 
 
 Radius-rods, the guiding rods in a 
 parallel motion, jointed to the con- 
 necting-links, to counteract the 
 vibratory motion communicated by 
 the beam, by guiding the links so 
 that there is a point. 
 
 Rafters, in carpentry, the secondary 
 timbers of a house ; the timbers 
 let into the great beam. 
 
 Rag-stone, in mineralogy. The Kent- 
 ish rag-stone is a kind of lime- 
 stone, much preferred to other 
 stones of a similar nature. It is 
 found in beds varying from 6 inches 
 to 3 feet in thickness, and is com- 
 posed of the following substances : 
 carbonate of lime, with a little 
 magnesia, 92-6; earthy matter, C'5; 
 oxide of iron, 0*5 ; carbonaceous 
 matter, 0-4 = 100. This stone is 
 now much used. 
 
 Rail or life guards, in locomotive en- 
 gines, strong iron rods reaching 
 down within about 2 inches of the 
 rails, to catch and throw to one 
 side any obstruction which may be 
 on the rails. 
 
 Rails, the moulding ornaments in the 
 top-side, likewise in the head and 
 stern of a ship. 
 
 Railways : roads in which tracks of 
 iron or other smooth material are 
 laid for the easy passage of wheel- 
 
 carriages, appear to have been in- 
 troduced between the years 1600 
 and 1650, in the neighbourhood 
 of Newcastle, to facilitate the car- 
 riage of the coals from the pits, 
 in ' wains ' or waggons, to the 
 ' staythes' or discharging- places on 
 the Tyne. In 1676 they were de- 
 scribed to be thus formed : " The 
 manner of the carriage is by laying 
 rails of timber from the colliery to 
 the river, exactly straight and pa- 
 rallel ; and bulky carts are made, 
 with four rollers fitting those rails, 
 whereby the carriage is so easy, 
 that one horse will draw down 
 four or five chaldrons of coals." 
 These " rails of timber" were laid 
 upon transverse timbers or sleepers, 
 and secured with pegs of wood, the 
 sleepers being embedded in the 
 material of the roadway. 
 
 Before the year 1716, it became 
 the practice to preserve the edges 
 of the rails by nailing thin plates 
 of malleable iron upon their upper 
 surfaces in places where the draught 
 was harder than usual. About the 
 year 1767, cast-iron bars were sub- 
 stituted for the wooden rails, and 
 this change is said to have been 
 suggested by the wish of the iron- 
 masters to keep their furnaces at 
 work during a season of unusual 
 depression in the market value of 
 their manufactures. These iron 
 bars were found too valuable to 
 admit of a return to the wooden 
 rails, and improvements of various 
 kinds were introduced. Thus the 
 rails were cast in the form of long 
 narrow plates, with a vertical rim 
 along one side (the transverse sec- 
 tion resembling the form of the 
 letter L), and thus the wheels of 
 the waggons were retained in their 
 places without the projecting rims 
 or flanges which were required for 
 wheels running on the plain rails 
 or bars. These rails were called 
 1 tram' or plate rails,' and thus dis- 
 tinguished from subsequent forms 
 of iron rails which were introduced 
 to dispense with the longitudinal 
 
RAI 
 
 RAILWAYS. 
 
 RAI 
 
 timbers heretofore required benfiath 
 tbem, by casting the rails of suffi- 
 cient depth to carry their load, and 
 of reduced width, the flanged- 
 wheels being returned to. Mal- 
 leable-iron rails were introduced 
 about the year 1815, at coalworks 
 in Cumberland, with a view to re- 
 medy the defect of frequent break- 
 age, to which those of cast-iron 
 were liable : these malleable-iron 
 rails were simply bars of iron from 
 2 to 3 feet in length, and 1 to 2 
 inches square ; but the narrowness 
 of their surface was found to injure 
 the wheels so severely, that the 
 restoration of cast-iron rails ap- 
 peared likely, when an ingenious 
 invention was made by Mr. Birkin- 
 shaw, who obtained a patent in 
 October, 1820, for his improve- 
 ments, which consisted in passing 
 bars of iron,red-hot,between rollers 
 having indentations in their peri- 
 pheries, corresponding with the in- 
 tended shape of the rails. By this 
 mode malleable - iron rails were 
 rolled in lengths of 12 or 15 feet 
 each, and could be formed in any 
 required shape, the section varying 
 throughout the length, so as to 
 give increased depth and width at 
 the points intermediate between 
 the intended bearing places. The 
 rails now generally used are pro- 
 duced in a similar manner, and the 
 permanent way consists of a levelled 
 surface of roadway formed with 
 metalling or suitable ballasting, 
 transverse sleepers, commonly of 
 larch, about 9 feet in length, 8 to 
 10 inches in width, and about 6 
 inches deep. These sleepers are 
 laid from 2 feet 6 inches to 3 feet 
 apart, and saddles or chairs of cast 
 iron are fastened upon them with 
 spikes. Two of these chairs are 
 fixed upon each sleeper, at such 
 distance apart that the rails, when 
 placed in them, shall have the in- 
 tended distance or gauge between 
 them, commonly 4 feet 8 inches. 
 The rails are parallel throughout, 
 and of a form resembling that of 
 
 the letter K laid on one side, the 
 depth of the rail being about 5 
 inches, the width over the top and 
 bottom about 2| inches, and the 
 thickness of the middle vertical rib 
 about | inch ; all the angles of the 
 section being carefully removed by 
 rounding the meetings of the seve- 
 ral surfaces. For the ' broad gauge,' 
 in which the rails are laid 7 feet 
 apart, continuous longitudinal tim- 
 bers, about 12 inches square, are 
 employed, and connected by cross- 
 timbers framed to them. The rails 
 are of a bridged or arched section, 
 and rolled with a projecting plate 
 along each side, bolts passing 
 through which secure the rails to 
 the longitudinal timbers. 
 
 The theory of a perfect railway 
 requires that it should be level in 
 its vertical position and uniform in 
 direction. Practically, these con- 
 ditions are sacrificed within certain 
 limits; but the attainment of great 
 speed and safety, upon the present 
 Ipcomotive system, forbids any very 
 wide extension of them. The con- 
 sequence is, that great and expen- 
 sive works are required in earth- 
 works, bridges, viaducts, etc., to 
 obtain the required inclination ol 
 surface and direction ; and although 
 the principles of construction are 
 the same in all, hardly any two 
 railways are alike in details. 
 
 In 'the following Tables, the 
 principal particulars of main lines 
 branches, amalgamations, date of 
 acts of authority, length of each 
 portion, and total length of each 
 amalgamated line, with amount o 
 cost, or of estimate, or of capital 
 in round numbers, are arrangec 
 with the view of presenting a clear 
 outline of each railway, whethei 
 single or combined, arranged 
 nearly as practicable in a chronolo- 
 gical order; the earliest date of 
 the Act for any of the component 
 lines being adopted as the date for 
 determining the chronological place 
 for the amalgamated line in the 
 Table. 
 
RAT RAILWAYS. RA1 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 )ortion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 Severn and Wye . . . 
 
 1853 
 
 
 
 Estimate .... 37,620 
 
 (Originally Lydney and 
 
 
 
 
 
 Ledbrook) . . . 
 
 1809 
 
 
 
 
 Descending line^) 
 
 
 
 
 
 throughout from \ 
 Forest of Dean to f 
 Lydney Harbour. J 
 
 1853 
 
 3| 
 
 
 30,300 
 Parliam. Estimate . 48,974 
 
 Steepest grad. 1 in 40. 
 
 
 
 
 Stockton and Darlington 1842 
 
 401 
 
 
 
 For Tramroad from Ri- 
 
 
 1 
 
 
 
 ver Tees at Stockton 
 
 
 On I 
 
 90 
 
 , 
 
 to Witton Park Col- 
 
 
 ease i 
 _ ft 
 
 
 
 liery, with branches 
 
 
 50j 
 
 
 
 Lease of Middlesbro' 
 
 
 
 
 
 and Redcar Line . 
 
 1847 
 
 
 
 
 Lease of Wear Valley, 
 
 
 
 
 
 including Bishop 
 
 
 
 
 
 Auckland and Wear- 
 
 
 
 
 
 dale, Wear and Der- 
 
 
 
 
 
 went, Weardale Ex- 
 
 
 
 
 
 tension, Shildon 
 
 
 
 
 
 Tunnel .... 
 
 1847 
 
 
 
 
 Purchase of Middles- 
 
 
 
 
 
 bro' Dock, etc. . . 
 
 1849 
 
 
 
 
 Financial . 
 
 1851 
 
 
 
 
 Financial . 
 
 1852 
 
 
 
 
 Branch to Shildon ~| 
 Tunnel, new Ca- I- 
 pital, etc. . . . J 
 
 1854 
 
 
 
 / Authorized Cap. . 2,161,972 
 [Received . . . 2,061,329 
 
 Monkland. 
 
 
 
 
 
 Amalgamation of~] 
 the Monkland V 
 and Kirk . . . J 
 
 1824 
 
 
 
 /Shares. . . . 246,000 
 [Loans .... 82,000 
 
 
 
 
 
 /Shares. . . . 110,000 
 
 Ballochney .... 
 
 1826 
 
 
 
 [Loans .... 36,666 
 
 
 
 
 
 f Shares .... 210,000 
 
 Slamannan .... 
 
 1835 
 
 
 
 [Loans .... 70,000 
 
 Amalgamation . 
 
 1848 
 
 36 
 
 
 
 Five connecting Lines 
 
 
 
 
 
 viz. with the Edin- 
 
 
 
 
 
 burgh and Glasgow 
 
 
 
 
 
 Bathgate Minera 
 Fields, etc. . . 
 
 1853 
 
 N>i 
 
 46* 
 
 73,085 
 June 30, 1854 . . 594,446 
 
 London and N.-Western 
 
 1846 
 
 
 
 
 Amalgamation of the 
 Lond. & Birmingham 
 
 1833 
 
 1121 
 
 
 5,500,000 
 
 also of the 
 
 
 
 
 
 Warwick and Learn 
 
 
 
 
 
 ington, and 
 
 
 
 
 
RAI RAILWAYS. RAI | 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 jortion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 Lond. &N.-W. continued. 
 
 
 Mile*. 
 
 Miles. 
 
 4. 
 
 Peterboro* Branch, 
 
 
 
 
 
 amalgamated with 
 
 
 
 
 
 the London & Birm. 
 
 843 
 
 
 
 Amalgamated Cap. . 8,250,000 
 
 Grand Junction . . 
 
 833 
 
 86* 
 
 
 Original Capital. . 1,957,800 
 
 (with which was 
 
 
 
 
 Capital at amalga- 
 
 amalgamated in 
 
 
 
 
 mation of Chester 
 
 1840 the 
 
 
 
 
 and Crewe . . . 3,098,388 
 
 Chester and Crewe) . 
 
 837 
 
 20* 
 
 
 458,333 
 
 Bolton and Leigh . . 
 
 825 
 
 10 
 
 
 201,750 
 
 Huddersfld. & Manch. 
 
 845 
 
 
 
 
 Manchester & Birm. . 
 
 837 
 
 38* 
 
 
 2,800,000 
 
 Leeds, Dewsbury, and 
 
 
 
 
 
 Manchester . . . 
 
 845 
 
 
 
 799,300 
 
 North Union . . . 
 
 1831 
 
 22* 
 
 
 730,000 , 
 
 (joined with 
 
 
 
 
 
 Lane, and Yorksh. and 
 
 
 
 
 
 Preston and Wyre) . 
 
 1835 
 
 19* 
 
 
 400,000 
 
 "West London . . . 
 
 1836 
 
 3 
 
 
 280,000 
 
 Manchester, Buxton, 
 
 
 
 
 
 Matlock, & Midlds. 
 
 1846 
 
 111 
 
 
 421,300 
 
 North and South-wes- 
 
 
 
 
 
 tern Junction . . 
 
 1851 
 
 4 
 
 
 
 Birm., Wolverhampt., 
 
 
 
 
 
 and Stour Valley . 
 
 1846 
 
 
 
 1,110,000 
 
 Buckinghamshire . . 
 
 1846 
 
 41* 
 
 
 795,000 
 
 Shropshire Union . . 
 
 
 
 
 
 including the 
 
 
 
 
 
 Newton and Crewe . 
 
 1846 
 
 
 
 I United Capital f 1,500,000 
 
 Chester & Wolvrhmpt 
 
 1846 
 
 
 
 \ 3,300,000, \ 1,000,000 
 
 Shrewsby. & Stafford 
 
 1846 
 
 
 
 | viz.: . . . [ 800,000 
 
 Lancaster and Carlisle 
 
 
 
 
 Besides loans . . 1,099,999 
 
 Bedford .... 
 
 1845 
 
 15* 
 
 
 125,000 
 
 Branch from Black- 
 
 
 
 
 
 wall Line . . 
 
 1852 
 
 
 
 
 Besides powers for 
 
 
 
 
 
 new Lines, viz. : 
 
 
 
 
 
 Northampton & Mar- 
 
 
 
 
 
 ket Harborough 
 
 1853 
 
 18* 
 
 
 Estimate .... 250,000 
 
 St. Alban's . . . 
 
 1853 
 
 7* 
 
 
 Ditto .... 70,000 
 
 Shrewsbury & Crewe 
 
 1853 
 
 33 
 
 
 Ditto .... 350,000 
 
 Total length in ope 
 
 
 
 
 Total ShareCapital. 25,049,592 
 
 ration, 1854 . 
 
 
 
 553* 
 
 Debenture Debt . 9,993,448 
 
 
 
 
 
 Deb. 3* p. c. Stock . 402,830 
 
 
 
 
 
 Grand Total . . . 35,445,870 
 
 Newcastle and Carlisle 
 
 1829 
 
 
 78* 
 
 Capital .... 1,749,386 
 
 Branch to Alston . 
 
 
 
 
 
 Do. to Swalwell 
 
 
 
 
 
 360 
 
IAI RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 aortion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 West Hartlepool. 
 
 
 
 
 
 Incorporation of the 
 
 
 
 
 
 Stockton & Hartlepool 
 
 1842 
 
 8 
 
 
 
 Clarence 
 
 .829 
 
 37 
 
 45 
 
 
 Hartlepool West Har- 
 
 
 
 
 
 bour and Dock Co. 
 
 
 
 
 Total Capital . . 1,465,037 
 
 Dublin and Kingston 
 
 
 
 
 
 (Ireland). . . . 
 
 1831 
 
 6 
 
 
 
 Extension to Dalkey . 
 
 
 1* 
 
 
 Total Capital . . 290,000 
 
 Extension to Bray. . 
 
 1846 
 
 n 
 
 
 
 Hartlepool (leased to 
 
 
 
 
 
 York, Newcastle, and 
 
 
 
 
 
 Berwick 
 London and Greenwich . 
 
 1832 
 1833 
 
 16 
 
 H 
 
 
 Capital authorized . 531,400 
 993,000 
 
 London and S. -Western 
 
 
 
 
 
 London & Southampt. 
 
 1834 
 
 76| 
 
 
 2,100,000 
 
 Southampt. & Dorchr. 
 
 
 
 
 
 Branches to Hampton 
 
 
 
 
 
 Court, Chertsey, 
 
 
 
 
 
 Guildford, Farn- 
 
 
 
 
 
 ham, Alton; to Lon- 
 
 
 
 
 
 don, Brighton, and 
 
 
 
 
 
 S. Coast Railway . 
 
 
 
 
 
 Windsor, Staines, anc 
 
 
 
 
 
 South-western . . 
 
 
 
 267 
 
 Total Capital . . 8,856,48 i 
 
 North Union (1831, 22$ 
 
 
 
 
 
 miles), vested in Lon- 
 
 
 
 
 
 don and N. -western 
 
 
 
 
 
 and including the Wi- 
 
 
 
 
 
 gan and Preston anc 
 
 
 
 
 
 Wigan Branch . 
 
 1834 
 
 
 42 
 
 739,201 
 
 Great Western. 
 
 
 
 
 
 London to Bristol . 
 
 1835 
 
 118* 
 
 
 
 Slough to Windsor 
 
 
 3 
 
 
 
 Branch from Reading 
 
 
 
 
 
 to Basingstoke . 
 
 
 15| 
 
 
 
 Branch from Reading 
 
 
 
 
 
 to Hungerford 
 
 
 25| 
 
 
 
 Branch from Didcot 
 
 
 
 
 
 to Oxford. . . 
 
 
 10 
 
 
 
 Branch from Oxforc 
 
 
 
 
 
 to Fenny Compton 
 
 
 
 
 * 
 
 and Birmingham . 
 
 
 65 
 
 
 
 Branch from Swindon 
 
 
 
 
 
 to Gloucester . . 
 
 
 37 
 
 
 
 With branch to Ciren- 
 
 
 
 
 
 cester .... 
 
 
 4 
 
 
 
 Branch from Glouces- 
 
 
 
 
 
 ter to Cheltenham 
 
 
 7f 
 
 
 
RAI . RAILWAYS. KAlj 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 portion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 Gt. Western, continued. 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 Branch from Chippen- 
 
 
 
 
 
 ham to Westbury, 
 
 
 
 
 
 Frome, and War- 
 
 
 
 
 
 minster .... 
 
 
 23* 
 
 
 
 Branch from Glouces- 
 
 
 
 
 
 ter to Grange-Court 
 
 
 
 
 
 (Dean Forest) . . 
 
 
 7* 
 
 
 
 Total mileage now in 
 
 
 
 
 
 operation, including 
 
 
 
 
 
 the two Shrewsbury 
 
 
 
 
 
 lines (7 7 miles). . 
 
 
 
 419 
 
 Tot. authorized Cap. 23,927,827 j 
 
 Llanelly Railway & Dock. 
 
 
 
 
 
 Dock 
 
 1828 
 
 
 
 
 Railway 
 
 1835 
 
 26 
 
 
 
 New Branches . . . 
 
 
 71 
 
 33* 
 
 Authorized Capital 330,000 
 
 Arbroath and Forfar . . 
 
 1836 
 
 15* 
 
 
 Capital .... 230,350 
 
 Bristol and Exeter . . 
 
 1836 
 
 75* 
 
 
 
 Branch to Clevedon . 
 
 
 4 
 
 
 
 Do. Weston 
 
 
 1* 
 
 
 
 Do. Yeovil . . 
 
 
 19 
 
 
 
 Do. Tiverton . 
 
 
 5 
 
 105 
 
 Total Capital . . 3,535,794 
 
 Working (under lease) 
 
 
 
 
 
 also the Crediton 
 
 
 
 
 
 line 6 miles, and the 
 
 
 
 
 
 Somerset Central 
 
 
 
 
 
 line 12 miles. 
 
 
 
 
 
 Total worked by Bris- 
 
 
 
 
 
 tol and Exeter Co. 
 
 
 
 
 
 123 miles. 
 
 
 
 
 
 Dublin and Drogheda . 
 
 1836 
 
 31* 
 
 
 
 Branch to Howth 
 
 
 31 
 
 35* 
 
 
 Transfer of Navan 
 
 
 
 
 
 Branch .... 
 
 1846 
 
 
 
 Total Capital . . 835,000 
 
 Dundee and Arbroath . 
 
 1836 
 
 16f 
 
 
 140,000 
 
 Eastern Counties. 
 
 
 
 
 
 London to Colchester 
 
 1836 
 
 51 
 
 
 
 Northern and Eastern, 
 
 
 
 
 
 from Stratford to 
 
 
 
 
 
 Newport, with 
 
 
 
 
 
 branch to Hertford 
 
 1836 
 
 44 
 
 
 
 Length of Eastern 
 
 
 
 
 
 Counties proper 
 
 
 
 235 
 
 
 
 Norfolk line . . . 
 
 
 96* 
 
 
 - 
 
 Eastern Union . . . 
 
 
 95 
 
 
 
 Total under the united 
 
 
 
 
 
 management of the 
 
 
 
 
 
 three companies 
 
 
 
 426* 
 
 
 The same Union \vill 
 
 
 
 
 
 work also the 
 
 
 
 
 
 362 
 
RAI RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 portion. 
 
 Total 
 .length. 
 
 Estimate, Cost, or Capital. 
 
 Eastern Counties, con- 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 tinued. 
 
 
 
 
 
 Shepreth&HitchinlS^ 
 
 
 
 
 
 Newmarket and 
 
 
 
 
 
 Cambridge . .15 
 
 
 
 
 
 
 Newmarket&Bury 1 4-J 
 
 
 
 
 
 Harwich . . .12 
 
 
 
 
 
 Wisbeach Exten- 
 
 
 
 
 
 sion . . . . 2i 
 
 
 
 
 
 Hackney branch . 2f 
 
 
 
 
 
 East Anglian . 67 
 
 
 
 
 
 Tilbury ... 40 
 
 
 
 
 
 Beccles & Lowes- 
 
 
 
 
 
 toft . . . . 5f! 
 
 
 
 Exp. to June, 1854. 10,471,071 
 
 Hull and Selby . . . 
 
 1836 
 
 30| 
 
 
 
 Branch from Hull to 
 
 
 
 
 
 Bridlington . . . 
 
 
 
 61 
 
 
 
 
 
 
 ("Capital onwhich"! 
 
 (Rented to York & 1 
 North Midland) . J 
 
 1845 
 
 
 
 1 ****H 700,000 
 i Midland Co. f 
 
 
 
 
 
 L pays 10 p. c. J 
 
 Irish South-eastern. 
 
 
 
 
 
 Amalgamation . 
 
 1846 
 
 
 
 
 of the Great Leinster 
 
 
 
 
 
 and Munster from 
 
 
 
 
 
 Carlow to Kilkenny 
 
 1836 
 
 
 
 
 and Kilkenny to Clon- 
 
 
 
 
 
 mel 
 
 1846 
 
 
 
 
 and of the Wexford, 
 
 
 
 
 
 Carlow, and Dublin 
 
 1846 
 
 
 
 
 Total length first au- 
 
 
 
 
 
 thorized 89 miles, 
 
 
 
 
 
 subsequently re- 
 duced to .... 
 
 
 
 25 
 
 Cap. to June, 1854 270,343 
 
 London and Blackwall . 
 
 1836 
 
 
 9i 
 
 1,050,000 
 
 Midland. 
 
 
 
 
 
 Amalgamation of the 
 
 
 
 
 
 N. Midland from 
 
 
 
 
 
 Leeds to Derby . 
 
 1846 
 
 74| 
 
 
 
 MidlandCounties,from 
 
 
 
 
 
 Derby to Rugby 
 
 1836 
 
 58| 
 
 
 
 Birmingham & Derby 
 
 
 
 
 
 with fork line tc 
 
 
 
 
 
 London and North 
 
 
 
 
 
 western, atHamptor 
 
 1 183 
 
 481 
 
 
 
 Total amalgamatec 
 
 I 
 
 
 
 
 length, 18 H miles 
 
 
 
 
 
 The following lines ar< 
 
 i 
 
 
 
 
 alsoincorporated: 
 
 
 
 
 
 Bristol and Gloucester 
 
 
 
 
 
RAI RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts 
 
 Length 
 of each 
 portion 
 
 Total 
 Length 
 
 Estimate, Cost, or Capital. 
 
 Midland, continued. 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 and Birmingham 
 
 
 
 
 
 and Gloucester . . 
 
 
 95* 
 
 
 
 Sheffield &Rotherham 
 
 
 94 
 
 
 
 Leicester & Swanning- 
 
 
 
 
 
 ton 
 
 
 16 
 
 
 
 Leeds and Bradford 
 
 
 43 
 
 
 
 Total incorporates 
 
 
 
 
 
 lines 345J miles. 
 
 
 
 
 
 The following exten- 
 
 
 
 
 
 sions have been au- 
 
 
 
 
 
 thorized and con- 
 
 
 
 
 
 structed since the 
 
 
 
 
 
 amalgamation : 
 
 
 
 
 
 Syston &Peterborough 
 
 
 48 
 
 
 
 Nottingham& Lincoln, 
 
 
 
 
 
 & Southwell branch 
 
 
 36 
 
 
 
 Leicester and Swan- 
 
 
 
 
 
 nington Extension . 
 
 
 23* 
 
 
 
 Erewash Valley . . 
 
 
 21* 
 
 
 
 Nottingham & Mans- 
 
 
 
 
 
 field 
 
 
 12* 
 
 
 
 Mansfield & Pinxton . 
 
 
 7* 
 
 
 
 Total new branches, 149 
 
 
 
 
 
 miles. 
 
 
 
 
 
 Grand total length open 
 
 
 
 494i 
 
 Total Capital . . 18,685,299 
 
 North-Eastern. 
 
 
 
 
 
 Co prising the 
 
 
 
 
 
 York, Newcastle, and 
 
 
 
 
 
 Berwick. 
 
 
 
 
 
 Main line . . 151 
 
 
 
 
 
 Coal branches 
 
 
 
 
 
 in Berwick & 
 
 
 
 
 
 Durham . . 99i 
 
 
 
 
 
 Branches to Aln- 
 
 
 
 
 
 wick,&Wark- 
 
 
 
 
 
 worth,&Kelso 35 
 
 
 
 
 
 Branches in 
 
 
 
 
 
 Yorkshire . 44* 
 
 
 
 
 
 
 
 
 330 
 
 
 Computed Capital . 6,133,000 
 
 York & North Midland 
 
 183G 
 
 
 
 
 Main line, York, 
 
 
 
 
 
 Normanton, & 
 
 
 
 
 
 Knottingley . 26* 
 
 
 
 
 Branches toScar- 
 
 
 
 
 borough and 
 
 
 1 
 
 
 Whitby . . 53 
 
 
 
 
 Hull to Leeds . 50* 
 
 
 
 
 Short branches . 133 
 
 
 
 
 
 
 
 
 263 
 
 
 5,627,06 
 
 364 
 
IAI RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 jortion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 ^.-Eastern, continued. 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 Leeds Northern . . 
 
 1845 
 
 
 
 
 Main line, Leeds 
 
 
 
 
 
 to Stockton . 61 
 
 
 
 
 
 Branches . . 9 
 
 
 
 
 
 
 
 
 70 
 
 663 
 
 Computed Capital . 741,111 
 
 
 
 
 
 Computed Capital . 12,501,171 
 
 Sheffield, Rotherham, 
 
 
 
 
 
 Barnsley, Wake- 
 
 
 
 
 
 field, Huddersfield, 
 
 
 
 
 
 and Goole. 
 
 
 
 
 
 Sheffield & Rotherham 
 
 1836 
 
 
 5 
 
 268,798 
 
 Leased to Lancashire 
 
 
 
 
 
 and Yorkshire Co. 
 
 
 
 
 
 for 13,000 pr.ann. 
 
 
 
 
 
 South-Eastern. 
 
 
 
 
 
 South-Eastern original 
 
 
 
 
 
 line from Redhill 
 
 
 
 
 
 to near Dover . . 
 
 1836 
 
 66 
 
 
 
 London & Croydon . 
 
 1835 
 
 Bf 
 
 
 
 Extension into Dover 
 
 1843 
 
 
 
 
 Branch to Maidstone 
 
 1843 
 
 
 
 
 Bricklayers' Arms br. 
 
 1843 
 
 
 
 
 Canterbury, Ramsgate, 
 
 
 
 
 
 & Margate Extens. 
 
 1844 
 
 
 
 
 Folkestone branch and 
 
 
 
 
 
 Harbour .... 
 
 1844 
 
 
 
 
 Tunbridge Wells br. . 
 
 1845 
 
 
 
 
 Gravesend and Ro- 
 
 
 
 
 
 chester branches 
 
 1845 
 
 
 
 
 Minster & Deal, Ash- 
 
 
 
 
 
 ford & Hastings brs. 
 
 1845 
 
 
 
 
 Branches from Rye to 
 
 
 
 
 
 Rye Harbour, Tun- 
 
 
 
 
 
 bridge Wells to 
 
 
 
 
 
 Hastings, & " North 
 
 
 
 
 
 Kent " br. from the 
 
 
 
 
 
 junction with the 
 
 
 
 
 
 London and Green- 
 
 
 
 
 
 wich to Gravesend. 
 
 
 
 
 
 ExtensiontoRoches- 
 
 
 
 
 
 ter, over Canal . . 
 
 1846 
 
 
 
 
 Amalgamation of the 
 
 
 
 
 
 Reading, Guildford 
 
 
 
 
 
 &Reigate, the Whit- 
 
 
 
 
 
 stable & Greenwich 
 
 
 
 
 
 & Coal branch at 
 
 
 
 
 
 Charlton to Thames 
 Total length . . 
 
 1852 
 
 
 289f 
 
 Total Capital . . 10,903,892 
 
 SfiR 
 
RAI RAILWAYS. R.U 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 portion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 
 
 Miles. 
 
 Miles. 
 
 jt\ 
 
 Taff Vale 
 
 1836 
 
 31f 
 
 
 
 Leased in perpetuity, 
 
 
 
 
 
 the Aberdare . . 
 
 1845 
 
 H 
 
 
 66,600 
 
 Junction line with S. 
 
 
 
 
 
 Wales at Cardiff . 
 
 1852 
 
 12 
 
 
 
 Rhondda Valleys brs. 
 
 
 
 
 
 are completing. 
 
 
 
 
 
 Thames Haven . . . 
 
 1836 
 
 
 
 
 Renewed .... 
 
 1846 
 
 
 
 
 Railway from Eastern 
 
 
 
 
 
 Counties line at 
 
 
 
 
 
 Romford to Docks 
 
 
 
 
 
 at Shell Haven . . 
 
 
 16 
 
 
 300,000 
 
 Partly abandoned, in 
 
 
 
 
 
 favour of the Lond. 
 
 
 
 
 
 Tilbury, &Southend 
 
 1853 
 
 
 
 
 Ulster. 
 
 
 
 
 
 Belfast to Armagh 
 
 1836 
 
 36 
 
 
 719,590 
 
 West London. 
 
 
 
 
 
 Incorporated under the 
 
 
 
 
 
 titleof Birmingham, 
 
 
 
 
 
 B/istol, and Thames 
 
 
 
 
 
 Junction .... 
 
 1836 
 
 N 
 
 
 294,887 
 
 Lancaster and Preston 
 
 
 
 
 
 Junctions . . . 
 
 1837 
 
 20i 
 
 
 United Capital . . 567,772 
 
 London, Brighton, and 
 
 
 
 
 
 South Coast. 
 
 
 
 
 
 Amalgamation, 1846, 
 
 
 
 
 
 of the Croydon and 
 
 
 
 
 
 Brighton Cos., viz. 
 
 
 
 
 
 London and Croydon 
 
 1835 
 
 Bi 
 
 
 741,000 
 
 London and Brighton 
 
 1837 
 
 41* 
 
 
 2,400,000 
 
 Branches to Mitcham, 
 
 
 
 
 
 Epsom, Eastbourne, 
 
 
 
 
 
 Hailsham ,Horsham , 
 
 
 
 
 
 Lewes, Newhaven, 
 
 
 
 
 
 St. Leonards, Hast- 
 
 
 
 
 
 ings, Worthing, 
 
 
 
 
 
 Arundel, Chiches- 
 
 
 
 
 
 ter, & Portsmouth. 
 
 
 
 
 
 Crystal Palace branch 
 
 
 
 
 
 (opened June, 1854) 
 
 
 H 
 
 
 
 Total length produc- 
 
 
 
 
 
 ing revenue (of 
 
 
 
 
 
 which 7f miles be- 
 
 
 
 
 
 long to the South- 
 
 
 
 
 
 eastern, and 4 are 
 
 
 
 
 
 held jointly with the 
 
 
 
 
 
 South-western) 
 
 
 
 174 
 
 Total Capital . . 7,618,626 
 
 366 
 
IAI RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 portion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 ,. B. & S. C., continued. 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 United lines in con- 
 
 
 
 
 
 templation. 
 
 
 
 
 
 Wimbledon and Croy- 
 
 
 
 
 
 don (from Croydon 
 
 
 
 
 
 to Mitcham) Act . 
 
 1853 
 
 
 21 
 
 
 E. Grinstead agreed to 
 
 1853 
 
 
 7 
 
 
 Bognor do . 
 
 1853 
 
 
 6 
 
 240,000 
 
 Vlaryport and Carlisle . 
 
 1837 
 
 
 28 
 
 Exp. to Dec. 1853 . 458,179 
 
 Edinburgh and Glasgow 
 
 1838 
 
 
 46 
 
 1,200,000 
 
 Leasing the Stirling 
 
 
 
 
 
 and Dunfermline . 
 
 
 
 21 
 
 
 Polkemmet branch. 
 
 
 
 
 
 Cowlairs do. 
 
 
 
 
 
 Bathgate do. 
 
 
 
 
 
 Campsie do. 
 
 
 
 lit 
 
 Total Capital . . 3,290,849 
 
 \rdrossan . 
 
 1840 
 
 
 12* 
 
 Cost (to 1849) . . 100,950 
 
 Amalgamated with 
 
 
 
 *J 
 
 1 
 
 Glasgow and South- 
 
 
 
 
 
 western .... 
 
 1854 
 
 
 
 
 Norfolk. Amalgamation 
 
 
 
 
 
 (1845) of the Yar- 
 
 
 
 
 
 mouth and Norwich 
 
 1842 
 
 20 
 
 
 
 Norwich and Brandon 
 
 1844 
 
 271 
 
 
 
 Wymondham and 
 
 
 
 
 
 Dereham . . . 
 
 
 11* 
 
 
 
 Dereham & Fakenham 
 
 
 m 
 
 
 
 Branch to Halesworth 
 
 
 
 
 
 and Lowestoft . . 
 
 
 H 
 
 
 
 
 
 
 80J 
 
 Total Capital . . 2,221,163 
 
 South Wales Mineral . 
 
 1843 
 
 12* 
 
 
 Authorized Capital 113,000 
 
 Chester and Holyhead . 
 
 1844 
 
 85 
 
 
 
 Including the Mold 
 
 
 
 
 
 branch (from Ches- 
 
 
 
 
 
 ter to Mold) . . 
 
 1847 
 
 m 
 
 
 
 Bangor and Carnarvon 
 
 1851 
 
 7 
 
 
 
 From Chester & Holy- 
 
 
 
 
 
 head Railway, near 
 
 
 
 
 
 Bangor, to Carnar- 
 
 
 
 
 
 von, with a branch 
 
 
 
 
 
 to port of Dinorwie 
 
 
 
 105i 
 
 4,289,270 
 
 Colchester and Stour 
 
 
 
 
 
 Valley. 
 
 
 
 
 
 Leased to E. Union . 
 
 
 
 
 
 Sast Lancashire. 
 
 
 
 
 
 Amalgamation (1846) 
 of the Manchester 
 
 
 
 
 Capital Shares . . 300,000 
 
 Bury, & Rossendale 
 
 1844 
 
 14 
 
 
 Loans . . 100,000 
 
 Extension Act . . . 
 
 1846 
 
 10 
 
 
 Additional Shares . 530,000 
 
 
 
 
 
 Loans . 277,931 
 
RAI RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 
 of 
 Acts. 
 
 Length 
 of each 
 portion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 E. Lancashire, continued. 
 
 
 Miles. 
 
 Miles. 
 
 4. 
 
 Extension Act . . . 
 
 1847 
 
 6 
 
 
 Additional Shares . 300,000 
 
 (Besides branches). 
 
 
 
 
 Loans . 100,000 
 
 Blackburn & Preston 
 
 1844 
 
 * 
 
 
 Authorized Shares . 120,000 
 
 
 
 
 
 Loans . 40,000 : 
 
 Branches authorized . 
 
 1847 
 
 6 
 
 
 Additional Shares . 30,000 
 
 
 
 
 
 Loans . 10,000 
 
 Blackburn, Burnley, 
 
 1845 
 
 
 
 
 Accrington, & Colne 
 
 
 
 
 
 Extension, with a 
 
 
 
 
 
 branch eastward 
 
 
 
 
 
 through Burnley to 
 
 
 
 
 
 Colne, and 
 
 
 
 
 
 Liverpool, Ormskirk, 
 
 
 
 
 
 and Preston . . . 
 
 1846 
 
 36f 
 
 
 
 Total length autho- 
 
 
 
 
 
 rized (to June 30, 
 
 
 
 
 
 1854, SI! miles 
 
 
 
 
 
 were in operation) . 
 
 
 
 88 
 
 Exp. to June, 1854 3,869,004 
 
 Eastern Union. 
 
 
 
 
 
 Amalgamation, 1847, 
 
 
 
 
 
 of the E. Union 
 
 1844 
 
 18 
 
 
 
 (From Colchester to 
 
 
 
 
 
 Ipswich). 
 
 
 
 
 
 Ipswich and Bury . . 
 
 1846 
 
 27 
 
 
 
 Extension from Haugh- 
 
 
 
 
 
 ley to Norwich . . 
 
 
 4 
 
 
 
 Trowse br. opened 
 
 1852 
 
 2 
 
 
 
 
 (Connecting the 
 
 
 
 
 
 Ipswich and Bury 
 
 
 
 
 
 with the E. Union.) 
 
 
 
 
 
 Hadleigh branch . . 
 
 
 7 
 
 
 
 Sudbury branch . . 
 
 
 12 
 
 
 
 Total length autho- 
 
 
 
 
 
 rized about . . . 
 
 
 
 95 
 
 Ord. Share Capital. 1,206,900 
 
 Under the manage- 
 
 
 
 
 
 ment of the E. Coun- 
 
 
 
 
 
 ties (which see). 
 
 
 
 
 
 Great Southern and 
 
 
 
 
 Capital Shares . 3,602,381 
 
 Western .... 
 
 1844 
 
 
 
 Loans . 410,606 
 
 From Dublin to Cork, 
 
 
 
 
 
 passing near Portar- 
 
 
 
 
 
 lington, Thurles, 
 
 
 
 
 
 Tipperary, and Mal- 
 
 
 
 
 
 low, with a branch 
 
 
 
 
 
 to Carlow. 
 
 
 
 
 
 North British .... 
 
 1844 
 
 62 
 
 
 
 From Edinburgh to 
 
 
 
 
 
 Berwick (junction 
 
 
 
 
 
 with York, New- 
 
 
 
 
 
 368 
 
AT RAILWAYS. RAT 
 
 "Jame of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 
 Acts. 
 
 Length 
 of each 
 portion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 i. British, continued. 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 castle, & Berwick), 
 
 
 
 
 
 with branch to Had- 
 
 
 
 
 
 dington. 
 
 
 
 
 
 Edinburgh & Dalkeith 
 
 
 
 
 
 purchased . . . 
 
 1845 
 
 14 
 
 
 
 Br. to connect same . 
 
 1845 
 
 2 
 
 
 
 Edinburgh & Hawick 
 
 
 
 
 
 (powers transferred) 
 
 1845 
 
 43| 
 
 
 
 Branches to Selkirk, 
 
 
 
 
 
 Jedburgh, Kelso, 
 
 
 
 
 
 Tranent, Cockenzie, 
 
 
 
 
 
 North-Berwick, and 
 
 
 
 
 
 Dunse .... 
 
 1846 
 
 42 
 
 
 
 Deviation and short 
 
 
 
 
 
 extension .... 
 
 1847 
 
 
 
 
 Total length autho- 
 
 
 
 
 
 rized, of which 149 
 
 
 
 
 
 miles are now open 
 
 
 
 163 
 
 
 jancaster and Carlisle . 
 
 1844 
 
 
 70 
 
 Capital .... 1,613,903 
 
 Whitehaven Junction . 
 
 1844 
 
 12 
 
 
 Shares and Loans . 181,196 
 
 Shrewsbury and Chester ; 
 
 
 
 
 
 or N. Wales Mineral 
 
 
 
 
 
 from Chester to 
 
 
 
 
 
 Wrexham. 
 
 1844 
 
 
 
 
 Extended to Ruabon . 
 
 1845 
 
 
 
 
 Branches to Coal and 
 
 
 
 
 
 Mineral Works, nr. 
 
 
 
 
 
 Wrexham . . . 
 
 1846 
 
 
 
 
 Total about .... 
 
 
 
 25 
 
 
 South Devon .... 
 
 1844 
 
 
 
 
 From Exeter to Ply- 
 
 
 
 
 
 mouth. 
 
 
 
 
 
 Branches to Torquay 
 
 
 
 
 
 and other places 
 
 1846 
 
 
 
 
 Extension into Tor- 
 
 
 
 
 
 quay & to Brixham 
 'otal length authorized 
 
 1847 
 
 
 70 
 
 Capital .... 2,101,564 
 
 Aberdeen 
 
 1845 
 
 
 
 
 From Guthrie (Ar- 
 
 
 
 
 
 broath and Forfar) 
 
 
 
 
 
 to Aberdeen, with 
 
 
 
 
 
 branches to Brechin 
 
 
 
 
 
 and Montrose. 
 
 
 
 
 
 Total length,including 
 leased line . . . 
 
 
 
 72 
 
 Total Capital . . 1,760,932 
 
 Belfast and Ballymena . 
 
 1845 
 
 
 
 
 With branches to Car- 
 
 
 
 
 
 rickfergus and Ran- 
 dalstown . . . 
 
 
 38 
 
 
 Capital .... 385,000 
 
RAT RAILWAYS. RAT 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 portion. 
 
 Total 
 Length 
 
 Estimate, Cost, or Capital. 
 
 Belfast& Ballymena,eon/. 
 
 
 Miles. 
 
 Miles. 
 
 jtf. 
 
 Extension from Ran- 
 
 
 
 
 
 dalstown, through 
 
 
 
 
 
 Troome, Castle 
 
 
 
 
 
 Dawson, Maghera- 
 
 
 
 
 
 felt, & Moneymore 
 
 
 
 
 
 to Cookstown . . 
 
 1853 
 
 27 
 
 
 Estimate .... 192,500 
 
 Blackburn. 
 
 
 
 
 
 Amalgamation, 1846, 
 
 
 
 
 
 of 
 
 
 
 
 
 Blackburn, Darwen, 
 
 
 
 
 
 and Bolton and 
 
 1845 
 
 
 
 
 Blackburn, Clitheroe, 
 
 
 
 
 
 and N. W. Junction 
 
 
 
 
 
 Total length auth d . . 
 
 
 
 47 
 
 
 Caledonian 
 
 1845 
 
 
 
 
 Carlisle to Carstairs . 
 
 
 73* 
 
 
 
 Carstairs to Edinburgh 
 
 
 26* 
 
 
 
 Carstairs to Glasgow . 
 Cocker mouth and Work- 
 
 
 31* 
 
 
 Total Capital . . 7,877,413 
 
 ington .... 
 
 1845 
 
 8* 
 
 
 
 Branch from Marron 
 
 
 
 
 
 Foot to Bridgefoot . 
 
 1849 
 
 i 
 
 
 
 Cork and Bandon. 
 
 1845 
 
 
 
 
 Deviation & Extension 
 
 
 
 
 
 into Cork . . . 
 
 1848 
 
 20 
 
 
 
 Dublin&Belfast Junction 
 
 1845 
 
 56 
 
 
 Capital .... 1,042,365 
 
 Dundalk and Enniskillen 
 
 1845 
 
 
 
 Original Capital. 
 
 
 
 
 
 Shares . . 750,000 
 
 
 
 
 
 Loans . . 250,030 
 
 East Anglian. 
 
 
 
 
 
 Incorporation, 1847, 
 
 
 
 
 
 of the 
 
 
 
 
 
 Lynn and Ely, with 
 
 
 
 
 
 branch to Wisbeach 
 
 1845 
 
 36* 
 
 
 
 Lynn and Dereham . 
 
 1845 
 
 26* 
 
 
 
 Ely and Huntingdon . 
 
 1845 
 
 22f 
 
 
 Capital .... 1,329,745 
 
 Furness 
 
 1844 
 
 11* 
 
 
 
 Total length (of which 
 
 
 X l^f 
 
 
 
 
 20 are in operation) 
 
 
 
 22 
 
 Capital .... 396,841 
 
 Kendal and Windermere 
 
 1845 
 
 10* 
 
 
 Capital .... 215,519 
 
 From the Lancaster 
 
 
 
 
 
 and Carlisle at Oxen- 
 
 
 
 
 
 holme to Birthwaite, 
 
 
 
 
 
 near Windermere 
 
 
 
 
 
 Lake 
 
 1845 
 
 
 
 
 Leeds Northern 
 
 
 
 
 
 Extended to junction 
 
 
 
 
 
 with the Stockton 
 
 
 
 
 
 and Hartlepool . . 
 
 1846 
 
 
 
 

 :AI RAILWAYS. RAI 
 
 ^ame of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length Total 
 of each L e n gth. 
 portion. 
 
 : 
 
 Estimate, Cost, or Capital. 
 
 ,eeds Northern, cont. 
 
 
 Miles. 
 
 Miles. 
 
 ** 
 
 Powers to connect at 
 
 
 
 
 
 Melmerby with the 
 
 
 
 
 
 extension at North 
 
 
 
 
 
 allerton .... 
 
 1848 
 
 
 
 
 Branches to Harro- 
 
 
 
 
 
 gate, etc 
 
 1848 
 
 
 
 
 Total length . . . 
 
 
 
 71 
 
 
 Amalgamated with 
 
 
 
 
 
 N.-E. (which see) . 
 
 1854 
 
 
 
 
 lanchester South Junc- 
 
 
 
 
 Capital Shares . . 29,000 
 
 tion & Altrincham. 
 
 1845 
 
 
 
 Loans . . . 133,333 
 
 lidland Great Western 
 
 
 
 
 
 of Ireland . . . 
 
 1845 
 
 
 
 
 From Dublin to Mul- 
 
 
 
 
 
 lingarwith a branch 
 
 
 
 
 
 to Longford 
 
 
 
 
 
 Extended to Athlone. 
 
 1846 
 
 
 
 
 Extension to Port of 
 
 
 
 
 
 Galway .... 
 
 1847 
 
 
 
 
 Deviation of Extension 
 
 
 
 
 
 to Longford and 
 
 
 
 
 
 branch to Cavan . 
 
 1852 
 
 
 
 
 Total length autho- 
 
 
 
 
 
 rized 
 
 
 
 
 
 lonmouthshire . 
 
 1845 
 
 
 18H 
 
 Combined Capital . 2,128,578 
 
 ewry and Enniskillen . 
 
 
 45 
 
 
 Total Capital . . . 830,000 
 
 forth Devon (late Taw 
 
 
 
 
 Capital . . 119,814 
 
 
 Vale). 
 
 
 
 
 
 Incorporated 1838, & 
 
 
 
 
 
 revived .... 
 
 1845 
 
 
 
 
 From Crediton to 
 
 
 
 
 
 Barnstaple, with 
 
 
 
 
 
 branch to docks at 
 
 
 
 
 
 Freemington Pill. 
 
 
 
 
 
 Total open . . 
 
 
 32^ 
 
 
 
 Branch to Bideford 
 
 
 
 
 Capital .... 430,377 
 
 (promoted by the 
 
 
 
 
 
 " Bideford Exten- 
 
 
 
 
 
 sion Company ") in 
 
 
 
 
 
 course of construc- 
 
 
 
 
 
 tion 
 
 1853 
 
 6 
 
 38.1. 
 
 
 Oxford, Worcester, and 
 
 
 
 
 
 Wolverhampton. 
 
 1845 
 
 
 
 
 From Wolvercot near 
 
 
 
 
 
 
 Oxford junction 
 
 
 
 
 
 with Great Western, 
 
 
 
 
 
 through Worcester, 
 
 
 
 
 
 to Wolverharapton, 
 
 
 
 
 
 with branches . . 
 
 
 91 
 
 Cap. to June 1854. 3,437,676 
 
 371 
 
RAI RAILWAYS. KAI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date Length 
 of of each 
 Acts, portion 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 St. Helen's. 
 
 
 Miles. 
 
 Miles. 
 
 tt. 
 
 Amalgamation of the 
 
 
 
 
 
 Sankey Brook Na- 
 
 
 
 
 
 vigation, and St. 
 
 
 
 
 
 Helen's & Runcorn 
 
 
 
 
 
 Gap Railway . . 
 
 1845 
 
 7* 
 
 
 
 Branch from the ori- 
 
 
 
 
 
 ginal line atWidness 
 
 
 
 
 
 to Garston, 4 miles 
 
 
 
 
 
 south of Liverpool ; 
 
 
 
 
 
 and Docks at Gars- 
 
 
 
 
 
 ton 
 
 1846 
 
 n 
 
 
 
 Branches to Warring- 
 
 
 
 
 
 ton and Blackbrook 
 
 1847 
 
 4i 
 
 
 
 Branches to Rain ford 
 
 
 
 
 
 junction, and to the 
 
 
 
 
 
 Eccleston Coal 
 
 
 
 
 
 Fields, and minor 
 
 
 
 
 
 branches .... 
 
 1853 
 
 
 
 Total Capital . . 881,131 
 
 Scottish Central . . . 
 
 1845 
 
 
 
 
 Powers to construct 
 
 
 
 
 
 branches to Tilli- 
 
 
 
 
 
 coultry, Denny, and 
 
 
 
 
 
 Crieff, and minor 
 
 
 
 
 
 branches ending at 
 
 
 
 
 
 Perth 
 
 1846 
 
 
 
 
 Total length authoriz- 
 
 
 
 
 
 ed (of which 50i 
 
 
 
 
 
 miles are opened) . 
 
 
 
 62 
 
 Capital. 
 
 
 
 
 
 Consolidated Stock 1,020,000 
 
 
 
 
 
 Preference Shares 151,542 
 
 Scottish Midland Junct. 
 
 1845 
 
 
 
 
 Perth to Forfar . . 
 
 
 32* 
 
 
 
 Branch to Newtyle . 
 
 
 2 
 
 
 
 Branch from Coupar 
 
 
 
 
 
 Angus to Blair- 
 
 
 
 
 
 gowrie .... 
 
 1853 
 
 *i 
 
 
 
 Branch from Drum- 
 
 
 
 
 
 gley to Kirriemuir. 
 
 1853 
 
 3* 
 
 
 
 
 
 
 U| 
 
 Capital .... 711,230 
 
 
 South Wales .... 
 
 1845 
 
 
 
 
 From Fishguard' Bay, 
 
 
 
 
 
 Pembroke, and run- 
 
 
 
 
 
 ning thence along 
 
 
 
 
 
 .the northern shore 
 
 
 
 
 
 of the Bristol Chan- 
 
 
 
 
 
 nel, through Car- 
 
 
 
 
 
 marthen, Llanelly, 
 
 
 
 
 
 Swansea, Neath, 
 
 
 
 
 
 Cardiff, and New- 
 
 
 
 
 
 372 
 
RAI RAILWAYS. RAT 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 
 Acts. 
 
 Length 
 of each 
 portion . 
 
 Total 
 length. 
 
 
 
 Estimate, Cost, or Capital. 
 
 South Wales, continued. 
 
 
 Miles. 
 
 Miles. 
 
 rf. 
 
 port, to the west 
 
 
 
 
 
 bank of the River 
 
 
 
 
 
 Wye at Chepstow, 
 
 
 
 
 
 with branch from 
 
 
 
 
 
 Newport to Mon- 
 
 
 
 
 
 mouth. 
 
 
 
 
 
 
 Leased to Gt. West, in 
 
 1851 
 
 
 
 
 Length authorized . 
 
 
 
 169 
 
 
 Swansea to Chepstow, 
 
 
 
 
 
 opened June, 1851. 
 
 
 75 
 
 
 
 Grange Court to Chep- 
 
 
 
 
 
 stow, East, opened 
 
 
 
 
 
 19th Sept. 1851 . 
 
 
 19* 
 
 
 
 Swansea to Carmar- 
 
 
 
 
 
 then, opened llth 
 
 
 
 
 
 Oct. 1852 . . . 
 
 
 30 
 
 
 
 Carmarthen to Haver- 
 
 
 
 
 
 fordwest, opened 
 
 
 
 
 
 Jan. 1854 . . . 
 
 
 31 
 
 
 
 Forest of Dean, con- 
 
 
 
 
 
 verted from Tram- 
 
 
 
 
 Total capital. 
 
 way, July 1854 . . 
 
 
 H 
 
 
 Shares . . 2,444,250 
 
 Total length opened 
 
 
 
 
 
 163 miles . . 
 
 
 
 
 Loans, etc. . . . 1,423,997 
 
 Extension of Pem- 
 
 
 
 
 
 broke line, & branch 
 
 
 
 
 
 to Swansea Harbour 
 
 
 
 
 
 and Junction with 
 
 
 
 
 
 Newport and Ponty- 
 
 
 
 
 Estimated cost . . 170,000 
 
 pool .... 
 
 ift.^s 
 
 
 
 Power to borrow . 56,600 
 
 Waterford & Kilkenny .1845 
 
 
 
 
 From Waterford to 
 
 
 
 
 
 Kilkenny .... 
 
 
 31 
 
 
 
 with branch to Kells 
 
 
 6! 
 
 
 
 Total length autho- 
 
 
 
 
 
 rized 
 
 
 
 37| 
 
 Shares & Loans . 599,000 
 
 (of which, main line 
 
 
 
 
 
 31 miles are in 
 
 
 
 
 
 operation.) 
 
 
 
 
 
 Waterford & Limerick . 
 
 1845 
 
 
 
 
 Including branches . 
 
 
 
 75 
 
 Capital .... 1,132,538 
 
 Wear Valley. 
 
 
 
 
 
 Whitehaven & Furness . 
 
 1845 
 
 
 
 
 From Whitehaven to 
 
 
 
 
 
 a junction with the 
 
 
 
 
 
 " Whitehaven junc- 
 
 
 
 
 
 tion" at Whiteha- 
 
 
 
 
 
 ven, and a junction 
 
 
 
 
 
 with the Furness 
 
 
 
 
 
 373 
 
RAI RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date Length 
 of of each 
 Acts, portion. 
 
 Total 
 length. 
 
 Estimate, Cost, or Capital. 
 
 Whitehaven, continued. 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 at Foxwell, near 
 
 
 
 
 
 Broughton. 
 
 
 
 
 
 Total length . . . 
 Branch to harbour . 
 
 853 
 
 35 
 t 
 
 
 Capital authorized . 469,933 
 
 Ainbergate, Nottingham 
 
 
 
 
 and Boston, and E. 
 
 
 
 
 Junction .... 
 
 846 
 
 
 
 (Originally 90 miles 
 but reduced to . . 
 
 
 23 
 
 
 Fotal Capital . . 760,025' 
 
 viz. : from Grant- 
 
 
 
 
 
 ham to Colwick.) 
 
 
 
 
 
 Belfast & County Down 
 
 846 
 
 
 
 Average cost per mile, 
 
 
 
 
 
 15,520. 
 
 
 
 
 
 Buckinghamshire. 
 
 
 
 
 
 (Leased to London 
 
 
 
 
 
 andNorth-western), 
 
 
 
 
 
 Amalgamation 184 7 
 
 
 
 
 
 of the Buckingham 
 
 
 
 
 
 and Brockley . . 
 
 816 
 
 
 
 
 and the Oxford and 
 
 
 
 
 
 Bletchley . . . 
 
 1846 
 
 3H 
 
 
 
 Extension, north to 
 
 
 
 
 
 Banbury. Line from 
 
 
 
 
 
 Claydon to a junc- 
 
 
 
 
 
 tion with the Great 
 
 
 
 
 
 Western, Oxford, & 
 
 
 
 
 
 Rugby line, at Ban- 
 
 
 21} 
 
 53 
 
 Shares and Loans . 1,659,600 
 
 Caledonian and Dumbar- 
 
 
 
 
 
 tonshire Junction . 
 
 1846 
 
 
 
 
 Total in operation . 
 
 
 N 
 
 
 Capital Expended . 239,664 
 
 Cork, Blackrock, and 
 
 
 
 
 
 Passage . . . 
 
 1846 
 
 
 
 
 Cork to Passage West 
 
 
 6 
 
 
 
 Extension to Monk- 
 
 
 
 
 
 stone Baths (Main 
 
 
 
 
 
 lineopen. Extension 
 
 
 
 
 
 in abeyance) 
 
 
 H 
 
 
 
 Cornwall .... 
 
 1846 
 
 
 
 
 In connection with the 
 
 
 
 
 
 , South Devon at Ply 
 
 
 
 
 
 mouth,to Falmouth 
 
 
 
 
 
 with branches to 
 
 
 
 
 
 Padstow,totheLis 
 
 
 
 
 
 keard and Caradoc 
 
 
 
 
 
 and to the quays a 
 Truro and Penryn 
 
 
 
 83 
 
 Expen.toDec. 1853 540012 
 
 Works in Progress. 
 
 
 
 
 
 374 
 
IAI RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 gamation, Main line, 
 and Branches. 
 
 Date 
 
 of 
 Acts. 
 
 Length 
 of each 
 portion. 
 
 Total 
 length. 
 
 Estimate, Cost or Capital. 
 
 Deeside. Originally in- 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 corporated . . . 
 
 1846 
 
 
 
 
 Re-incorporated . . 
 
 1852 
 
 16* 
 
 
 Capital authorized . 141,650 
 
 Dublin and Wicklow, in- 
 
 
 
 
 
 corporated, as Water- 
 
 
 
 
 
 ford, Wexford, Wick- 
 
 
 
 
 
 low, & Dublin . . 
 
 1846 
 
 
 135 
 
 Reduced Capital . 500,000 
 
 Title altered & length 
 
 
 
 
 
 etc. reduced . . . 
 
 1851 
 
 
 
 
 Dundee & Perth, and 
 
 
 
 
 Capital. Shares . . 570,000 
 
 Aberdeen Junction . 
 
 1847 
 
 
 31f 
 
 Debentures 216,600 
 
 icneral Terminus and 
 
 
 
 
 
 Glasgow Harbour . . 
 
 1846 
 
 5 
 
 
 
 Jloucester and Dean 
 
 
 
 
 
 Forest .... 
 
 1846 
 
 16 
 
 
 Capital .... 279,000 
 
 Leased to Gt. Western 
 
 1854 
 
 
 
 
 Jreat North of Scotland 
 
 1846 
 
 
 138* 
 
 Capital .... 518232 
 
 40 miles between Aber- 
 
 
 
 
 
 deen and Huntley 
 
 
 
 
 
 completed 19 Sept., 
 
 
 
 
 
 1854. 
 
 1846 
 
 
 
 
 jreat Northern . . . 
 
 1846 
 
 
 
 
 London toAskern,near 
 
 
 
 
 
 York. 
 
 
 
 
 
 Total powers for 335 
 
 
 
 
 
 miles, of which 181 
 
 
 
 
 
 are abandoned, leav- 
 
 
 
 
 
 ing a total of . 
 
 
 
 154 
 
 Total Capital . , 11,128,025 
 
 Cillarney Junction . . 
 
 1846 
 
 41 
 
 
 Capital .... 247,932. 
 
 Worked by the Great 
 
 
 
 
 
 Southern & Western 
 
 
 
 
 
 lalton & Driffield June. 
 
 1846 
 
 24 
 
 
 Capital .... 287,014 
 
 Amalgamated with 
 
 
 
 
 
 North-eastern. 
 
 
 
 
 
 lanchester, Buxton, 
 
 
 
 
 Capital. Shares. . 453,750 
 
 Matlock,&Mid.Jn. 
 
 1846 
 
 
 
 Loans . . 151,250 
 
 (From Ambergate to 
 
 
 
 
 
 Rowsley) .... 
 
 
 lii 
 
 
 
 Worked by Midland 
 
 
 
 
 
 lanchester, Sheffield, & 
 
 
 
 
 
 Lincolnshire Amal- 
 
 
 
 
 
 gamation . . . 
 
 1846 
 
 
 
 
 Of the Sheffield, Ash- 
 
 
 
 
 
 ton-under-Lyne, & 
 
 
 
 
 
 Manchester ; the 
 
 
 
 
 
 Great Grimsby and 
 
 
 
 
 
 Sheffield Junction; 
 
 
 
 
 
 the Sheffield and 
 
 
 
 
 
 Lincolnshire ; the 
 
 
 
 
 
 Sheffield and Lin- 
 
 
 
 
 
 375 
 
 R 2 
 
RAI RAILWAYS. R VI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 portion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 Manchester, continued. 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 colnshire Extension, 
 
 
 
 
 
 and the GreatGrims- 
 
 
 
 
 
 by Dock Companies; 
 
 
 
 
 
 and (in 1847) of 
 
 
 
 
 
 the Manchester and 
 
 
 
 
 
 Lincoln Union . . 
 
 
 
 171| 
 
 Total Capital . . 8,137,451 
 
 Moray shire (from Stot- 
 
 
 
 
 
 field to Elgin) . . 
 
 1846 
 
 
 IH 
 
 Capital .... 41,616 
 
 Newmarket. From Ches- 
 
 
 
 
 
 terford Junct. (Eas- 
 
 
 
 
 
 tern Counties) to 
 
 
 
 
 
 Newmarket, etc. . 
 
 1846 
 
 23 
 
 
 
 Branch to Bury St. 
 
 
 
 
 
 Edmunds single line 
 
 
 14 
 
 37 
 
 
 Newport, Ahergavenny, 
 
 
 
 
 
 
 and Hereford . . 
 
 1846 
 
 33 
 
 
 
 Branch to the Tafi 
 
 
 
 
 
 Vale line .... 
 
 1847 
 
 16 
 
 
 Capital .... 628,245 
 
 Powers to make devia- 
 
 
 
 
 
 tions & short bran. 
 
 1853 
 
 
 
 
 Newry, Warrenpoint, & 
 
 
 
 
 
 Rostrevor . . . 
 
 1846 
 
 u 
 
 
 Capital .... 135,976 
 
 North London . . . 
 
 1846 
 
 7* 
 
 
 
 late East and West 
 
 
 
 
 
 India Docks, and 
 
 
 
 
 
 Birmingham Junct. 
 
 
 
 
 
 Branch to Blackwall 
 
 
 
 
 
 Extension near Bow 
 
 1850 
 
 
 
 Total Capital . . 1,198,661 
 
 North Staffordshire . . 
 
 1845 
 
 
 
 Total Capital . . 5,820,000 
 
 Length of Railway . 
 
 
 123 
 
 
 1 
 
 (besides 110 miles 
 
 
 
 
 
 of canal.) 
 
 
 
 
 
 North-western . . . 
 
 1846 
 
 
 
 Capital .... 1,159,754 
 
 Royston and Hitchin 
 
 1846 
 
 m 
 
 
 Capital .... 800,000 
 
 Extension to Bedford 
 
 1848 
 
 5 
 
 
 Works cost per mile 3,500 
 
 (leased to G. Nor.) 
 
 
 
 
 
 Shrewsbury & Birming- 
 
 
 
 
 
 ham with branches 
 
 
 
 
 
 to Madeley & Iron- 
 
 
 
 
 
 bridge .... 
 
 1846 
 
 293 
 
 
 Capital .... 1,344,787 
 
 Amalgamated with 
 
 
 
 
 
 Great Western. 
 
 
 
 
 
 Shrewsbury & Hereford 
 
 1846 
 
 
 
 Capital .... 600,000 
 
 South Staffordshire . . 
 
 1846 
 
 
 
 
 Amalgamation of the 
 
 
 
 
 
 South Staffordshire. 
 
 
 
 
 
 junction; and the 
 
 
 
 
 
 Trent Valley, Mid- 
 
 
 
 
 
 land, and Grand 
 
 
 
 
 
*AI 
 
 RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 
 Date 
 
 Length 
 
 Total 
 
 
 gamation, Main Line, 
 and Branches. 
 
 of 
 Acts. 
 
 of each 
 lortion. 
 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 5. Staffordshire, contin. 
 
 
 Miles. 
 
 Miles. 
 
 . 
 
 Junction ; besides 
 
 
 
 
 
 branches .... 
 
 
 
 
 Capital authorized . 1,260,000 
 
 Vale of Neath .... 
 
 1846 
 
 
 
 
 Line from Neath to 
 
 
 
 
 
 Merthyr Tydvil, 
 
 
 
 
 
 with branches to 
 
 
 
 
 
 the Aberdare, etc. 
 
 
 
 33 
 
 Total Capital . . 712,983 
 
 West Cornwall . . . 
 
 1846 
 
 
 
 
 From Carredas to Pen- 
 
 
 
 
 
 zance, with branch 
 
 
 
 
 
 to the Cornwall line 
 
 
 
 
 
 Length open . . 
 
 
 25 
 
 
 Capital .... 459,253 
 
 Birkenhead, Lancashire 
 
 
 
 
 
 & Cheshire Junct. 
 
 1847 
 
 
 
 
 Chester and Birken- 
 
 
 
 
 
 head amalgamated 
 
 1847 
 
 
 
 
 Re-incorporated 
 
 1852 
 
 
 
 Total Capital . . 2,323,319 
 
 jrlasgow and S.-Westerr 
 
 
 
 
 
 Amalgamation (1850) 
 
 
 
 
 
 of the Glasgow 
 
 
 
 
 
 Paisley, Kilmarnock 
 
 
 
 
 
 and Ayr; and the 
 
 
 
 
 
 Glasgow, Dumfries, 
 
 
 
 
 
 and Carlisle . . . 
 
 
 
 171| 
 
 Total Capital . . 4,090,000 
 
 Lancashire & Yorkshire. 
 
 1847 
 
 
 
 
 Amalgamation of the 
 
 
 
 
 
 Manchester &Leeds; 
 
 
 
 
 
 the Manchester,Bol- 
 
 
 
 
 
 ton and Bury; the Li- 
 
 
 
 
 
 verpool and Bury ; 
 
 
 
 
 
 the H uddersfield and 
 
 
 
 
 
 Sheffield ; theWake- 
 
 
 
 
 
 field, Pontefract, &. 
 
 
 
 
 
 Goole, and the West 
 
 
 
 
 
 Riding Union . . 
 
 
 
 253} 
 
 Total Capital . . 12,308,442 
 
 Liverpool, Crosby, and 
 
 
 
 
 
 Southport . . . 
 
 1847 
 
 
 18$ 
 
 Capital .... 300,000 
 
 Manchester & Southport 
 
 1847 
 
 
 
 Capital authorized . 1,033,300 
 
 South Yorkshire . . . 
 
 1847 
 
 
 
 
 Branches to Elescar & 
 
 
 
 
 
 Worsbro' . . . 
 
 1850 
 
 
 
 Capital .... 1,085,787 
 
 Bangor and Carnarvon 
 
 
 
 
 
 Amalgamated with 
 
 
 
 
 
 Chester &Holyhead 
 
 1851 
 
 7 
 
 
 
 East Suffolk. In corp 
 
 
 
 
 
 as the Halesworth 
 
 
 
 
 
 Beccles,&Haddiscoe 
 
 
 
 
 
 Worked jointly with 
 
 1851 
 
 
 
 
 the Norfolk by Act 
 
 1852 
 
 
 
 Capital Shares . . 450,000 
 
RAI RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 portion. 
 
 Total 
 Length. 
 
 
 Estimate, Cost, or Capital. 
 
 East Suffolk, continued. 
 
 
 Miles. 
 
 Miles. 
 
 4. 
 
 Alain line 
 
 
 24 
 
 343 
 
 Loans . 150 000 
 
 Branches .... 
 
 
 10| 
 
 01^ 
 
 
 Edinburgh, Perth, and 
 
 
 
 
 
 Dundee. 
 
 
 
 
 
 Re-incorporation . . 
 
 1851 
 
 
 90| 
 
 Total capital . . 3,161,263 
 
 Total length authord. 
 
 
 
 
 
 Length opened 71f m. 
 
 
 
 
 Capital .... 274,073 
 
 Hereford, Ross, & Glou- 
 
 
 
 
 
 cester 
 
 1851 
 
 23 
 
 
 
 North & South-western 
 
 
 
 
 
 Junction .... 
 
 1851 
 
 3| 
 
 
 Capital .... 83,810 
 
 St. Andrew's .... 
 
 1851 
 
 4* 
 
 
 Capital .... 25,000 
 
 Ulverstone & Lancaster. 
 
 1851 
 
 19 
 
 
 Capital .... 293,333 
 
 Warrington & Stockport 
 
 
 
 
 
 (late Warrington & 
 
 
 
 
 
 Altrincham Junct.) 
 
 1851 
 
 14 
 
 
 Capital .... 256,000 
 
 Waterford and Tramore 
 
 1851 
 
 in 
 
 
 Capital .... 56,343 
 
 Waveney Valley (Tivets- 
 
 
 
 
 
 hall to Bungay) . 
 
 1851 
 
 13* 
 
 
 
 Authorized extension 
 
 
 
 
 
 to the East Suffolk. 
 
 1853 
 
 6 
 
 19* 
 
 Authorized Capital. 155,699 
 
 Blyth and Tyne . . . 
 
 1852 
 
 13 
 
 
 
 Branches .... 
 
 1853 
 
 8* 
 
 21* 
 
 
 Leeds, Bradford, and 
 
 
 
 
 
 Halifax Junction . 
 
 1852 
 
 
 
 
 Branches to Ardsley 
 
 
 
 
 
 and Gildersome, etc. 
 
 1853 
 
 7 
 
 
 Capital .... 241,063 
 
 (WorKed by G. N.) 
 
 
 
 
 
 Leven 
 
 1852 
 
 6 
 
 
 
 London, Tilbury, and 
 
 
 
 
 
 Southend . . . 
 
 1852 
 
 40 
 
 
 Capital (Computed) 500,000 
 
 (Worked by E. C.) 
 
 
 
 
 
 Londonderry and Cole- 
 
 
 
 
 
 raine. Re-incorp. . 
 
 1852 
 
 37 
 
 
 Total Capital . . 565,OOC 
 
 Londonderry and Ennis- 
 
 
 
 
 
 killen. Re-incorp. 
 
 1852 
 
 
 60 
 
 Total Capital . . 590,849 
 
 Middlesbrough andGuis- 
 
 
 
 
 
 borough .... 
 
 1852 
 
 9 
 
 
 
 Br. to Cleveland Hills 
 
 1852 
 
 3 
 
 12 
 
 Capital .... 73,078 
 
 Somerset Central . . . 
 
 1852 
 
 
 12| 
 
 Capital .... 81,911 
 
 In course of construc- 
 
 
 
 
 
 tion, 1854. 
 
 
 
 
 
 Ballymena, Ballymoney, 
 
 
 
 
 
 Coleraine and Por- 
 
 
 
 
 
 trush Junction . . 
 
 1853 
 
 35 
 
 
 Estimate per mile . 4,000 
 
 Banbridge, Newry, Dub- 
 
 
 
 
 
 lin, & Belfast June. 
 
 1853 
 
 61 
 
 
 Estimate .... 35,000 
 
 Bedale and Levburn . 
 
 1853 
 
 11* 
 
 
 Do 44,000 
 
 Bideford Extension . . 
 
 1853 
 
 j. J.^ 
 
 6 
 
 
 Do 48,000 
 
 
 378 
 
RAI RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 portion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 
 1853 
 
 1853 
 1853 
 
 1853 
 1853 
 
 1853 
 1853 
 
 1853 
 1853 
 1853 
 
 1853 
 1853 
 1853 
 1853 
 
 1853 
 
 1853 
 1853 
 
 1853 
 1853 
 
 1853 
 1853 
 
 1853 
 1823 
 
 Miles. 
 5* 
 
 27} 
 
 22 
 
 8| 
 
 H 
 
 61 
 
 3H 
 
 29f 
 61 
 
 m 
 
 24| 
 26i 
 12* 
 
 51* 
 
 9 
 4 
 
 I*i 
 
 10 
 
 18* 
 
 hi 
 
 32} 
 
 22 
 
 Miles. 
 25 
 
 . 
 Estimate .... 27,000 
 
 Do 200 000 
 
 Boston, Sleaford, and 
 Midland Counties . 
 Chard 
 
 Do. .... 160 000 
 
 Coleford, Monmouth, 
 Usk, and Pontypool 
 Drieff Junction . . . 
 Darenth Valley (From 
 Dartford to Farn- 
 ingham) .... 
 East Grinstead . . . 
 East Kent (Strood to 
 Canterbury) . . . 
 Forth and Clide Junct. . 
 Hampstead Junction 
 (Projected as North 
 and South-western, 
 Hampstead, & City 
 Junction.) 
 Hull and Holderness 
 Limerick and Ennis . 
 Limerick and Foynes 
 Llanidloes and Newtown 
 Londonderry, Enniskil- 
 len, and Sligo . . 
 Londonderry and Lough 
 Swilly. . . . 
 
 Do 45 000 
 
 Do 40 000 
 
 Do 47 000 
 
 Do 437 837 
 
 Do 150,000 
 
 Do 250 000 
 
 Do. . . 110000 
 
 Do 150 000 
 
 Do 130 000 
 
 Do 66 000 
 
 Do 297 000 
 
 Do 39 000 
 
 Vletropol. Subterranean 
 Paddington to Gen. 
 Post Office . . . 
 Norwich and Spalding . 
 Branch to Wisbeach 
 Peebles. From Hawick 
 branch of North, 
 British to Peebles . 
 Port Carlisle. (Converted 
 canal) 
 
 Capital. Shares . 1,000,000 
 Loans . 333,000 
 
 Estimate .... 170,000 
 
 Capital .... 93,000 
 Do 194,477 
 
 Portsmouth. 
 Goldaming Station of 
 South- western to 
 Havant Junction 
 with London and 
 Brighton line, and 
 the Fareham Exten- 
 sion of London and 
 South-western and 
 direct to Portsmth. 
 toscrea & Parsonstown 
 Junction .... 
 
 Estimate .... 350,000 
 Do 100 000 
 
 
 379 
 
RAI RAILWAYS. RAI 
 
 Name of Railway, Amal- 
 gamation, Main Line, 
 and Branches. 
 
 Date 
 of 
 Acts. 
 
 Length 
 of each 
 potion. 
 
 Total 
 Length. 
 
 Estimate, Cost, or Capital. 
 
 St. Ives and West Corn- 
 wall Junction . . 
 Severn Valley .... 
 Staines, Workingham, & 
 Woking Junction . 
 Stamford and Essendine 
 Wellington & Severn Jn. 
 West of London and 
 Crystal Palace . . 
 Wimbledon & Croydon . 
 Worcester & Hereford . 
 Ayr and Maybole . . . 
 Bagenalstown and Wex- 
 ford 
 
 1853 
 1853 
 
 1853 
 1853 
 1853 
 
 1853 
 1853 
 1853 
 
 IS. VI 
 
 1854 
 1854 
 
 1854 
 1854 
 
 1854 
 1854 
 1854 
 
 1854 
 1854 
 1854 
 1845 
 1854 
 1854 
 1854 
 1854 
 1854 
 
 1854 
 1854 
 1854 
 1854 
 1854 
 
 1854 
 
 1854 
 1854 
 1854 
 1854 
 1854 
 
 1854 
 
 Miles. 
 
 4 
 40* 
 
 22| 
 3| 
 6 
 
 9* 
 
 M 
 
 30* 
 
 N 
 
 42* 
 26 
 
 M 
 
 25* 
 
 4* 
 
 3 
 
 15* 
 I 
 
 7$ 
 7| 
 
 15f 
 13* 
 16f 
 
 293 
 8* 
 
 18* 
 12 
 40^ 
 5* 
 
 m 
 
 10 
 22 
 1H 
 
 2| 
 6* 
 
 Miles. 
 
 . 
 
 Estimate. . . . 32,000 
 Do 560 000 
 
 Do 270 000 
 
 Do 46 500 
 
 Do 60 000 
 
 Do 360 000 
 
 Do ... . 45 000 
 
 Do. . . . 560 000 
 
 Capital .... 43,000 
 
 Estimate .... 270,000 
 Do 200 000 
 
 Border Counties . . . 
 Hexham to Falstone. 
 Bradford, Wakefield, & 
 Leeds 
 
 Do 180000 
 
 Carmarthen & Cardigan 
 Caterhara. To Brighton 
 line 
 
 Do 247 700 
 
 Do 30 000 
 
 Chipping Norton . . . 
 Cork and Youghal . . 
 Darlington and Barnard 
 Castle 
 
 Do 24 000 
 
 Capital .... 500,000 
 
 Estimate .... 100,000 
 Do 7 500 
 
 
 Hertford and Welwyn . 
 Horncastle & Kirkstead 
 Inverness and Nairn 
 Leominster and Kington 
 Mallow and Fermoy . . 
 N. York, and Cleveland. 
 Perth and Dunkeld . . 
 Potteries, Biddulph, and 
 Congleton . . . 
 
 Do 47 078 
 
 Do. . . . 45 000 
 
 Do 80 000 
 
 Do 106 000 
 
 Capital . . . . 133,000 
 Estimate .... 180.000 
 Do 70 000 
 
 Do 190 000 
 
 Capital .... 139,000 
 Do 533 333 
 
 Salisbury and Yeovil . 
 Selkirk and Galashiels . 
 Shropshire Union . . 
 Leased to L. & N. W. 
 South Devon &Tavistock 
 Stockport, Disley and 
 Wharley-bridge 
 Tralee and Killarney 
 Vale of Towy .... 
 Wells and Fakenham 
 Westminster Terminus . 
 Whitehaven, Cleator & 
 Egremont . . . 
 
 Do 32,000 
 
 Do 2,255,638 
 
 Estimate .... 154,000 
 Do 150,000 
 
 Do 110,000 
 
 Capital .... 78,000 
 Do, 93,000 
 Do . 640 000 
 
 Estimate .... 48,000 
 
RAT 
 
 RAIN-GAUGE. 
 
 RAI 
 
 Railway chairs, the pieces of cast- 
 iron which fix the rails to the 
 sleepers. 
 
 Rainbow, a meteor in the form of a 
 party-coloured arch or semicircle 
 exhibited in a rainy sky, opposite 
 to the sun, and caused by the 
 refraction of his rays in the drops 
 of falling rain : it never appears 
 greater than a semicircle, but often 
 much less : it is always double, 
 there being what is termed the 
 superior and inferior, or primary 
 and secondary rainbow: they al- 
 ways exhibit the seven prismatic 
 colours ; and the whole of this 
 phenomenon depends upon the 
 rays of the sun falling on spheri- 
 cal drops of water, and being in 
 their passage through them re- 
 fracted and reflected. 
 
 Rain-gauge, an instrument for mea- 
 suring the depth of rain that falls. 
 A very simple and excellent instru- 
 ment for this purpose is shown in 
 fig. 1. It consists of a copper 
 
 Fig. i. 
 
 funnel, from 5 to 7 inches diame- 
 ter. The rain being collected in 
 a glass bottle, this bottle should be 
 placed in a small stand near the 
 surface of the ground, to protect 
 the bottle from the action of the 
 
 sun. The amount of rain fallen in 
 a given time is measured in a 
 graduated glass jar, one-tenth the 
 area of the funnel, similar to that 
 shown in the figure, and so divided 
 that every inch in depth of the 
 tube shall indicate one-tenth of an 
 inch falling in the funnel. The 
 amount of rain falling can be mea- 
 sured by such an instrument to 
 T.-jith part of an inch, or even 
 less. 
 
 An instrument, fig. 2, is also 
 used for measuring the fall of rain. 
 It consists of a cylinder of copper 
 or other metal, from 5 to 7 inches 
 in diameter, and 30 inches long. 
 A float, just so much smaller as to 
 allow it to rise freely when it 
 becomes filled with water, is placed 
 within the cylinder, and to the 
 centre of the float is attached an 
 upright staff, marked in inches and 
 tenths of an inch, which, rising 
 through a hole at the bottom of 
 
 Fig. 2. 
 
 the funnel, as shown in the figure, 
 indicates the depth of rain received 
 into the gauge. 
 
 This instrument is very simple 
 and shows the amount of rain col- 
 lected upon mere inspection : it 
 
RAI 
 
 RATCHET. 
 
 REG 
 
 has, however, been proved that in 
 hilly districts and exposed situa- 
 tions, when the staff rises but a 
 small distance above the receiving 
 surface of the gauge, owing to the 
 rain being carried along with the 
 wind in a slanting, and frequently, 
 on the tops of high hills, almost in 
 a horizontal direction, that the 
 staff, though of small diameter, 
 arrests a large amount of rain, 
 which runs down the staff and 
 causes a much larger quantity to 
 be collected than is properly due 
 to the rain-fall. (Some interesting 
 experiments, showing the incor- 
 rect results given by these rain- 
 gauges, will be found in a ' Report 
 on the Supply of Surplus Water 
 to Manchester, Salford, and Stock- 
 port,' by S. C. Homersham, Civil 
 Engineer.) When these kind of 
 rain-gauges are used, the rod 
 should be movable, fitting loosely 
 the socket or the float, and only 
 placed in the gauge when the 
 depth of the rain-fall is to be 
 ascertained. 
 
 Rainline, a small rope, or line, some- 
 times used to form the sheer of a 
 ship, and to set the beams of the 
 deck fair. 
 
 Rake, in mining, an oblique vein. 
 
 Rake, in ship-building, an obtuse 
 angle, such as the stem and stern- 
 posts make with the keel of a 
 ship. 
 
 Rake of a ship, all that part of the 
 hull which hangs over both ends 
 of the keel. 
 
 Raking moulding, in joinery, a mould- 
 ing whose arrises are inclined to 
 the horizon in any given angle. 
 
 Ramp, in hand-railing, a concavity 
 on the upper side, formed over 
 risers, or over half or quarter span, 
 by a sudden rise of the steps 
 above, which frequently occasions 
 a knee above the ramp. 
 
 Rampant, in heraldry, a term applied 
 to a lion, leopard, etc., standing on 
 his hind legs, in the escutcheon, 
 with his forefeet reared up in the 
 posture of clawing. 
 
 382 
 
 Rampant Arch, one whose abutments 
 spring from an inclined plane. 
 
 Ranges, pieces fixed to the inside of 
 a ship to belay the ropes ; and 
 sometimes expressed for those be- 
 tween the ports whereon the shots 
 lie. 
 
 Rasp, a rough file. 
 
 Ratchell, loose stones. 
 
 Ratchet-brace, a tool for drilling a 
 hole in a narrow plane where there 
 is not sufficient room to use the 
 common brace : a ratchet-wheel is 
 fixed on the drill-socket, and turned 
 by a handle with a strong spring 
 attached to force round the socket 
 on the forward motion, and slips 
 over the teeth on the backward 
 motion. 
 
 Ratio is the relation of two quanti- 
 ties of the same kind with respect 
 to quality, and is divided into 
 arithmetical and geometrical. 
 
 Ratlines, in ship-rigging, small lines 
 that traverse the shrouds of a ship 
 horizontally, at regular distances, 
 and form ascending ladders to the 
 mast-head. 
 
 Rebate, a deep groove, or channel, 
 cut longitudinally in a piece of 
 timber to receive the edge of a 
 plank, or the ends of a number of 
 planks, which are to be securely 
 fastened in it. 
 
 Receiver of an air-pump, in pneu- 
 matics, a glass vessel placed on the 
 top of a plate, out of which the 
 air is exhausted by the pump. 
 
 Recess, a cavity in a wall, left either 
 for ornament or use when it is to 
 receive some furniture, as a side- 
 board, or to add to the quantity of 
 room ; and for ornament when 
 made in the form of a niche, to 
 give beauty and variety to the 
 building. 
 
 Reckoning, in navigation, the compu- 
 tation of a ship's way (usually by 
 the log), or the act of estimating 
 the distance run between one part 
 and another. 
 
 Reconciles, or Top Timber- Hollow, in 
 ship-building, a mould sometimes 
 used to form the hollow in the top- 
 
REG 
 
 RED-LEAD. 
 
 REF 
 
 side, which is called the reconciling 
 mould. 
 
 Rectangle, a right angle made by the 
 falling of one line perpendicularly 
 upon another. 
 
 Rectification, in chemistry, is the 
 repetition of a distillation or a 
 sublimation several times, in order 
 to render the substance purer and 
 finer, or freer from earthy and aque- 
 ous particles. 
 
 Rectification, in geometry, is the 
 finding of a right line equal to a 
 proposed curve, 
 
 Rectilineal, or Rectilinear, consisting 
 of right lines. 
 
 Rectory, a house for the residence of 
 the rector of a parish, usually situ- 
 ated near the church. 
 
 Red is the second and intermediate 
 of the primary colours, standing 
 between yellow and blue, and in 
 like intermediate relation also to 
 white and black, or light and 
 shade. Hence it is pre-eminent 
 among colours, as well as the most 
 positive of all, forming with yellow 
 the secondary orange and its near 
 relatives, scarlet, etc. ; and with 
 blue the secondary purple and its 
 allies, crimson, etc. It gives some 
 degree of warmth to all colours, 
 but most so to those which partake 
 of yellow. 
 
 Red-lead, Minium, or Saturnine red, 
 an ancient pigment, by some old 
 writers confounded with cinnabar, 
 and called Sinoper, or Synoper, is 
 a deutoxide of lead, prepared by 
 subjecting massicot to the heat of 
 a furnace with an expanded sur- 
 face and free accession of air. It 
 is of a scarlet colour and fine hue, 
 warmer than common vermilion ; 
 bright, but not so vivid as the bin- 
 iodide of mercury, though it has 
 the body and opacity of both these 
 pigments, and has been confounded 
 even in name with vermilion, with 
 which it was formerly customary 
 to mix it. When pure and alone, 
 light does not affect its colour; but 
 white-lead, or any oxide or prepa- 
 ration of that metal mixed with 
 
 it, soon deprives it of colour, as 
 acids do also ; and impure air will 
 blacken and ultimately metallize 
 it. 
 
 Red Ochre is a name proper rather to* 
 a class than to an individual pig- 
 ment, and comprehends Indian red, 
 light red, Venetian red, scarlet 
 ochre, Indian ochre, redding,. pud- 
 dle, bole, as well as other absurd 
 appellations, such as English ver- 
 milion, and Spanish buown, or 
 majolica. 
 
 Reef, in navigation, to contract a 
 sail by tying up a portion of it to 
 the yard. 
 
 Refectory, a refreshment-room ; the 
 hall or apartment in a monastery. 
 
 Refining and Puddling of Iron. The 
 chemical difference between cast- 
 iron and wrought-iron consists 
 principally in the difference of de- 
 gree in which foreign matters are 
 present in each, which is in larger 
 amount in the former than in the 
 latter. There are many cases in 
 which wrought-iron contains a 
 larger amount of impurities than 
 cast-iron, and is yet malleable ; 
 while cast-iron of the same com- 
 position may be very hard and 
 brittle. Berzelius detected in a 
 certain kind of bar-iron, 18 per 
 cent, of silex ; and yet this iron 
 was still malleable and useful. 
 One-tenth of that amount of silex 
 will make cast-iron brittle. The 
 foreign matters generally combined 
 with pig-iron are carbon, silicon, 
 silex, sulphur, phosphorus, arsenic, 
 zinc, manganese, titanium, chrome, 
 aluminium, magnesium, and cal- 
 cium. Each of these tends to 
 make iron brittle; therefore, in 
 converting cast into wrought iron, 
 it is necessary, as far as possible, 
 to remove them. Carbon and other 
 foreign matters divide the crude 
 iron into two very distinct classes. 
 In the one, carbon is only an acci- 
 dental mechanical admixture; in 
 the other, it is in definite chemical 
 combination. To the first belong 
 the white iron of heavy burden, 
 
REF 
 
 REFRACTION. 
 
 REF 
 
 and grey iron ; to the latter, the 
 white iron of small burden, or very 
 fusible ores. From the behaviour 
 of the different metals in the refin- 
 ing and puddling process, the pre- 
 sence of silicon and silex appears 
 to exert a similar influence : it is 
 not possible to remove silex from 
 white metal with 'which carbon is 
 chemically combined. The silex is 
 present in the form of silicon. 
 White metal of small burden may 
 contain from 5 to nearly 6 per 
 cent, of carbon ; and, if smelted 
 from pure ore, almost an equal 
 amount of other foreign matter, 
 such as silicon. Upon the pre- 
 sence and form of these its white 
 colour and crystallization in a de- 
 gree depend. Grey pig-iron seldom 
 contains more than 4'75 per cent, 
 of carbon, and generally only from 
 3-50 to 4 per cent. When carbon 
 is present to the amount of but 2 
 to 3 per cent., it becomes white. 
 The more this iron is stretched, 
 the more it forms fibres. Fibrous 
 bar-iron resembles hickory wood, 
 in the fact that it is a combination 
 of fibres and spaces. In bar-iron, 
 these spaces are filled with cinders, 
 and that portion of the iron is 
 proportional to the fineness of the 
 fibres. That portion of the iron 
 which is not melted, which crys- 
 tallizes too fast, or whose prema- 
 ture crystallization the workman 
 cannot prevent, is in the condition 
 of cast-metal, and cannot be con- 
 verted into fibrous wrought-iron. 
 In the puddling furnace it is ne- 
 cessary to prevent crystallization 
 by manual labour. This result, 
 whether in the Catalan forge, the 
 Woolfs oven, or the German forge, 
 is partly accomplished by the 
 blast. 
 
 Reflection is the return or regressive 
 motion of a movable body, arising 
 from the reaction of some other 
 body on which it impinges. 
 
 Reflex, in painting, denotes those 
 parts of a picture that are supposed 
 to be illuminated by a light re- 
 
 flected from some other body re- 
 presented in the piece. 
 
 Reflux, in hydrography, the ebb, back- 
 ward course of water, flux, or flow- 
 ing of the sea. 
 
 Refraction, in mechanics, the incur- 
 vation or change of determination 
 in the body moved. In dioptrics, 
 it is the variation of a ray of 
 light from that right line in which 
 it would have passed on, had not 
 the density of the medium turned 
 it aside. It is the bending of a ray 
 of light towards the perpendicular 
 when it passes intoadensermedium, 
 and from the perpendicular when it 
 passes into a rarer medium. 
 
 The law of refraction was first 
 completely established by Snell and 
 Descartes at the commencement of 
 the seventeenth century. The first 
 part of this law is similar to that 
 of reflection, viz. that the angles of 
 incidence and refraction (i. e. the 
 angles which the incident and re- 
 fracted ray each make with the per- 
 pendicular or normal of the surface, 
 or in this case the angles PCD and 
 p' c D") are both in the same plane. 
 Any ray meeting the surface of a 
 new medium is split into two rays, 
 one reflected and the other re- 
 fracted ; as, for instance, the ray 
 B c into the reflected ray c B', and 
 the refracted ray c B"; or n c into 
 the two rays c D' and c D". So 
 also a ray B" c will be partly re- , 
 fleeted in the direction c b', and 
 partly refracted into c B ; or D" c 
 will l)e reflected into c d f , and re- 
 fracted into c D. Now in all these 
 cases the three 'rays, incident, re- 
 flected, and refracted, will be all 
 in one plane, and that plane per- 
 pendicular to the acting surface 
 A A. 
 
 The angles of incidence and re- 
 flection (such as P c D and p c D') 
 are, as already explained, invariably 
 equal; but that of refraction (in 
 this case p' c D") is different from 
 both, but connected with them by 
 this law, that (at the same surface) 
 the sines of incidence and refraction 
 
IEF 
 
 REFRACTION. 
 
 REF 
 
 to the same radius bear a constant 
 ratio to each other, which is always 
 the same in the same two media. 
 
 D 
 
 For instance, in passing through 
 the surface AA, at whatever degree 
 of obliquity, and whether upwards 
 from the water into the air, or down 
 from the air into the water, a ray 
 is invariably so bent that the angle 
 it makes with the perpendicular 
 p p in the air may be greater than 
 that in the water; and that the 
 sine of the angle in air may be to 
 that in water (to the same radius) 
 as 4 to 3, which is the ratio that 
 has been determined by experi- 
 ment. At the surface separating 
 any other two media, a different 
 ratio would be observed with equal 
 constancy. 
 
 To find the new direction into 
 which any ray, such as D c, will be 
 bent by this surface, draw a circle 
 round the point c with any radius, 
 such as c s, and the sine of the ray 
 in air (to this radius) will be found 
 to be s s. Therefore the sine in 
 water will be ^ of s s. Draw a line 
 parallel with c p at a distance there- 
 from equal to f of s s, viz. at the 
 distance s' s", and as this intersects 
 the circle at s", the refracted ray 
 must pass through s" to make its 
 sine in water (s' s") f of its sine 
 in air (s s), both to the same radius 
 (c s, or c s"). If any other radius 
 be chosen, as c *, it is plain that 
 
 385 
 
 the same result will be obtained; 
 for, by the property of similar tri- 
 angles, if s' s" be f of s s, then 
 s' s" is also f of s s. 
 
 In tracing the course of a ray 
 upwards from the water, as D" c, 
 then, having found its sine in water 
 to any fixed radius, make its sine in 
 air greater, because the sine in 
 air is always greater than that in 
 water, as 4 : 3 ; and thus the new 
 direction of the ray will be found 
 to be c D. 
 
 In this case a very singular effect 
 takes place if the ray be very 
 oblique to the surface, as F c. It 
 should be remarked that no ray 
 passing from the air into the water, 
 however obliquely, could ever be 
 refracted into the direction c F, for 
 this reason, the sine of no angle 
 can be greater than the radius to 
 which it is drawn, therefore no ray 
 can have its sine to radius c s 
 greater than c s. But its sine in 
 water is only f of that in air, and 
 consequently cannot exceed f of 
 the radius. Now the sine of the 
 ray c F, viz. F z, is more than f of 
 the radius c s, therefore no degree 
 of obliquity of the ray in air will 
 enable it to become so oblique ir 
 the water as c F. But a ray may 
 ascend in the direction F c as well 
 as in any other. Now its sine in 
 air must become greater than F z ; 
 but this is impossible, for a line \ 
 longer than F z would be longer 
 than the radius c s, and therefore 
 too long to be the sine of any angle 
 to that radius. As this ray, then, 
 cannot be refracted according to 
 the law, it is not refracted at all, 
 but totally reflected in the direction 
 cf, the only known instance of to- 
 tal reflection, for none of the light 
 can penetrate the surface A A, which 
 is, in fact, absolutely opaque to this 
 light. This phenomenon of total 
 reflection may be seen by looking 
 through the side of a tumbler con- 
 taining water up to its surface, in 
 some such direction as / c, when 
 the surface will be seen to be 
 
REF 
 
 REFRACTION. 
 
 REF 
 
 opaque, and more reflective than 
 any mirror, inasmuch as the images 
 in it are perfectly equal in bright- 
 ness to the objects themselves. 
 
 Now at the surface between any 
 other two media, the ratio of the 
 sines would be different; for though 
 all surfaces reflect alike (as re- 
 gards the direction of the ray), 
 all do not refract alike. Suppose 
 the ray passed from vacuum into 
 water, the ratio would be rather 
 greater than 3 : 4, namely 1 : 1'335. 
 In passing from vacuum into air of 
 the common density, the refraction 
 would be much less, and conse- 
 quen tly he sines much more nearly 
 equal, viz. as 1 : 1-000294. Now 
 if the sine in any medium be called 
 1, the corresponding sine in vacua 
 is called the index of refraction of 
 that medium ; and is specific for 
 each substance, or as constant as 
 its density, expansibility, specific 
 heat, or any other measurable qua- 
 lity. Thus the refractive index of 
 air of the common density is 
 1-000294, that of water 1*335, of 
 crown glass 1-52, of flint glass 1-55. 
 
 In the case above considered, 
 of refraction from air into water, 
 and vice versa 1 , the sines in air and 
 in water are, strictly speaking, as 
 1-335 : 1-000294; and generally the 
 sines on each side of any surface 
 are inversely as the refractive in- 
 dices of the two media. 
 
 The refractive indices of a great 
 many media have been measured 
 and arranged in tables. When the 
 density of any substance is in- 
 creased or diminished, its refrac- 
 tive power is increased or dimi- 
 nished in the same ratio. 
 
 The application of the laws of 
 refraction accounts for numerous 
 deceptive effects seen in the atmo- 
 sphere, and included under the 
 general term mirage ; the most fa- 
 miliar of which is the distortion of 
 objects seen through a rising cur- 
 rent of hot air, which, from its 
 smaller density, has a lower re- 
 fractive power than the surround- 
 
 ing cold air, and therefore bends 
 the rays in various directions. It 
 is also plain that the rays of the 
 heavenly bodies coming from space 
 into our atmosphere must be re- 
 fracted, and thus cause the objects 
 whence they come to appear rather 
 above their true place, as the eye 
 at d in the figure sees D in the 
 direction d c rather above its true 
 place. This forms one of the 
 sources of error to be allowed for 
 in all astronomical observations, 
 and tables are calculated for finding 
 its amount, depending on the ob- 
 ject's apparent altitude, and the 
 state of the barometer and ther- 
 mometer. Owing to the very small 
 refractive power of air, however, 
 this error is hardly sensible when 
 the object is high, but increases 
 rapidly towards the horizon, where 
 it becomes 33', or rather more than 
 the sun's or moon's diameter, so 
 that these bodies may appear just 
 clear of the horizon when they are 
 really completely below it. As the 
 density of the air diminishes gra- 
 dually upwards, atmospheric re- 
 fraction is not, like that which has 
 been just considered, a sudden 
 change of direction, but the ray 
 actually describes a curve, being 
 refracted more and more at every 
 step ; and this applies equally to 
 the light from a distant terrestrial 
 object which is either lower or 
 higher than the eye, because it 
 must pass through air of constantly 
 increasing or diminishing density. 
 This refraction has therefore to be 
 allowed for in levelling, which is 
 done by assuming that the light 
 from a distant object comes to us 
 in a line arched or curved up- 
 wards, the radius of which is about 
 seven times that of the earth. 
 
 The application of these laws of 
 Dioptrics has also led to the un- 
 derstanding of the mechanism of 
 the eye, and hence to the imitation 
 thereof by lenses, affording the re- 
 medies for its infirmities of long 
 and short sight, and disclosing the 
 
 386 
 
EG 
 
 REGULATORS. 
 
 RET 
 
 wonders of the telescope and the 
 microscope. 
 
 egalia, in heraldry, ensigns of roy- 
 alty ; the apparatus used at a co- 
 ronation. 
 
 egardant, in heraldry, signifies look- 
 ing behind, as applied to a lion or 
 any other beast. 
 
 'egatta,ihe name of an aquatic spec- 
 tacle consisting of gondola races, 
 etc., exhibited at Venice. 
 
 '.eglet, a flat, narrow moulding, em- 
 ployed to separate panels or other 
 members ; or to form knots, frets, 
 and similar ornaments. 
 
 \egula, a band below the taenia of 
 the Doric epistylium, extending 
 the width of the triglyph, and 
 having six guttse depending from 
 it. It also signifies the space be- 
 tween two adjoining canals of the 
 triglyphs. 
 
 legular. In geometry, a regular body 
 is solid whose surface is composed 
 of regular and equal figures, and 
 whose solid angles are all equal. 
 There are five sorts : 1. A pyramid, 
 comprehended underfour equal and 
 equilateral triangles: 2. A cube, 
 whose surface is composed of six 
 equal squares : 3. That which is 
 bounded by eight equal and equi- 
 lateral triangles : 4. That which is 
 contained under twelve equal and 
 equilateral pentagons: 5. A body 
 consisting of twenty equal and equi- 
 lateral triangles. 
 
 Regulator, in mechanics, that part of 
 a machine which makes the motion 
 equable. 
 
 Regulator- cock, in locomotive en- 
 gines, a cock placed to admit oil 
 or tallow to lubricate the faces of 
 the regulator. 
 
 Regulator-cover, in locomotive en- 
 gines, the outside cover, remov- 
 able when required to examine the 
 regulator. 
 
 Regulator-shaft and levers, in loco- 
 motive engines, the shaft and levers 
 placed in front of the smoke-box 
 when each cylinder has a separate 
 regulator. A rod connected with 
 the shaft leads to the foot-plate, 
 
 where a handle is placed conve- 
 niently for use. 
 
 Regulator-valve, the valve in a steam- 
 pipe of a locomotive engine, for 
 regulating the supply of steam to 
 the cylinders. 
 
 Regulator-valve spindle, the spindle 
 for moving the regulator-valve ; 
 being fixed to it at one end, the 
 other end of the spindle passes 
 through a stuffing-box joint over 
 the fire-box, and has a handle 
 fixed on the end to turn it. 
 
 Relief-valve, a valve belonging to the 
 feeding apparatus of a marine en- 
 gine, through which the water 
 escapes into the hot well when it 
 is shut off from the boiler. 
 
 Relieving tackle, in mechanics, the 
 two strong tackles used to prevent 
 a ship's overturning on the careen, 
 and afterwards to assist in upright- 
 ing her. 
 
 Repercussion, in mechanics, the act 
 of drawing back ; rebound. 
 
 Replum, the panel of the impagis, or 
 horizontal rails of a framed door. 
 
 Repose, in painting, denotes certain 
 parts in the- composition of a pic- 
 ture which seem to tranquillize its 
 aspect. 
 
 Reredos, behind the back ; the back 
 of a fireplace ; also an altarpiece, 
 a screen, or partition wall. 
 
 Respond, in Gothic architecture, a 
 half-pillar or piece attached to a 
 wall to support an arch, etc. 
 
 Rest, in a lathe, a piece of iron to 
 hold the turning-tool upon, fixed at 
 the end of a slide by a set-screw : 
 the slide can be moved at right 
 angles to the bar of the lathe, and 
 the whole can be fixed at any part 
 of the bed, between the centres. 
 
 Reticulated work, a species of ma- 
 sonry or breakwork, formed ex- 
 ternally by small square stones or 
 bricks, placed lozengewise, and 
 presenting the appearance of net- 
 work. 
 
 Reticulation is the method of copy- 
 ing a painting or drawing by the 
 help of square threads. An open 
 frame is made similar to a strain- 
 
 387 
 
REV 
 
 REYNOLDS. 
 
 RHO 
 
 ing frame, and the painting en- 
 closed within it ; a number of 
 threads are then strained over at 
 equal distances, like network, 
 which are fastened to the frame by 
 nails. The canvas, or paper, is 
 likewise divided into an equal 
 number of proportional squares, 
 and whatever appears within the 
 square threads in the painting is 
 copied into the corresponding 
 squares on the canvas or paper. 
 The squares of the copy may bear 
 any proportion to those of the ori- 
 ginal. Painters often adopt this 
 method when they first execute a 
 small design, from which their large 
 and more finished work is copied. 
 
 Revels, or Reveals, the vertical re- 
 treating surface of an aperture, or 
 the two vertical sides of the aper- 
 ture, between the front of the wall 
 and the windows or door frames, 
 most commonly posted at right 
 angles to the upright surface. 
 
 Reversing gear, the apparatus for 
 reversing the motion of a marine 
 or locomotive engine, by changing 
 the time of action of the slide- 
 valve : the eccentric being in ad- 
 vance of the crank for the forward 
 motion will, if turned to an equal 
 distance behind the crank, produce 
 a backward motion. 
 
 Reversing handle and guide, the han- 
 dle placed beside the foot-plate 
 conveniently for use when re- 
 quired. The guide is a quadrant 
 fixed to the foot-plate, notched for 
 the end of the reversing handle for 
 each variation of the expansion 
 gear. To reverse the engine, the 
 handle is removed to any notch 
 past the centre of the guide on 
 the opposite side in which it was 
 before. Expansion is varied by 
 moving the handle from one notch 
 to another notch on the same 
 side of the centre of the guide 
 from which the engine is working. 
 When the handle is on the centre 
 notch, the handle is said to be out 
 of gear. 
 
 Reversing lever, the lever connected 
 
 388 
 
 to a crank on the reversing shaft 
 by a rod, and placed at the side of 
 the fire-box, between guide-plates 
 with notches to keep it vertical, 
 or in the forward or backward 
 position. 
 
 Reversing shaft, the shaft, with levers 
 on it, connected with the eccen- 
 tric rods in the rocking-shaft classj 
 but with the slide-valve rod in the] 
 expansion-gear class of engines. 
 Both arrangements effect the ob- 
 ject of moving the slide-valve so 
 as to admit steam to the contrary 
 side of the piston to which it had 
 previously been admitted, and thus 
 reverse its motion, and with it the 
 motion of the engine also. 
 
 Reversing valve. (See Air-valve.} 
 
 Reynolds (Sir Joshua) was born in 
 1723, in Devonshire. The price 
 Reynolds first received for a head 
 was five guineas. In 1755 (thirty- 
 two years of age) his charge was 
 twelve guineas. Some years after 
 his price for a head was twenty 
 guineas. In 1758, the account 
 of his studies and distribution of 
 time is curious. He received six 
 sitters daily. In 1760 he raised 
 his price to twenty-five guineas ; 
 at this he engaged several subor- 
 dinate labourers. His study was 
 about 15 feet high; the window 
 was small and square, and the sill 
 9 feet from the floor. His sitter's 
 chair moved on castors, and stood 
 above the floor 1^ feet. He wrought 
 standing, and with great celerity; 
 the handles of his brushes were 18 
 inches long. Reynolds again raised 
 his price for a portrait to thirty- 
 five guineas, and finally to fifty 
 guineas. 
 
 Rhomb, an oblique angled parallelo- 
 gram ; in geometry, a parallelogram 
 or quadrangular figure having its 
 four sides equal, and consisting of 
 parallel lines, with two opposite 
 angles and two obtuse. 
 
 Rhomboidal, approaching the shape 
 of a rhomb : in geometry, used to 
 signify an oblique-angled paralle- 
 logram. 
 
HU 
 
 ROADS. 
 
 ROA 
 
 humb, in navigation, a vertical cir- 
 cle of any given place, or the 
 intersection of a part of such circle 
 with the horizon. Rhumbs coin- 
 cide with the points of the world 
 or horizon, and are distinguished 
 like those of the compass. A 
 rhumb-line cuts all the meridians 
 under the same angle. 
 
 i&, in constructive architecture, a 
 moulding on the interior of a 
 vaulted roof. 
 
 'ib, an arch formed of a piece of 
 timber. 
 
 \ib, a pillar of coal left as a support 
 for the roof of a mine. 
 
 'i&s, arch-formed timbers, for sus- 
 taining the plasterwork of a vault, 
 or wood ceiling. 
 
 tibband, pieces of fir nailed to the 
 timbers of a square body under 
 which shores are fixed. 
 
 libbing, the whole of the timber- 
 work for sustaining a vaulted or 
 coved ceiling. 
 
 liders, in ship-building, interior ribs, 
 to strengthen and bind the parts of 
 a ship together, being fayed upon 
 the inside stuff, and bolted through 
 all. 
 
 lidge, the upper angle of a roof: tiles 
 called ridge -tiles are sometimes 
 made very ornamental. 
 
 digger, a wheel with a flat or slightly 
 curved rim, moved by a leather 
 band. 
 
 Right angle, in geometry, is that 
 formed by a line falling perpen- 
 dicularly on another, or that which 
 subtends an arc of ninety degrees. 
 
 Right line, in geometry, signifies the 
 same as a straight line, opposed to 
 curved or crooked. 
 
 Ring, in geometry, an annulus. 
 
 Ring-tail, in navigation, a quadrilate- 
 ral sail, occasionally hoisted abaft 
 the after-leech of the boom main- 
 sails, to which the fore-leech is 
 made to correspond. 
 
 Rising-rod, a rod in a Cornish engine 
 which rises by means of levers as 
 the cataract piston descends, and 
 lifts catches which release sectors, 
 and allow weights to shut or open 
 
 the steam, equilibrium, or exhaust 
 valve. 
 
 Rivets, short bolts of metal inserted 
 in a hole at the juncture of two 
 plates, and, after insertion, ham- 
 mered abroad at the ends, so as to 
 keep the plates together. Mr. Wm. 
 Fairbairn invented a riveting ma- 
 chine, which by the aid of steam 
 performs the work rapidly and 
 without noise. 
 
 Riveting Machine. The principle of 
 action of the riveting machine is 
 very similar to that of an ordinary 
 punching machine. The work per- 
 formed by it is usually done by 
 manual labour, which occupies a 
 much longer time, causes great 
 noise, and is much more expensive 
 and less efficient. The machine 
 consists of two strong side-frames 
 forming bearings for the fulcrum 
 for a powerful lever which works 
 between them, and is raised or 
 lowered by a cam acting at the ex- 
 tremity. On one end of the cam- 
 shaft is a large spur-wheel moved 
 by a pinion on the driving-shaft, 
 which has a very heavy fly-wheel 
 fixed on it, to accumulate power 
 and expend it during the action of 
 the lever. The riveting tool is 
 placed in a guide near the short 
 end of the lever, and directly op- 
 posite the end of the tool is ano- 
 ther, to form the heads fixed on a 
 pillar called the riveting block. The 
 rivet being made to enter the holes, 
 and placed between the riveting 
 tool and the block, the machine 
 is set in motion, and the cam 
 raises the lever, which presses 
 against the tool and instantly forms 
 the rivet. 
 
 Roads are artificially - formed ways 
 bet veen distant places, and being 
 among the first means of personal 
 communication, their formation 
 and treatment, as duties of the 
 engineer, are of the highest im- 
 portance. The efficiency of road- 
 making requires that the surface of 
 the road shall be preserved in a 
 durable condition, and adapted for 
 
 389 
 
ROA 
 
 ROADS. 
 
 ROA 
 
 the kind of traffic to be conducted 
 upon it; and, therefore, the con- 
 struction of the road, both as re- 
 gards its superstratum or surface, 
 and substructure, its dimensions 
 and inclination, or declivity, are 
 equally to be determined with re- 
 ference to the particular kind of 
 wear to which it will be subjected. 
 Thus the weights that will pass 
 over the road will make it neces- 
 sary that it possess greater or less 
 firmness and solidity, while the 
 rigidity or hardness of its surface 
 affects the power required for mov- 
 ing bodies, or the draught. The 
 vertical inclination of the road has 
 an influence upon the draught, and 
 is also limited by the class of traffic. 
 The old Roman roads, for instance, 
 designed for the passage of animals 
 only, were laid with inclinations of 
 great steepness, and with reference 
 only to the directness of their 
 course. The u<,e of wheel carriages 
 imposes limits to the steepness 
 which cannot be exceeded either 
 with safety or with economy of 
 power. The most improved form 
 of road the railway restricts the 
 steepness or inclination still further, 
 the propelling power employed 
 being found to become expensive 
 in a rapid ratio in proportion to the 
 departure of the surface on which 
 it is exerted from a horizontal 
 plane. The qualities of a good 
 road are, solidity of structure, 
 hardness of surface, levelness of 
 inclination, and sufficiency of width 
 for all its purposes. To ensure the 
 permanence of these qualities, the 
 formation and the drainage of the 
 road are required to be complete, 
 while the several means to be 
 adopted will be partly determined 
 by the kind of materials at com- 
 mand. Experiments made to as- 
 certain the force of traction on dif- 
 ferent kinds of roads, have shown 
 that this force is nearly in exact 
 proportion to the strength and 
 hardness of the road. Thus the 
 draught on a well-made pavement 
 
 is half that upon a broken stone 
 surface", or old flint road, and less 
 than a quarter of the draught upon 
 a gravel road. If the strength or 
 solidity of the foundation be in- 
 creased, the draught is reduced. 
 Thus, if the broken stone road be 
 laid upon a rough pavement foun- 
 dation, the draught is reduced one- 
 third, and a similar reduction is 
 effected by laying a bottoming oi 
 concrete formed of cement and 
 gravel. The external forces by 
 which the motion of bodies upon 
 roads is retarded, and the draught 
 or power required consequently 
 augmented, are collision, friction, 
 gravity, and the atmosphere. Col- 
 lision is occasioned by the bard 
 protuberances and irregularities ol 
 surface of the road meeting the 
 wheels, and thus diminishing the 
 momentum of carriages. The re- 
 sistance arising from collision is 
 proportional directly to the load 
 and the height of the obstacle tc 
 be surmounted, and inversely tc 
 the diameter of the wheels of the 
 carriage in which the load is borne. 
 Professor Leslie has defined the 
 resistance which friction causes to 
 consist " of the consumption of the 
 moving force, or of the horse's 
 labour, occasioned by the soft sur- 
 face of the road, and the continu- 
 ally depressing of the spongy and 
 elastic substrata of the road." From 
 the formula which have been de- 
 duced upon the extent of this re- 
 sistance, it is evident that it is 
 caused by the wheels sinking intc 
 the ground, and is proportional di- 
 rectly to the load, and inversely tc 
 the width of the wheels. The re- 
 sistance produced by gravity is evi- 
 dently in proportion to the steep- 
 ness of the road, being nothing or 
 a perfectly horizontal plane, anc 
 augmenting as the inclination ap- 
 proaches the perpendicular. The 
 force of the air in resisting the 
 motion of loads upon roads may be 
 understood from the experiment! 
 which are given in Smeaton's Re- 
 
 390 
 
,OA 
 
 ROCKING-SHAFT. 
 
 ROC 
 
 ports, and from which it appears, 
 that upon a surface of one square 
 foot this force equals 1 Ib. when 
 the velocity of the wind is at the 
 rate of 15 miles per hour ; and that 
 this force becomes equal to 12 Ibs. 
 when the air moves at the rate of 
 50 miles an hour, constituting a 
 storm. 
 
 In designing a road, a correct 
 survey of the proposed line, with 
 the exact relative levels of all parts 
 of its present surface is the first 
 requisite, and upon this the engi- 
 neer proceeds to consider the pro- 
 priety of deviating in one direction 
 or another, in order to attain better 
 levels, or to equalize the earth- 
 works, so that the quantity exca- 
 vated in one part may suffice to 
 embank an adjacent portion, and 
 thus reduce the distances to which 
 the soil must be removed. In de- 
 termining the inclinations of the 
 surface, facts proved by experience 
 should be consulted, from which 
 the rule may be inferred that an 
 inclination of 1 in 35 is that which 
 admits of horses moving with per- 
 fect safety in a fast trot. Valleys 
 are required to be crossed by 
 bridges and viaducts, or solid em- 
 bankments and hills are excavated 
 with cuttings or with tunnels to 
 reduce the elevation to which it 
 would otherwise be necessary to 
 carry the road. Streams and rivers 
 are also occasionally to be passed 
 over, and thus the design and exe- 
 cution of an extended length of 
 road frequently involves some of 
 the grandest works of engineering 
 art. 
 
 Road-making was a principle of 
 employment ingeniously carried out 
 by Napoleon in those countries 
 mastered by his arms ; he disco- 
 vered one element of the mixing of 
 the poorer population by the mono- 
 polies and greediness of the rich ; 
 his master mind saw clearly that he 
 could not better secure his power 
 than by employing the unfortunate 
 and labouring poor. Road-making 
 
 391 
 
 zealously occupied his mind : his 
 name to this day, for this simple 
 and important fact, is revered. In 
 those towns on the Continent where 
 a resume existed of the antagonistic 
 principle, it is obvious that pau- 
 perism may be staved off by the 
 more wealthy lords of the soil, if 
 they give employment to the poor; 
 and such conduct on the part of 
 Napoleon naturally produced a ve- 
 neration for his name. These poor 
 people desired no cold charity; they 
 sought for sustenance by the means 
 of useful labour ; and one of these 
 was road-making. Many of them 
 cheerfully shouldered the musket 
 for the man who had so cherished 
 them. Among the great projects 
 carried out may be mentioned the 
 Simplon road, from Geneva to Mi- 
 lan, which cost the French Govern- 
 ment seventeen millions of livres, 
 about 650,000. 
 
 Roasting of Iron Ore is either to 
 produce higher oxidation, or to 
 expel injurious admixtures. In 
 both cases, liberal access of at- 
 mospheric air is required. Ore to 
 be roasted should be broken into 
 pieces as small as those usually put 
 into the blast-furnace. The kind 
 of fuel required is wood, and small 
 charcoal, turf or peat, or brown 
 coal, may be used. There are many 
 different forms of ovens used ; all 
 of them can be reduced to that of 
 the blast-furnace or the lime-kiln. 
 These ovens are commonly from 
 twelve to eighteen feet high, and 
 contain from fifty to one hundred 
 tons of ore at one time. 
 
 RocMng-shaft, the shaft, with levers 
 on it, which works the slide-valves 
 in some steam engines. The ec- 
 centric-rod drops on to a stud fixed 
 in one lever, and the links of the 
 slide-valve rod are attached to the 
 opposite lever on the same shaft. 
 This mode of working the slide- 
 valves was generally adopted be- 
 fore the introduction, by Mr. Ste- 
 phenson, of the direct-action mode 
 of working them. 
 
ROD 
 
 ROMAN ARCHITECTURE. 
 
 ROM 
 
 Rod, or pole, a long measure of 16^ 
 linear feet, or a square measure of 
 272 square feet. 
 
 Roller, a solid cylinder of metal or 
 wood, used for many purposes. 
 
 Rolling Machine, an invention for 
 making the brass mouldings in 
 fenders, and the brasswork in 
 grates. 
 
 Rolling Mitt,a. mill for reducing masses 
 of iron, copper, or other metals, to 
 even parallel bars or thin plates. 
 This is effected by passing the me- 
 tal, whilst red-hot, between two 
 cylindrical rollers of steel, put in 
 motion by the mill, and so mounted 
 in a strong metal frame that they 
 cannot recede from each other. 
 
 Roll-moulding, a moulding used in 
 early English architecture, resem- 
 bling a roll. 
 
 Roman Architecture, in its masonry, 
 both in public and private build- 
 ings, was of far more durable cha- 
 racter and more accurate workman- 
 ship in the earlier periods than at 
 the decline of the empire. It began 
 with uncemented blocks of stone, 
 passed into the reticulated work of 
 the Republic, thence into the tra*- 
 vertine, and descended into a mix- 
 ture of turf and brick, and stucco 
 facing. The polyhaedral wall, or, 
 as it is often named, the Cyclopean, 
 is the oldest example of masonry 
 in Italy ; but this style of building 
 has been used in town walls only. 
 Until about the middle of the 
 last century, Roman architecture 
 was regarded as the Antique and 
 the Classical par excellence, and 
 was supposed to exhibit the most 
 refined taste and most perfect ar- 
 tistic propriety. The ' Orders,' as 
 practised by the Romans, were the 
 examples taken up and followed by 
 the Italian masters at the period of 
 the so-called Revival, and still con- 
 tinue to be followed, both in that 
 country and in France, in prefer- 
 ence to their Greek prototypes. 
 Among ourselves, however, the 
 Roman style has of late years fallen 
 somewhat into discredit, at least 
 
 as far as the orders are concerned, 
 while some have even gone fur- 
 ther, and have censured the style 
 of the Romans as being compara- 
 tively rude and coarse in taste, and 
 their system as being radically vi- 
 cious and inconsistent. Such is the 
 opinion of both Mr. Fergusson and 
 Mr. Freeman; and the latter writer 
 further thinks, that " if the mad 
 desire of imitating Greece had ne- 
 ver taken possession of the Roman 
 mind," Rome might, by adhering to 
 her own previous mode of construc- 
 tion with the arch and vault alone, 
 have ultimately wrought out a well- 
 organized style, greatly superior 
 to what she actually did produce, 
 and which he pronounces to be, 
 although not without its merits, 
 " absurd and inconsistent to the 
 last degree." This almost unqua- 
 lified depreciation errs, perhaps, 
 nearly as much as exaggerated and 
 implicit admiration had done pre- 
 viously. 
 
 Nothing, indeed, is to be said in 
 favour of the treatment of the two 
 Greek orders by the Romans ; for, 
 strange to say, so far from the 
 Doric acquiring greater energy, or 
 the Ionic greater luxuriance, at 
 their hands, the one was emascu- 
 lated, the other impoverished, and 
 both of them rendered insipid and 
 characterless. On the other hand, 
 it is to the Romans that we are in- 
 debted for almost all that we know 
 of the Corinthian order as a style; 
 and it might, with far greater pro- 
 priety, be termed the Roman than 
 the Corinthian one ; for they not 
 only greatly affected it and stamped 
 it as their own, but frequently 
 treated it with singular gusto. 
 
 As to Roman architecture gene- 
 rally, it possesses mechanical ad- 
 vantages and powers of construc- 
 tion unknown to that of the Greeks, 
 and, owing to the adoption of cir- 
 cular and other curved forms of 
 plan, possesses also a degree of va- 
 riety and piquancy, if not of highly 
 refined beauty, that we miss in the 
 
ROM 
 
 ROMAN SCHOOL. 
 
 ROM 
 
 other more polished and correct 
 style. Faulty as the interior of the 
 Pantheon is, in regard to many 
 points of design, Greece could ne- 
 ver show anything similar, much 
 less equal to it. The exterior, too, 
 of the same edifice may be quoted 
 as affording an instance of a correct 
 application of a columnar order not 
 introduced as mere decoration be- 
 tween arches, but applied as a 
 portico both for actual use and for 
 the sake of the general effect. If 
 it be a mixed system, that of the 
 Romans possesses this advantage : 
 viz. it allows either arcading or 
 colonnading to be employed as may 
 best accord with circumstances, 
 whether in different buildings or 
 in different parts of one and the 
 same edifice. 
 
 Perfect congruity and simplicity 
 are not the only valuable qualities 
 in architecture ; for there is also a 
 merit and a charm in complexity, 
 when diverse, if not contradictory, 
 elements of construction and de- 
 sign are combined into an harmo- 
 nious whole ; and the Romans ap- 
 pear to have been far more studious 
 of impressiveness of ensemble than 
 of purity of form and elegance of 
 detail. Besides a degree of vastness 
 never aimed at by the Greeks, 
 sumptuousness and picturesque- 
 ness may be said to have been the 
 predominant characteristics of their 
 buildings, at least, of all their 
 principal monuments. 
 
 Surely, then, we are at liberty to 
 admire Roman architecture for its 
 better qualities, without either be- 
 ing blind to its faults and defects, 
 or imitating them, as if they were 
 inseparable from its merits. Cer- 
 tain it is, that in all matters of de- 
 sign and decoration, modern taste 
 inclines infinitely more to that of 
 the Romans than of the Greeks. 
 Hardly, too, can we dispense with 
 Roman taste and Roman ideas, un- 
 less we can dispense with the Ita- 
 lian style also : yet the latter style, 
 or one founded upon it, must con- 
 
 tinue to be employed for our secu- 
 lar buildings, both public and pri- 
 vate, mediaeval architecture being 
 wholly out of the question for 
 buildings generally at the present 
 day. 
 
 Roman School (The}. It has been 
 doubted whether the Roman 
 school possesses the right to that 
 appellation. Because the schools 
 of Florence, Bologna, and Venice 
 were founded by their respective 
 citizens, and supported through a 
 long course of ages ; while the 
 Roman school could boast only of 
 Giulio Romano and Sacchi, and a 
 few others, natives of Rome. The 
 other artists were from other 
 parts of Italy. As the Univer- 
 sities derive their names from the 
 city where they are established, 
 though the professors may be from 
 other states, so with the schools 
 of painting, the name of the coun- 
 try is always attached in prefer- 
 ence to that of the master. 
 
 The masters of the Roman school 
 are 
 
 Pietro Perugino. 
 Raffaello, b. 1483, d. 1520. 
 Barocci, b. 1528, d. 1612. 
 Caravaggio, b. 1569, d. 1609. 
 Mola di Como. 
 
 Andrea Sacchi, b. 1600, d. 1661. 
 Nicholas Poussin, b. 1594, d. 1665. 
 Salvator Rosa, b. 1615, d. 1673. 
 Claude Lorraine, b. 1600, d. 1682. 
 Gaspar Poussin, b. 1613, d. 1675. 
 
 The characteristic feature of 
 the Roman school consists in a 
 strict imitation of the works of 
 the ancients, not only in sub- 
 limity, but also in elegance and 
 selection. 
 
 PIETRO PERUGINO is the first 
 most eminent name that occurs in 
 the Roman school. His manner is 
 somewhat hard and dry, like that 
 of other painters of his time ; and 
 he occasionally exhibits a poverty 
 in the drapery of his figures. But 
 he atones for these faults by the 
 grace of his heads, particularly in 
 his boys and in his women, which 
 
 393 
 
ROM 
 
 ROMAN SCHOOL. 
 
 ROM 
 
 have an air of elegance ami a 
 charm of colour unknown to his 
 contemporaries. In the Sistine he 
 has a ' St. Peter invested with the 
 Keys,' and at Perugia the ' Mar- 
 riage of the Virgin.' This picture 
 is one of the finest objects that 
 nohle city affords, and may be con- 
 sidered as containing an epitome 
 of the various styles of Pietro. 
 
 It is a remarkable fact that the 
 period of Da Vinci and Buonar- 
 ruoti embraces not only Raffaello, 
 but Correggio, Giorgione, and Ti- 
 tian, and the most celebrated Ve- 
 netian painters ; so that a man 
 might have seen all these illus- 
 trious artists. 
 
 RAFFAELLO, born in Urbino, 
 1483. On settling at Rome, his 
 principal pursuit was the study of 
 the remains of Grecian genius, by 
 which he perfected his knowledge 
 of art. He studied, too, the ancient 
 buildings, and was instructed in 
 architecture for six years by Bra- 
 maute. He lived among the an- 
 cient sculptors, and derived from 
 them not only their contours and 
 drapery and attitudes, but the 
 spirit and principles of the art it- 
 self. He also employed artists to 
 copy the remains of antiquity at 
 Pozzuolo and throughout Italy, 
 and even in Greece. Nor did he 
 derive less assistance from living 
 artists whom he consulted on his 
 compositions. 
 
 As Michelangiolo had before 
 studied the torso of the Belvidere, 
 so Raffaello also formed himself on 
 this and other marbles. 
 
 He was employed nine years on 
 the three chambers in the Vatican. 
 
 Raffaello is placed at the head 
 of his art, not because he excelled 
 all others in every department of 
 painting, but because no other ar- 
 tist has ever possessed the various 
 parts of art united in so high a 
 degree. 
 
 We stand in amaze at the con- 
 tours, grace, precision, diligence, 
 and genius which his drawings ex- 
 
 hibit. In chasteness of design, he 
 was by some placed on a level with 
 the Greeks, though this praise we 
 must consider as extravagant. 
 
 He selected the beautiful from 
 nature, and, as Mariette observes, 
 he copied it with all its imperfec- 
 tions, which he afterwards gradu- 
 ally corrected, as he proceeded 
 with his work. Critics have often 
 wished that his female heads pos- 
 sessed a more dignified character. 
 His children are not so beautiful 
 as those of Titian. The heads of 
 his men are the most perfect. 
 
 As to expression, there is not a 
 movement of the soul, there is not 
 a character of passion known to the 
 ancients and capable of being ex- 
 pressed by art, that he has not 
 caught, expressed, and varied, in a 
 thousand different ways, and al- 
 ways within the bounds of pro- 
 priety. 
 
 In regard to colour, Raffaello 
 must yield to Titian and Correg- 
 gio, although he excelled Michel- 
 angiolo. 
 
 His frescoes may rank with the 
 first works of other schools in that 
 line ; not so his picture in oil. 
 
 In composition, he is at the 
 head of his art. 
 
 GIULIO PIPPI, or GIULIO RO- 
 MANO, was the most distinguished 
 pupil of Raffaello. He resembled his 
 master more in energy than in deli- 
 cacy of style, and was particularly 
 successful in subjects of war and 
 battles. In style of design he emu- 
 lates Michelangiolo, and commands 
 the whole mechanism of the human 
 body. His demonstrations of mo- 
 tion are too violent. He generally 
 painted in fresco, and his vast 
 works at Mantua place him at the 
 head of that school. 
 
 GlANFRANCESCO PfiNNI, of 
 
 Florence, called IL FATTORE, was 
 a principal scholar of Raffaello. Of j 
 his works, his frescoes in Rome j 
 have perished, and few of his oil 
 pictures remain. He is charac- 
 terized by fertility of conception, 
 
ROM 
 
 ROMAN SCHOOL. 
 
 ROM 
 
 grace of execution, and a singular 
 talent for landscape. 
 
 FRANCESCO PRIMATICCIO was 
 a pupil of Giulio. 
 
 GIOVANNI DA UDINE was Raf- 
 faello's principal assistant in the 
 arabesques of the Loggie. 
 
 PERINO DEL VAGA. Vasari con- 
 sidered him the best designer of 
 the Florentine School, after Mi- 
 chelangiolo. 
 
 POLIDORO DA CARAVAGGIO, a la- 
 bourer in the Vatican, distinguished- 
 himself in the imitation of antique 
 bassi-relievi painting in chiaro-os- 
 curo. Nothing of this kind was 
 more perfect in composition, me- 
 chanism, or design. 
 
 BENVENUTO TISIO, called IL 
 GAROFALO,studiedunderRaffaello. 
 Rome, Bologna, and other cities of 
 Italy abound with his pictures 
 from the lives of the Apostles. 
 They are of various merit, and not 
 wholly painted by himself. 
 
 GAUDENZIO FERRARI, assistant 
 of Raffaello in Albano. He never, 
 however, equalled his master in 
 grace, although he had a bolder 
 tone of colour, greater invention, 
 and more vigour of subject. He 
 died in the prime of life. Rome 
 possesses many of his pictures, 
 particularly in fresco, in the 
 churches ; and in the Quirinal Pa- 
 lace is ' Joseph found by his Bre- 
 thren,' which is esteemed a most 
 beautiful piece. There are also 
 many of his pictures to be found 
 in private collections ; and in nis 
 landscapes, in which he excelled, 
 it is doubted whether the figures 
 are by him. 
 
 ANDREA SACCHI was a pupil of 
 Albano. He was the best colourist 
 of the Roman school, and one of 
 the most celebrated in design. 
 Profoundly skilled in the theory of 
 his art, he was slow in execution. 
 His pictures are rare. His compo- 
 sitions do not abound with figures, 
 but every figure appears appro- 
 priate to its place. He seems born 
 for the grand style grave miens, 
 
 majestic attitudes, draperies folded 
 with care and simplicity ; a sober 
 colouring, and a general tone, 
 which gave to all objects a pleasing 
 harmony and a grateful repose to 
 the eye. His picture of ' S. Ro- 
 mualdo surrounded by his Monks' 
 is ranked among the four best 
 compositions in Rome. His ' Tran- 
 site di S. Anna' at S. Carlo a' 
 Catinari, his ' S. Andrea' in the 
 Quirinal, and his ' S. Joseph' at 
 Corpo alle Case, are also beautiful 
 pictures. He was born in the vi- 
 cinity of Rome in 1599, and died 
 in 1661. 
 
 POUSSIN (NICHOLAS). He stu- 
 died the Greek statues, and the 
 remains of antiquity afforded him 
 instruction which he could not ex- 
 pect from masters. From the 
 Meleager of the Vatican (a Mer- 
 cury) he derived his rule of pro- 
 portion. As a model of composi- 
 tion, he attached himself to the 
 * Aldobrandini Marriage ; ' and 
 from that and from basso-relievos 
 he acquired that elegant contrast, 
 that propriety of attitude, and that 
 fear of crowding his picture, for 
 which he was remarkable, being 
 accustomed to say that a half-figure 
 more than requisite was sufficient 
 to destroy the harmony of a whole 
 composition. He remained in Rome 
 twenty-three years. 
 
 Of LANDSCAPE PAINTERS, Sal- 
 vator Rosa, Claude Gellee of Lor- 
 raine, and Gaspar Dughel, called 
 Poussin, appeared under Urban. 
 
 Salvator Rosa and Gaspar Pous- 
 sin resembled each other in de- 
 spatch. Both these artists were 
 accustomed to commence and finish 
 a landscape and decorate it with 
 figures on the same day. 
 
 G. Poussin is accused of not 
 having sufficiently diversified his 
 tints, and of adhering too much to 
 a green hue. 
 
 Maratta supports the art in its 
 decline. 
 
 Roman balance, in mechanics, the 
 steelyard or statera Romana. 
 
 395 
 
ROM 
 
 ROOFS. 
 
 ROO 
 
 Romanesque Architecture, a rftme 
 given to the style of architecture 
 which prevailed after the decline 
 of the Roman empire, from the 
 reign of Constantine till the intro- 
 duction of the pointed arch. 
 
 Roman white is of the purest white 
 colour, but differs from the blanc 
 d'argent only in the warm flesh- 
 colour of the external surface of 
 the large square masses in which it 
 is usually prepared. 
 
 Rood, in surveying, the fourth part of 
 an acre in square measure, or.1,210 
 square yards ; a rod ; a pole ; a mea- 
 sure .of 16 feet, in long measure. 
 
 Rood, or roode, a cross; a crucifix 
 or image of Christ on the cross, 
 placed in a church. The holy 
 rood anciently was elevated at the 
 junction of the nave and choir, 
 and faced the western entrance to 
 a church. 
 
 Rood-loft, a gallery which was gene- 
 rally placed over the chancel screen 
 in parish churches, and was an ad- 
 dition peculiar to the Church of 
 Rome. The rood-loft or gallery 
 had its real support from the tie- 
 beams which connected it with the 
 walls of the building; but in the 
 Decorative construction it appeared 
 to rest on a range of arches or 
 mullions below. Rood-lofts are 
 formed both of stone and wood. 
 
 Rood-tower, or steeple, a tower or 
 steeple at the intersection of the 
 nave and transept of a church. 
 
 Roof, the part above .the miner's 
 head ; that part of the strata lying 
 immediately upon the coal. 
 
 Roofs, or coverings to buildings, are 
 variously formed, both as to mate- 
 rials and construction, although 
 certain essential qualifications are 
 common to all of them. Thus, they 
 are required to effectually exclude 
 the weather, and at the same time 
 impose the least possible weight 
 upon the walls of the buildings 
 over which they are erected ; and 
 another purpose which they should 
 be designed to effect is that of aid- 
 ing the walls in maintaining their 
 
 396 
 
 . position by acting as ties between 
 them at their highest and least 
 stable points. A roof consists main- 
 ly of two parts, viz. the framing 
 or trussing, and the covering, the 
 width of most buildings being too 
 great to be spanned with any prac- 
 ticable covering without the sup- 
 port of framing beneath it. In 
 order to avoid unnecessarily load- 
 ing the walls, the entire roof should 
 be constructed as light as possible 
 consistent with safety and durabi- 
 lity, and its several parts so dis- 
 posed that the weight shall fall 
 vertically only upon the walls, and 
 have no tendency to force them 
 asunder. In this respect, there- 
 fore, the framing of a roof is re- 
 quired to act entirely together as 
 the supporter of the covering, and 
 cannot be properly designed to act 
 laterally against the walls as abut- 
 ments. Provided this condition is 
 secured, roofs may be formed so as 
 to preserve a level upper surface, 
 or a ridged surface, the adoption 
 of the form depending upon the 
 occasion which may or may not 
 exist for using the exterior of the 
 roof as a place of resort for persons 
 or otherwise. Thus, in the East, 
 and in warm climates, roofs are 
 commonly made flat on the top ; 
 while in temperate regions, ex- 
 posed to rains, they are usually 
 ridged, the surface being unavail- 
 able, and the escape of water faci- 
 litated by this form. 
 
 Flat roofs are generally composed 
 of timber framing, and covered 
 with stone in large slabs, or with 
 artificial cements, or with concrete 
 moulded in rectangular blocks. 
 The timber framing in these roofs 
 consists of main beams which span 
 the roof from wall to wall in one 
 direction, and of rafters of smaller 
 scantling laid transversely to the 
 beams, and notched down upon 
 them ; the distance between the 
 rafters being determined by the 
 size of the covering blocks or 
 slabs. 
 
ROO 
 
 ROOM AND SPACE. 
 
 ROO 
 
 Ridged roofs are composed of 
 framings of wood, malleable iron, 
 or cast-iron, and coverings of tiles 
 of burnt clay in various forms, of 
 slate, of iron in rolled sheets or 
 cast plates, of copper or lead in 
 sheets. Each frame of the roof is 
 termed a truss, and consists of se- 
 veral members, according to the 
 width of the truss or span of the 
 roof. The principal of these mem- 
 bers, in a wooden truss, are the 
 tie-beam, which equals in length 
 the span of the roof, and is laid 
 horizontally across the building, 
 resting at each end upon a wall- 
 plate of timber, a cast-iron shoe, or 
 a stone template ; the principal 
 rafters, which are two timbers of 
 equal length, framed into the ends 
 of the tie-beam, and meeting, in 
 the manner of the legs of an isos- 
 celes triangle, in a point equidis- 
 tant from the ends of the tie-beam 
 and at some height above its cen- 
 tral point. The apex of the tri- 
 angle or ridge of the roof is sup- 
 ported by a vertical post, called the 
 king-post, properly framed and se- 
 cured to the heads of the rafters 
 and to the tie-beam. The two tri- 
 angular spaces thus formed be- 
 tween the rafters, tie-beam, and 
 king-post are filled in with other 
 members, according to the size of 
 the truss, and adapted to assist the 
 rafters in bearing the weight of the 
 covering, and to connect each 
 rafter with the half of the tie-leam 
 below it in a firm and substantial 
 manner. In roofs of small span, 
 these additional members are sim- 
 ply two struts fixed in a diagonal 
 position from the bottom of the 
 king-post on either side to the 
 middle of the length of each rafter. 
 In larger roofs the requisite strength 
 is attained, and a space saved in 
 the roof (available as a dormitory 
 or store-room), by introducing two 
 vertical .posts, termed queen-posts, 
 leaving a space in the centre of the 
 roof between them, these queen- 
 posts being secured by straps below 
 
 397 
 
 to the tie-beam, and bearing the 
 rafters above. A horizontal beam 
 connects the heads of the queen- 
 posts, and is termed a collar- 
 beam, the centre of which is se- 
 cured to a king-post, which sup- 
 ports the heads of the principal 
 rafters and the ridge of the roof. 
 Diagonal struts are framed in be- 
 tween the rafters and the king- 
 posts and queen-posts, and thus 
 complete the truss. The trusses 
 are fixed at intervals, from 7 to 1 2 
 feet, apart, throughout the length 
 of the roof, and upon their princi- 
 pal rafters longitudinal timbers, 
 called purlins, are notched down, 
 and carry the common rafters, 
 which are of minor scantling, fixed 
 parallel to the principal rafters, at 
 small distances apart. According 
 to the kind of covering to be used, 
 thin strips of wood, called battens, 
 are secured to the common rafters, 
 and upon these the slates, tiles, etc., 
 are secured with pegs, or copper 
 nails. 
 
 Iron roofs, which are much su- 
 perior to those of timber, especially 
 for large spans, from their light- 
 ness and resistance to fire, are 
 composed of the same essential 
 members as those here described, 
 malleable rods or flat bars being 
 substituted for the tie-beams and 
 king-posts, and the rafters and 
 struts made of sufficient stiffness 
 with bars of malleable L or T-iron, 
 or with cast-iron of suitable form 
 and section. In these roofs all the 
 meeting-points of the several parts 
 of each truss or principal are pro- 
 vided with cast-iron shoes, sockets, 
 and connecting-plates, into which 
 the ends of the rafters, struts, and 
 rods are secured with screwed bolts 
 and nuts, or gibs and keys. 
 Room and space, the distance from 
 the joint or moulding edge of one 
 floor timber to the other, which, in 
 all ships that have ports, should be 
 so disposed that the scantling of 
 the timber of each side of the port, 
 and the breadth of the port fore 
 
ROO 
 
 ROPE MACHINERY. 
 
 ROY 
 
 and aft (the openings between tfie 
 timbers of the frames, if any, in- 
 cluded), be answerable. 
 Root, in arithmetic and algebra, de- 
 notes a quantity which, being mul- 
 tiplied by itself, produces some 
 higher power. 
 
 Rope, twisted hemp or wire, used in 
 all kinds of buildings, for the ma- 
 nagement and control of building, 
 for the construction of bridges, 
 and on board ship ; it is a species 
 of tackle inseparable from the arts. 
 Rope machinery. The simple and 
 beautiful contrivance employed in 
 the dockyards for this most useful 
 material, is contrived by machinery 
 for the spinning of hemp into 
 yarns, and the final preparation of 
 the same into ropes and cables for 
 the navy. The process first em- 
 ployed is separating the fibres from 
 the hemp, and disposing them as 
 nearly as possible into parallel jux- 
 taposition ; then the conversion of 
 these bundles of parallel fibres into 
 a flattened ribbon-like form called 
 a sliver, and the spinning of this 
 sliver into a yarn, or simple twist. 
 In a valuable treatise in vol. v. of 
 the 'Papers of the Royal Engi- 
 neers,' will be found illustrative 
 plates of the machinery employed 
 in this operation in Deptford dock- 
 yard, together with an elaborate 
 description. 
 
 Rotary, an office in the Church of 
 Rome made up of five or fifteen 
 tens of beads, each ten beginning 
 with a Pater-noster, to direct them 
 to say so many Ave Marias in 
 honour of the Virgin Mary. 
 Rose Pink is a coarse kind of lake, 
 produced by the dyeing of chalk or 
 whiting with a decoction of Bra- 
 zil wood, etc. It is a pigment 
 much used by paper-stainers and 
 in the commonest distemper paint- 
 ings, etc., but too perishable to 
 merit the attention of artists. 
 Rosetta wood is a good-sized East 
 Indian wood, imported in logs, 9 
 to 14 inches in diameter; it is 
 handsomely veined. The general 
 
 398 
 
 colour is a lively red-orange. The 
 wood is close, hard, and very beau- 
 tiful when first cut, but soon gets 
 darker. 
 
 Rose window, a circular window. 
 
 Rose-wood is produced in the Brazils, 
 the Canary Isles, the East Indies, 
 and Africa. It is imported in very 
 large slabs, or the halves of trees, 
 that average 18 inches wide. The 
 colours of rose-wood are from light 
 hazel to deep purple, or nearly 
 black ; the tints are sometimes 
 abruptly contrasted, at other times 
 striped or nearly uniform. It is 
 very heavy, and most abundantly 
 used for cabinet furniture: large 
 quantities are frequently cut for use 
 in veneers. 
 
 Rostrum, the elevated platform or 
 stage in the forum of ancient 
 Rome, from which the orators 
 addressed the people : a platform 
 in a hall or assembly. 
 
 Rotary motion, the rotation or mo- 
 tion of any body round an axis or 
 centre: the velocity of this motion 
 of bodies is proportional to their 
 distance from such centre. 
 
 Rotunda, in architecture, an appella- 
 tion given to any building that is 
 round both within and without side, 
 whether it be a church, saloon, 
 theatre, etc. The rotunda at Rome, 
 called the Pantheon, and the 
 chapel of the Escurial, the bury- 
 ing place of Spanish royalty, etc., 
 are of this form. 
 
 Rouge. The ' rouge vegetale ' of the 
 French is a species of carmine pre- 
 pared from safflower, of exquisite 
 beauty and great cost. Its prin- 
 cipal uses consist in dyeing silks 
 of rose colours, and in combining 
 with levigated talc to form the 
 paint of the toilette, or cosmetic 
 colours employed by the fair. 
 
 Roughcast, in building, a kind of 
 
 plaster mixed with pebbles, and 
 
 consequently rough on the surface. 
 
 Roundhouse, the uppermost deck in 
 
 a ship abaft, sometimes called the 
 
 poop. 
 
 Royal Blue is a deep-coloured and 
 
RUB 
 
 RUDDER. 
 
 RUS 
 
 beautiful smalt, and is also a vit- 
 reous pigment, principally used in 
 painting on glass and enamelling, 
 in which uses it is very permanent ; 
 but in water and oil its beauty soon 
 decays, as is no uncommon case 
 with other vitrified pigments: it 
 is not in other respects an eligible 
 pigment, being, notwithstanding 
 its beautiful appearance, very in- 
 ferior to other cobalt blues. 
 Rubble, coarse walling constructed of 
 rough stones, small, irregular in 
 size and shape ; a mixture, or the 
 refuse of several kinds of building- 
 stone used for walls exteriorly, or 
 between walls, to fill up. 
 Rubens' Brown. The pigment still in 
 use in the Netherlands under this 
 appellation is an earth of a lighter 
 colour and more ochreous texture 
 than the Vandyke brown of the 
 London shops ; it is also of a 
 warmer or more tawny hue than 
 the latter pigment, and is a beau- 
 tiful and durable brown, which 
 works well both in water and oil, 
 and much resembles the brown 
 used by Teniers. 
 
 Rubric, or Madder Lakes. These pig- 
 ments are of various colours, and 
 are known by the names of rose, 
 rubiate, rose madder, pink madder, 
 and Field's lakes. 
 
 Rudder, the principal matter which 
 guides the ship. The main-piece 
 and the bearding-piece are always 
 oak, and the rest generally fir. The 
 rudder should be bearded from the 
 side of the pintles, and the fore-side 
 made to the form of the pintles ; 
 but when they are bearded to a 
 sharp edge at the middle line, 
 which is the customary way, it 
 reduces the main-piece more than 
 is necessary, which is easily per- 
 ceived in large ships ; for when the 
 rudder is braced over, the beard- 
 ing will not lie close to the stern- 
 post by nearly f of an inch. 
 Rudder irons, or pintles, the irons 
 which are fastened to the rudder 
 in order to hang it up to the stern- 
 post : sometimes there are two of 
 
 them cut short to work in a socket 
 in the brace, which makes the 
 rudder work easier. 
 
 Rudenture, in architecture, the figure 
 of a rope or staff, sometimes plain 
 sometimes carved, with which the 
 third part of the flutings of columns 
 are frequently filled up. 
 
 Ruderation, in building, a term used 
 by Vitruvius for laying of pavement 
 with pebbles. To perform the 
 ruderation it is necessary that the 
 ground be well beaten, to make it 
 firm, and to prevent it from crack- 
 ing ; then a stratum of little stones 
 is laid, to be afterwards bound 
 together with mortar made of lime 
 and sand : if the sand be new, its 
 proportion may be to the lime as 
 three to one ; if dug out of old 
 pavements or from walls, as five to 
 two. 
 
 Running rigging, in navigation, de- 
 notes all that portion of a ship's 
 rigging which passes through the 
 blocks, to dilate, contract, or tra- 
 verse the sails. 
 
 Russet, Rubiate, Madder Brown, or 
 Field's Russet, is, as its names indi- 
 cate, prepared from the rubia tinc- 
 toria, or madder root. It is of a 
 pure, rich, transparent, and deep 
 russet colour, of a true middle hae 
 between orange and purple, not 
 subject to change by the action of 
 light, impure air, time, or mixture 
 of other pigments. It has supplied 
 a great desideratum, and is indis- 
 pensable in water-colour painting, 
 both as a local and auxiliary co- 
 lour, in compounding and pro- 
 ducing with yellow the glowing 
 hues of autumnal foliage, etc., and 
 with blue the beautfful and endless 
 variety of aerial greys. 
 
 Rustication, the general name for 
 that species of masonry in which 
 the several courses of the stones in 
 each course are distinctly marked 
 by sunk joints or grooves, either 
 chamfered or otherwise cut. Rus- 
 tication admits of great variety of 
 treatment, consequently of expres- 
 sion also; for, quite contrary to 
 
 399 
 
 s 2 
 
SAC 
 
 SAFETY-VALVES. 
 
 SAl 
 
 what its name literally imports? it 
 is frequently made to show the 
 very reverse of careless rudeness, 
 namely, studied ornamentation, by 
 means of highly finished moulded 
 joints, etc. ; and even when the 
 faces of the rustics or stones are 
 
 vermiculated, or otherwise made 
 rough, it is left to be seen that it 
 is done purposely or artificially, 
 more especially when the vermicu- 
 lation, etc., is made to show a sort 
 of panel surrounded by a smooth 
 border. 
 
 S. 
 
 SACELLUM, a monumental chapel 
 within a church. 
 
 Sacrarium, a small family chapel in 
 a Roman house; a place for the 
 deposit of anything sacred. 
 
 Sacristy, a room attached to a church, 
 where the sacred vestments and 
 the utensils belonging to the altars 
 were placed ; termed also the sex- 
 try, the vestry, etc. 
 
 Saddle, in ship-building, a piece fitted 
 on the upper end of the lacing. 
 
 Safety-lamp, a wire-gauze lamp, con- 
 structed for the purpose of giving 
 light in mines where fire-damp 
 prevails. 
 
 Safety-plug, in locomotive engines, a 
 bolt having the centre filled with 
 a fusible metal. It is screwed into 
 the top of the fire-box, that the 
 metal may melt out by the in- 
 creased temperature when the 
 water becomes too low, and thus 
 admit the water to put the fire 
 out, and save the tubes and fire- 
 box. When the water is allowed 
 to fall below a proper height, there 
 is great risk of spoiling both the 
 fire-box and tubes by the intense 
 action of the fire. This is called 
 4 burning them;' and tubes sub- 
 jected to such a trial are unfit for 
 use again, as the tenacity of the 
 metal has befen destroyed. 
 
 Safety-valves, in locomotive engines, 
 two valves placed on the boiler for 
 the escape of steam when it ex- 
 ceeds the pressure limited by the 
 load on these valves. One of them 
 is placed beyond the control of the 
 engine-man, and is usually called 
 the lock-up valve. The other is 
 regulated by a lever and spring- 
 balance, at a little lower pressure 
 
 400 
 
 than the lock-up valve. The aper- 
 tures for safety-valves require no 
 nice calculation. It is only neces- 
 sary to have the aperture sufficient 
 to let the steam off from the 
 boiler as fast as it is generated, 
 when the engine is not at work. 
 The safety-valve is loaded some- 
 times by putting a heavy weight 
 upon it, and sometimes by means 
 of a lever with a weight to move 
 along to suit the required pressure. 
 
 Safety-valve lever, in locomotive en- 
 gines, the lever fixed at one end to 
 a stud, and resting on the valve at 
 a short distance from this stud. 
 Its length is proportioned to the 
 area of the valve, so that the spring- 
 balance may indicate accurately the 
 pressure in Ibs. per square inch on 
 the boiler, above the atmosphere. 
 
 Sagging, in ship-building, a term the 
 reverse of hogging, being applied 
 to the hull of a ship when the 
 middle part of her keel and bottom 
 arch downwards. 
 
 Sagitta, in architecture, a name 
 sometimes used for the key-piece 
 of an arch. 
 
 Sailing, plain, in navigation, is that 
 which is performed by means of a 
 plane chart, in which the parallels 
 of latitude and longitude are every- 
 where equal. 
 
 Saint Paul's, Old. The tower of old 
 St. Paul's, which had tall lancet 
 windows, was built in 1221. The 
 work of enlargement and restora- 
 tion proceeded gradually eastward. 
 In the year 1240, the new choir 
 was consecrated (i.e. was begun), 
 for Henry de Lacy and Ralph de 
 Baldoch, who survived to the reign 
 of Edward II., were benefactors to 
 
SAI 
 
 SANDAL WOOD. 
 
 SAN 
 
 the " new work at the east end, 
 which is no way distinguishable 
 from the rest of the choir." This 
 choir was therefore about forty years 
 in building. Taking this work at 
 a medium between the first and 
 last of these dates, we have a per- 
 fect specimen of English archi- 
 tecture in the earlier years of Ed- 
 ward I. Here the false arches of 
 the dado are retained, but instead 
 of the single and slender columns 
 of the former era, they are sus- 
 tained on pillars more massy and 
 slightly clustered, of which the 
 capitals resemble a rose, while the 
 cusped arch is surmounted by a 
 sweep highly pointed ; of these the 
 spandrils are filled with quatre- 
 foils, and a rose appears beneath. 
 The triforia remain nearly the 
 same as in the earlier period, but 
 the windows have lost the side co- 
 lumns, the mullions are angular, 
 and the three lights of those in 
 the north aisles surmounted by 
 rich tracery. (Quar. Rev. of Dr. 
 Milner, 1811.) 
 
 Saints' bell, a small bell used in the 
 Roman Catholic worship, to call 
 attention to the more solemn parts 
 of the service. 
 
 Salt-cellars, in Tudor times, were 
 pieces on which the taste and fancy 
 of goldsmiths were severely exer- 
 cised. These artists were held in 
 high estimation, and ranked with 
 architects and sculptors. Benve- 
 nuto Cellini, in the time of Henry 
 VII., was the greatest designer 
 and chaser, or sculptor in gold 
 and silver, in Europe: he visited 
 England at this period, and.jx- 
 cited much attention. 
 
 Sanctum Sanctorum, or holy of holies, 
 the most sacred part of the temple 
 of Jerusalem, containing the ark of 
 the covenant. 
 
 Sanctuary, the presbytery or eastern 
 part of the choir of a church in 
 which the altar is placed. 
 
 Sand is the term applied to any mi- 
 neral substance in a granular state, 
 where the grain is of an appreci- 
 
 401 
 
 able size, and insoluble in water. 
 It is more particularly denominated 
 from the prevailing substance, as 
 siliceous sand, iron sand, etc. Sand 
 is of general use for the mixing of 
 material in building : river sand is 
 far preferable. 
 
 Sand-boxes, in locomotive engines, 
 boxes filled with sand, usually 
 placed near the driving wheels, 
 with a pipe to guide the sand to 
 the rails, to be used when slipping 
 takes place. 
 
 Sand-stone, a soft porous kind of 
 stone, generally known by the 
 name of free-stone. It is com- 
 posed of small particles of quartz 
 in rounded grains, united by an 
 argillaceous or calcareous cement. 
 
 Sandal wood, a tree having somewhat 
 the appearance of a large myrtle. 
 The wood is extensively employed 
 as a perfume in the funereal cere- 
 monies of the Hindoos. The deeper 
 the colour, which is of a yellow 
 brown, and nearer to the root, 
 the better is the perfume. It is 
 imported in trimmed logs from 3 
 to 8, and rarely 14 inches in dia- 
 meter, and the wood is in general 
 softer than box-wood, and easy to 
 cut; it is used for parts of cabinets, 
 necklaces, ornaments, and fans. 
 
 Sanitary Precautions, for London in 
 its southern district, were discussed 
 nearly half a century since. Ralph 
 Dodds, an eminent engineer of that 
 period, writes, in his exhortation for 
 a better supply of pure water, the 
 following : " I cannot help noticing 
 that part of the south metropolis, 
 St. George's Fields, lies 4 or 5 feet 
 below the flow of high water, and 
 is so badly drained, and I may say, 
 so saturated with filthy water, with 
 other deposits of every species of 
 dirt and filth from the City and 
 Southwark, that it must be the 
 first place to invite pestilence, 
 should it ever be generated in this 
 part of the country. I hope this 
 will meet the eye of those who 
 wait only for information to im- 
 prove its situation." 
 
SAP 
 
 SAPPHIRE. 
 
 SAW 
 
 Sapan wood or buckum wood, \& a 
 middle-sized tree, indigenous to 
 Siam, Pegu, etc. : for purposes of 
 dyeing it is inferior. 
 
 Sap-green, or Verde Vessie, is a vege- 
 table pigment prepared from the 
 juice of the berries of the buck- 
 thorn, the green leaves of the wood, 
 the blue flowers of the iris, etc. : 
 it is usually preserved in bladders, 
 and is thence sometimes called 
 bladder green ; when good, it is of 
 a dark colour and glossy fracture, 
 extremely transparent, and of a 
 fine natural green colour. Though 
 much employed as a water colour 
 without gum, which it contains 
 naturally, it is a very imperfect 
 pigment, disposed to attract the 
 moisture of the atmosphere and to 
 mildew ; and having little dura- 
 bility in water-colour painting, and 
 Jess in oil, it is not eligible in 
 the one, and totally useless in the 
 other. 
 
 Sapphire, a pellucid gem, which in its 
 finest state is extremely beautiful 
 and valuable, and inferior only to 
 the diamond in lustre, hardness, 
 and value. Its proper colour is 
 pure blue ; in the finest specimens 
 it is of the deepest azure, and in 
 others it varies into paleness, in 
 sl.ades of all degrees between that 
 of a pure crystal brightness and 
 water without the least tinge of 
 colour, but with a lustre much su- 
 perior to the crystal. The gem 
 known to us by this name differs 
 greatly from the sapphires of the 
 ancients, which was only a semi- 
 opaque stone of a deep blue, veined 
 with white, and spotted with small 
 gold -coloured spangles in the form 
 of stars. 
 
 Saracenic Architecture is a species of 
 architecture derived by the Euro- 
 peans from the Arabs, or Saracens, 
 during the crusades. 
 
 Sarcophagus, a stone coffin or grave 
 in which the ancients laid those 
 they had not a mind to burn. 
 
 Sash, a chequered frame for holding 
 the squares of glass in windows, 
 
 and so formed as to be let up and 
 down by means of pulleys inserted, 
 or other contrivances. The ordi- 
 nary sashes are either single or 
 double hung. 
 
 Sassafras wood is a species of laurel, 
 and the root is used in medicine : 
 it measures from 4 to 12 inches in 
 diameter. It is sometimes used 
 for cabinet-work and turnery. 
 
 Satin-wood. The best variety is the 
 West Indian, imported from St. 
 Domingo both in square logs and 
 planks, from 9 to 20 inches wide. 
 The next in quality is the East 
 Indian, logs from 9 to 30 inches 
 diameter. The wood is close, not 
 so hard as box-wood, but some- 
 what like it in colour, or rather 
 more orange j some pieces are very 
 beautifully mottled and curled. It 
 is much used for internal decora- 
 tions and furniture. It is also used 
 for many other purposes for its 
 light and agreeable tone. 
 
 Saucers, small deep dishes, for sauces, 
 etc., and also used as stands for 
 vases, and other vessels filled with 
 wines, to prevent the liquor being 
 spilt upon the table. In the reign 
 of Elizabeth, dishes and platters, 
 which before her time were quite 
 flat, began to assume their present 
 form . 
 
 Saul, or Sal, an East Indian timber- 
 tree. This wood is in very general 
 use in India for beams, rafters, and 
 various building purposes ; is close- 
 grained and heavy, of a light brown 
 colour, not so durable, but stronger 
 than teak, and is one of the best 
 timber trees of India. 
 
 Senders Blue (a name corrupted from 
 cendres-lleu}, the original deno- 
 mination probably of ultramarine 
 ashes, is of two kinds, the natural 
 and the artificial. The artificial is 
 a verditer, prepared by lime or an 
 alkali, from nitrate or sulphate of 
 copper. The natural is a blue 
 mineral, found near copper mines, 
 and is the same as mountain-blue. 
 
 Saw, a toothed instrument which 
 serves to cut into pieces several i 
 
SAW 
 
 SAW MILLS. 
 
 SAX 
 
 solid matters, as wood, stone, 
 ivory, etc. The best saws are of 
 tempered steel, ground bright and 
 smooth ; those of iron are hammer- 
 hardened : hence the first, besides 
 their being stiffer, are likewise 
 found smoother than the last. 
 They are known to be well ham- 
 mered by the stiff bending of the 
 blade, and to be well and evenly 
 ground by their bending equally in 
 a bow. The edge in which are the 
 teeth is always thinner than the 
 back, because the back is to follow 
 the edge. The teeth are cut and 
 sharpened with a triangular file, the 
 blade of the saw being first fixed 
 in a whetting-block. 
 
 Saw file, a triangular file for sharp- 
 ening a saw. 
 
 Saw Mills. The very ingenious ma- 
 chinery constructed by the late 
 Mr. Henry Maudslay is employed 
 in the dockyards to saw timber, find 
 for cutting deals and the several 
 kinds of timber used in the navy 
 and in public works, into the 
 several scantlings, sizes, forms, or 
 shapes. In vol. vi. of the ' Papers 
 of the Royal Engineers ' will be 
 found a most ample statement of 
 the processes for sawing, and cut- 
 ting, and hoisting by steam power, 
 in Chatham dock, together with 
 engravings illustrative of every 
 operation in these works. 
 
 Saxon Style of Architecture. This 
 is easily recognized by its massive 
 columns and semicircular arches, 
 which usually spring from capitals 
 without the intervention of the en- 
 tablature. In the first Saxon build- 
 ings, the mouldings were extremely 
 simple, the greater part consisting 
 of fillets and plat-bands, at right 
 angles to each other, and to the 
 general surface. The archivolts 
 and imposts were similar to those 
 found in Roman edifices. The 
 general plans and disposition of 
 the latter Saxon churches were as 
 follow : the chief entrance was at 
 the west end into the nave, at the 
 upper end of which was a cross, 
 
 403 
 
 with the arms of it extending north 
 and south ; the east end, contain- 
 ing the choir, terminated in a se- 
 micircular form. A tower was 
 erected over the centre of the 
 cross, and to contain the bells an- 
 other was frequently added, and 
 sometimes two. The large churches 
 contained a nave and two side aisles, 
 one on each side of the nave, 
 and were divided into three tiers 
 or stories, the lower consisting of 
 a range of arcades on each side, 
 the middle a range of galleries 
 between the roof and vaulting of 
 the aisles, and the uppermost a 
 range of windows. The pillars 
 were either square, polygonal, or 
 circular. Such was the thickness 
 of the walls and pillars, that but- 
 tresses were not necessary, neither 
 were they in use. The apertures 
 were splayed from the mullions on 
 both sides. The dressings are ge- 
 nerally placed on the sides of the 
 splayed jambs and heads of the 
 arches, and but seldom against the 
 face of the walls ; and when this 
 is the case, the projectures are not 
 very prominent. The dressings of 
 the jambs frequently consist of one 
 or several engaged columns upon 
 each side. The imposts, parti- 
 cularly those of the windows, have 
 frequently the appearance of being 
 a part of the wall itself. The doors 
 in general were formed in deep re- 
 cession, and a series of equidistant 
 engaged columns placed upon each 
 jamb, and were such, that two 
 horizontal straight lines would pass 
 through the axis of each series, 
 and would, if produced, terminate 
 in a point. Each column is at- 
 tached to a recess formed by two 
 planes, constituting an interior 
 right angle. The angle at the 
 meeting of every two of these re- 
 cesses formed an exterior right 
 angle, which was sometimes ob- 
 tunded, and frequently hollowed. 
 The archivolts, resting on the ca- 
 pitals of the columns, are formed 
 on the soffit shelving, like the 
 
SCA 
 
 SCOLA. 
 
 SCH 
 
 jambs below. The ornaments 'of 
 columns and mouldings are of very 
 simple forms. The rudely sculp- 
 tured figures, which often occur in 
 door cases, when the head of the 
 door itself is square, indicates a 
 Roman original, and are mostly 
 referable to an era immediately 
 preceding the Conquest. 
 
 Scabellum, in ancient architecture, a 
 kind of pedestal, commonly ter- 
 minating in a sort of sheath or 
 scabbard, used to support busts, etc. 
 
 Scagliola, in the arts, a composition, 
 an imitation of marble, laid on 
 brick in the manner of stucco, and 
 worked off with iron tools. 
 
 Scala, a ladder, a staircase, from Scala 
 Santa, a building at Rome, erected 
 from the designs of Fontana, with 
 three flights of stairs. The build- 
 ing is so called because the middle 
 flight consists of twenty-eight steps, 
 said to have been passed over by 
 our Saviour in his progress to the 
 house of Pilate. They were sent 
 from Jerusalem to Rome by St. 
 Helena, and are objects of reve- 
 rence to Roman Catholic pilgrims. 
 
 Scale, in painting, a figure subdivided 
 by lines like a ladder, which is used 
 to measure proportions between 
 pictures and the things repre- 
 sented. 
 
 Scamillus, a small plinth below the 
 bases of Ionic and Corinthian co- 
 lumns. 
 
 Scantling, the transverse dimensions 
 of a piece of timber in breadth and 
 thickness. 
 
 Scantling, is also the name of a piece 
 of timber, as of quartering for a 
 partition, or the rafters, purlin, or 
 pole-plate of a roof. All quartering 
 under five inches is termed scant- 
 ling. 
 
 Scantling, in masonry, the size of 
 the stones in length, breadth, and 
 thickness. 
 
 Scapple: to scapple a stone is to re- 
 duce it to a straight surface with- 
 out working it smooth. 
 
 Scarcement, a plain flat set-off in a 
 wall. 
 
 404 
 
 Scapus, in architecture, the shaft of 
 a column. In botany, a flower- 
 stalk springing straight from the 
 root, as in the primrose, snow- 
 drop, etc. 
 
 Scarf, to lap the ends of plank or 
 timber one over the other, to ap- 
 pear as one solid piece, as keel- 
 pieces, clamps, etc. 
 
 Scarfed, in carpentry, signifies pieced 
 or joined, being a particular method 
 of uniting two pieces of timber by 
 their extremities. 
 
 Scarfing, the junction of two pieces 
 of timber by being bolted or nailed 
 transversely together, so that the 
 two appear as one. 
 
 Scarlet Lake is prepared in form of 
 drops from cochineal, and is of a 
 beautiful transparent red colour 
 and excellent body, working well 
 both in water and oil, though, like 
 other lakes, it dries slowly. Strong 
 light discolours and destroys it, 
 both in water and oil ; and its tints 
 with white lead, and its combi- 
 nations with other pigments, are 
 not permanent: yet when well 
 prepared and judiciously used in 
 sufficient body, and kept from 
 strong light, it has been known 
 to last many years ; but it ought 
 never to be employed in glazing, 
 nor at all in peformances that aim 
 at high reputation and durability. 
 
 Scarp, in heraldry, signifies the scarf 
 worn by military commanders. 
 
 Scena, the permanent architectural 
 front which faced the audience 
 part of a Roman theatre : it some- 
 times consisted of three several 
 ranges of columns one above an- 
 other. 
 
 Scenoyraphy, in perspective, the re- 
 presentation of a body on a per- 
 spective plane ; a description there- 
 of in all its dimensions, such as it 
 appears to the eye. 
 
 Schola, the margin or platform sur- 
 rounding a bath. It was occupied 
 by those who waited until the bath 
 was cleared. The schola was also 
 a portico corresponding to the 
 exedra of the Greek palaestra, and 
 
SCH 
 
 SCREW. 
 
 SCR 
 
 was intended for the accommoda- 
 tion of the learned, who were 
 accustomed to assemble and con- 
 verse there. 
 
 Schools of Painting. A school in the 
 fine arts denominates a class of 
 artists who have learned their art 
 from a certain master, either by 
 receiving his instruction or by 
 studying his works, and who of 
 consequence discover more or less 
 of his manner from the desire of 
 imitation x or from the habit of 
 adopting his principles. All the 
 painters which Europe has pro- 
 duced since the renovation of the 
 arts are classed under the following 
 Schools: the School of Florence, 
 the School of Rome, the School of 
 Venice, the Lombard School, the 
 French School, the German School, 
 the Flemish School, the Dutch 
 School, the Spanish and the Eng- 
 lish School. 
 
 Schooner, in navigation, a small two- 
 masted vessel whose mainsail and 
 foresail are suspended from gaffs 
 and stretched out below by 
 booms. 
 
 Schweinfurt Blue appears to be the 
 same in substance as Scheele's 
 green, prepared without heat, or 
 treated with an alkali. It is a 
 beautiful colour, liable to the same 
 changes, and is of the same habits 
 as blue verditer, and the above 
 ineligible pigment. 
 
 Sciagraphy, in architecture, the pro- 
 file or section of a building, to 
 show the inside thereof. In astro- 
 nomy, the art of finding the hour 
 of the day or night by the shadow 
 of the sun, moon, or stars. 
 
 Sconce, in manufacture, a pensile 
 candlestick, generally with a mirror 
 to reflect the light. 
 
 Scotia, the hollow moulding in the 
 base of an Ionic column, derived 
 from the Greek, signifying shade, 
 because, from being hollow, part 
 of it is always in shadow. The 
 scotia is likewise a groove or chan- 
 nel cut in the projecting angle of 
 the Doric corona. 
 
 Scovanlode, a lode having no goz- 
 zan on its back or near the sur- 
 face. 
 
 Scraper, a piece of iron used to take 
 out the pulverized matter which 
 remains in a hole when bored 
 previous to blasting. 
 
 Screen, a movable framework to 
 keep off an excess of light, or heat, 
 or cold ; a separation ; a partition. 
 In ecclesiastical architecture, a 
 screen denotes a partition of stone, 
 wood, or metal ; usually so placed 
 in a church as to shut out an aisle 
 from the choir, a private chapel 
 from the transept, the nave from 
 the choir, the high altar from the 
 east end of the buiJding, etc. 
 Some very beautiful examples exist 
 of screens, especially of those se- 
 parating the choir from the nave. 
 That of York is of a magnificent 
 character. ' All Saints' Church,. 
 Maidstone,' a work published in 
 4to, is of an interesting description 
 on this head. In modern archi- 
 tecture, a single open colonnade, ad- 
 mitting a view through it, is called 
 a screen of columns : such was that 
 formerly in front of Carlton House. 
 Grosvenor Bouse has a Doric 
 screen in front of it. 
 
 Screen bulk-head, in ship-building,, 
 that which is under the round- 
 house. 
 
 Screw, a spiral groove or thread 
 winding round a cylinder so as to- 
 cut all the lines drawn on its sur- 
 face parallel to its axis at the same 
 angle. The spiral may be either 
 on the convex or concave surface 
 of the cylinder, and it is called 
 accordingly either the screw or 
 the nut. The screw can hardly be 
 called a simple machine, because 
 it is never used without a lever or 
 which to move it home, and then 
 it becomes an engine of amazing 
 power and utility in pressing to- 
 gether substances that have little 
 cohesion, or in raising to short 
 heights ponderous bodies. The 
 smith, the carpenter, the printer, 
 and the packer, all use screws in 
 
 s3 
 
SCR 
 
 SCREW PROPELLER. 
 
 SCR 
 
 their respective occupations. Bates 
 of wool, cotton, hay, etc., may be 
 compressed by means of a screw 
 into packages, the specific gravity 
 of which shall be much heavier 
 than an equal volume of water. 
 Such packages will then sink in 
 the ocean like a cannon-shot. 
 Moreover, many of our domestic 
 operations are performed by means 
 of presses or screws ; as the mak- 
 ing of sugar, oil, and wine. The 
 screw possesses one great advan- 
 tage over the inclined plane, from 
 which its principal of action may 
 be said to be derived. The great 
 attrition or friction which takes 
 place in the screw is useful 
 by retaining it in any state to 
 which it has once been brought, 
 and continuing the effect after the 
 power is removed. It is thus the 
 cabinet-maker's cramp, the smith's 
 vice, and all those instruments 
 made by mathematical instrument- 
 makers in which screws act, can 
 be employed with certainty. Screws 
 are made with threads of various 
 forms : some have sharp, others 
 square or round threads. 
 Screw-jack, a strong screw for lifting 
 or supporting a heavy weight : it 
 rests, by means of a large nut, 
 upon a hollow base or pedestal, 
 and is raised or lowered by turning 
 the nut. 
 
 Screw. Screw propellers, for naviga- 
 tion, by means of steam power, have 
 now become objects of importance 
 to all nations, more particularly for 
 those who navigate the broad wa- 
 ters : they are especially applicable 
 for vessels of war, the machinery for 
 propulsion being without the reach 
 of shot. Screw propellers, however 
 variously they may be modified, all 
 derive their power of propelling 
 by being placed on an axis which 
 is parallel to the keel, and by hav- 
 ing threads or blades extending 
 from the axis, which form seg- 
 ments of a helix or spiral, so that, 
 by causing the axis to revolve, the 
 threads worm their way through 
 
 406 
 
 the water, much in the same way 
 as a carpenter's screw inserts itself 
 into a piece of wood. There is, 
 however, considerable difference 
 between the action of a carpenter's 
 screw and of the screw propeller : 
 the latter, acting upon a fluid, 
 cannot propel the vessel without 
 causing the water to recede, while 
 the carpenter's screw progresses 
 through the wood without any such 
 recession. The law which governs 
 the distance which the water re- 
 cedes is common to the paddle* 
 wheel, and to all bodies moving in 
 the water. The screw propelling is 
 not of recent construction ; we find 
 that so early as 1727, Mr. Duquet 
 invented an hydraulic screw ma- 
 chine, which he placed between 
 two boats, connected by transverse 
 bearing, to which the screw was af- 
 fixed. Mr. Paucton, in 1768, pub- 
 lished his ' Theory of the Screw 
 of Archimedes;' other inventions 
 followed, until a recent date, when 
 Mr. George Rennie applied his 
 comprehensive mind to the sub- 
 ject. Sir John Rennie and Mr. 
 George Rennie undertook, when 
 all other engineers declined the 
 order, to construct the engines for 
 the Ship PropellerCompanyformed 
 in 1836, to work out Mr. J. P. 
 Smith's patent for the application 
 of the screw to propel steam ves- 
 sels, by placing it in a space to be 
 left for that purpose, in that part 
 called the 'dead-wood;' that is, 
 the solid wood-work between the 
 stern-post and the keel of the ves- 
 sel. This screw-propeller vessel 
 was at length launched, and the 
 engines, by the Messrs. Rennie, 
 constructed. This vessel, named 
 the ' Archimedes,' of 232 tons and 
 80-horse power, was brought out 
 in 1840; the success was com- 
 plete, and the publicity given to 
 her performances by her spirited 
 owners, who took her round Great 
 Britain and showed her powers in 
 every port, rendered the capa- 
 bilities of the screw no longer a 
 
SCR 
 
 SCREW PROPELLER. 
 
 SCR 
 
 matter of doubt; she was in the 
 first instance fitted with a single- 
 
 threaded screw, as shewn in the 
 accompanying diagram. 
 
 Other patents were subsequently 
 taken out, and many experiments 
 made. In 1838, Mr. Ericsson ob- 
 tained a patent for a propeller con- 
 
 sisting of six blades, a a a a a a, 
 set at equal distances round a cy- 
 linder concentric with the axis b : 
 the blades and arms were segments 
 
 of a screw. The Archimedean screw 
 is a helix, consisting of an inclined 
 plane wound round a cylinder. 
 When such a screw has commu- 
 nicated a retrograde motion to the- 
 water equal to its own recession, 
 
 the further continuance of the 
 thread will not only be useless, 
 but will occasion a friction by its 
 unnecessary surface. Mr. Rennie 
 proposed to make the screw spiral 
 instead of helical; the thread of 
 
 407 
 
SCR 
 
 SCREW PROPELLER. 
 
 SCR 
 
 his propeller would thus be gene- 
 rated by winding an inclined plane 
 round a logarithmic cone or spire. 
 
 The accompanying diagram will 
 probably best explain the method 
 adopted. 
 
 Various other methods have since 
 been suggested and adopted ; one 
 by Mr. Blaxland. This propeller 
 shaft rests upon a bearing in the 
 false stern-post, which is fitted 
 with a stuffing box. There is an 
 open space on the dead-wood, in 
 which the propeller works, similar 
 to that of the ' Archimedes,' but 
 the propeller rests entirely upon 
 the bearing, instead of having an 
 after-bearing like the screw of that 
 vessel. Captain Carpenter's in- 
 vention was adopted by the Ad- 
 miralty in the pinnace ' Geyser,' 
 commanded by himself. There 
 are in this case two propellers, 
 which are placed in the quarters. 
 They receive motion by means of 
 a rotatory engine, called the disc 
 
 engine. The propellers differ from 
 all others, consisting merely of two 
 flat trapeziums attached by arms 
 to the axis : they are therefore not 
 portions of a screw, though this 
 action is helical. In May, 1843, 
 Mr. BennetWoodcroft was directed 
 by the Lords of the Admiralty to 
 make a screw at his own cost, 
 which they caused to be tried in 
 the ' Rattler.' This screw was 
 made of copper, having four 
 blades ; and it corresponded in 
 every respect with a screw of a 
 uniform pitch, also made of cop- 
 per, in the number of its blades, 
 its diameter, length and pitch, with 
 this exception, that although they 
 each commenced with the same 
 pitch, yet Mr. Woodcroft's screw 
 
 408 
 
SCR 
 
 SCREW PROPELLER. 
 
 SCR 
 
 gradually increased 
 in its pitch through- 
 out, and terminated 
 with an increase of 
 5 percent, additional 
 pitch. The trial of 
 Smith's four-bladed 
 Archimedean or true 
 screw took place in 
 the ' Rattler.' on the 
 18th of March, 1844; 
 and on the 13th of 
 the following month, 
 a trial of Wood- 
 croft's increasing- 
 pitch screw, of four 
 blades, was made 
 with the same vessel. 
 After this trial, Mr. 
 Lloyd, the chief en- 
 gineer of the Admi- 
 ralty, who had been 
 present to superin- 
 tend it, stated to Mr. 
 Woodcroft, who had 
 also been present, 
 that the latter screw 
 was superior to the 
 uniform pitch screw 
 in two important qua- 
 lities ; first, that it 
 propelled the vessel 
 at an equal speed with 
 less power; and, se- 
 condly, that it also 
 propelled the vessel 
 at an equal speed with 
 
 fewer 
 
 revolutions of the screw, which 
 latter quality he considered supe- 
 rior to the former ; but that the 
 difficulty arising from having to 
 drive screws so fast, constituted 
 the greatest obstacle to their in- 
 troduction in the Royal Navy. In- 
 deed, this is the admitted difficulty 
 in the application of the screw as 
 a marine propeller, and the prac- 
 tical difference between it and the 
 paddle-wheel. The great size of 
 latter enables the speed of the 
 engines to accomplish the required 
 velocity of the boat, whereas the 
 small diameter of the screw renders 
 it necessary that it should perform 
 
 409 
 
 many more revolutions than the 
 engine makes strokes. Hence the 
 necessity of introducing some mul- 
 tiplying gearing between the engine 
 and the propeller ; and this multi- 
 plying gear, consisting of cast-iron 
 cog-wheels and pinions, is neces- 
 sarily liable to frequent breakage 
 and damage. The great object to 
 be now achieved in the application 
 of the screw as a marine propeller, 
 is to introduce an intermediate 
 gearing for multiplying the velo- 
 city, which shall not be liable to 
 accident, or to render this gearing 
 altogether unnecessary. Smith's 
 screw, however, with some modifi- 
 cations of his former patent, now 
 
SCR 
 
 SCREW. 
 
 SCR 
 
 diminished to two bladess, is us*d 
 in the navy to some extent, as well 
 as a more recent invention of Mr. 
 Griffiths, whose trials have been 
 generally successful. 
 Screw-cutting Machine. The ma- 
 chinery adapted to this purpose 
 varies in construction according to 
 the notions of the different makers, 
 but the general principle is the 
 same in all, the difference consist- 
 ing in the method of carrying it into 
 effect. The machine is a compound 
 of the ' slide-rest ' and lathe, with 
 a train of wheels to give motion to 
 the former. The metal to be cut 
 into a screw is placed between the 
 centres of the lathe in the usual 
 manner, and the cutting-tool is 
 fixed upon the slide rest, which 
 has its lower slide made parallel to 
 the centre line ; the upper slide is 
 only used for adjusting the cutting- 
 tool. The screw of the lower slide 
 has motion communicated by the 
 train of three or more wheels ; the 
 first, or driving wheel, is fixed 
 on the mandril of the lathe, and 
 last of the train is fixed on the 
 end of the slide-screw ; the other 
 wheels are intermediate wheels. 
 The pitch of the screw to be cut, 
 or distance between the centres 
 of two consecutive threads, is the 
 space traversed by the tool du- 
 ring one revolution of the work, 
 and is regulated by the sizes of the 
 wheels which must therefore be 
 changed for every difference in the 
 pitch. 
 
 The perfection to which screw- 
 cutting has been brought, is mainly 
 attributable to the application of 
 the slide-rest ; and the beautiful 
 and accurate screws, of all sizes, 
 produced by the screw-cutting ma- 
 chine, have contributed in no small 
 degree to the perfection of our ma- 
 chinery in general, and more par- 
 ticularly to that of astronomical 
 instruments. 
 
 There are also other machines, 
 called screwing machines, for 
 screw-cutting, which perform work 
 
 of a much rougher description, such 
 as cutting short screws or bolts, for 
 fastening together the flanges of 
 pipes, etc. The machine consists 
 of a strong iron frame, which 
 carries a mandril somewhat similar 
 to that of a lathe, driven by a band 
 passing over a pulley. The head 
 of the bolt to be screwed is held 
 by a clamp at the projecting end 
 of the mandril, so that it revolves 
 with it as in a lathe, the only dif- 
 ference being, that it is held at 
 one end and free at the other. The 
 dies, or two hardened steel pieces, 
 which together form a nut, with 
 the grooves lengthwise for cutting, 
 are placed in a small frame, across 
 the machine, supported by two 
 guides projecting from the machine 
 frame, one on each side, level and 
 parallel with the bolt. 
 
 When the machine is set in 
 motion, the small cross frame is 
 brought forward, and the end of 
 the revolving bolt is made to enter 
 the dies, which are pressed upon it 
 by set-screws ; and as their cutting 
 edges take effect on the bolt, the 
 frame is carried forward on the 
 guides till it has moved the required 
 length ; it is then brought back by 
 reversing the motion of the ma- 
 chine, and the dies are tightened 
 for another cut : this operation is 
 repeated until the screw is of the 
 required diameter. By fixing a tap, 
 or cutting-screw, to the mandril, 
 in place of the bolt, and holding a 
 nut by the screws in the cross- 
 frame, the machine is made to cut 
 internal screws. 
 
 Scribing, a term applied to the edge 
 of a board when fitted upon any 
 surface. 
 
 Scribing, in joinery, the act of fitting 
 one piece of wood upon another, 
 so that the fibres of both may be 
 perpendicular to each other, and 
 the end cut away across the fibres, 
 so as to fit upon the slide of the other. 
 
 Serin, in mining, a small vein. 
 
 Scroll, a name given to a kind of 
 ornament of general use, which 
 
scu 
 
 SCULPTURE. 
 
 SCU 
 
 resembles a band arranged in un- 
 dulations or convolutions. 
 Sculpture is the art of carving wood 
 or hewing stone into images. It 
 is an art of the most remote anti- 
 quity, having been practised, there 
 is reason to suppose, before the 
 Deluge. To this reason is assigned 
 the expedients by which, in the first 
 stages of society, the images of men 
 have everywhere supplied the place 
 of alphabetical characters. These, 
 it is universally known, have been 
 picture writing, such as that of the 
 Mexicans, which, in the progress 
 of refinement and knowledge, were 
 gradually improved into the hiero- 
 glyphics of the Egyptians and other 
 ancient nations. To make a dis- 
 tinction between carving and sculp- 
 ture, the former belonged exclu- 
 sively to wood and the latter to 
 stone. The latter evinced vast 
 comprehension of mental taste and 
 study of human anatomy as well 
 as that of other animals. In exa- 
 mining the various sculptures of 
 the Egyptians, it is found that a 
 general character prevails through- 
 out their outlines : many valuable 
 specimens remain to attest their 
 greatness in this art. It is to the 
 Greeks that great superiority is due. 
 The art of sculpture probably was 
 influenced by the climate over the 
 human frame, as the violent heats 
 of the torrid zone and the excessive 
 cold of the polar regions are un- 
 favourable to beauty : it is only to 
 the mild climates of the temperate 
 regions that it appears in its most 
 attractive charms. The Romans 
 displayed great talents for statuary; 
 subsequently the Italian masters 
 showed their eminence in the art ; 
 and in our own country the works 
 of Westmacott and Chantrey be- 
 long to the distinguished English 
 School. Carving in wood exists in 
 the fine and most elaborate works 
 of Flemish masters, and those of 
 Gibbons and others of England are 
 of equal talent in this pleasing 
 art. 
 
 411 
 
 The Grecian marbles in the Bri- 
 tish Museum have given so much 
 grace to British art, and to execu- 
 tion in the art generally,that a short 
 description of them, and their con- 
 nection with architecture, will not 
 be unacceptable. 
 
 We learn from Athenian Stuart, 
 that "the Temple of Minerva, 
 called the Parthenon and Heca- 
 tompedon, was built during the 
 administration of Pericles, who em- 
 ployed Callicrates and Ictinus as 
 architects, under Phidias, to whom 
 he committed the direction of all 
 works of elegance and magnifi- 
 cence. It has been celebrated by 
 some of the most eminent writers 
 of antiquity, whose accounts are 
 confirmed and illustrated in the de- 
 scriptions given us by those travel- 
 lers who saw it almost entire in the 
 last century. Even in its present 
 state, the spectator on approaching 
 it will find himself not a little af- 
 fected by so solemn an appearance 
 of ruined grandeur. Accustomed 
 as we were to the ancient and 
 modern magnificence of Rome, and 
 by what we had heard and read, 
 impressed with an advantageous 
 opinion of what we were come to 
 see, we found the image our fa icy 
 had preconceived greatly inferior to 
 the real object. 
 
 "This temple, the most costly 
 and highly finished example of the 
 Doric order, perhaps the largest 
 octastyle temple of antiquity, had 
 the advantage of the great mind 
 of Phidias. It is to Lord Elgin's 
 enterprise and enthusiasm for art 
 that England owes the unique trea- 
 sures deposited in the British Mu- 
 seum. Pausanias remarks, ' On 
 entering the temple called the Par- 
 thenon, all the works in what are 
 termed the pediments (eagles)seem 
 to relate to the birth of Minerva ; 
 those behind represent the contest 
 of Neptune and Minerva concern- 
 ing Attica ; but the statue itself (of 
 the goddess) is formed of ivory and 
 gold.' Pausanias then proceeds to 
 
scu 
 
 SCULPTURE. 
 
 SCU 
 
 a minute description of the chryS- 
 elephantine statue, notices other 
 monuments of art, describes the 
 Erechtheum, and enlarges on the 
 colossal bronze Minerva by Phidias, 
 called Promachus, etc. The beauty 
 of the marble of the mountains 
 surrounding Athens, particularly 
 that of Pentelicus, from which the 
 temple Parthenon was wrought, 
 must have given a great zest to the 
 Athenians in the cultivation of the 
 refinement of architectural design : 
 with more brilliancy, it is almost 
 capable of receiving the high finish 
 of ivory. According to Pliny, Dio- 
 pO3nus and Scyllis, born in Crete 
 about the 50th Olympiad, B.C. 578, 
 were the first sculptors distinguish- 
 ed in working marble, and to them 
 are also attributed the earliest sta- 
 tues of ivory and gold. Of the 
 part Phidias had in the design of 
 the Parthenon temple, and in the 
 production of the sculpture in par- 
 ticular, a diversity of opinion has 
 existed. It has been supposed that 
 the whole of the sculptural deco- 
 rations are the ' undoubted ' pro- 
 ductions of that great artist, thus 
 conveying to them a charm, from 
 the association of that great name, 
 which the unequal execution does 
 not entitle portions of them to re- 
 ceive : others assert that he had 
 nothing to do with the works, but 
 that he may have designed the 
 sculpture. However, the words 
 ' skilful sculptor in marble ' have 
 been applied by Aristotle to Phidias, 
 in opposition to ' statuary,' given 
 by him to Polycletus, whose works 
 were principally in bronze, in order 
 to strengthen the probability of his 
 having executed the marble sculp- 
 ture of the Parthenon. Pliny states 
 Phidias to have been the first who 
 displayed and perfected the toreutic 
 art, or sculpture formed by the 
 combination of metals and other 
 materials. The fertility of genius 
 of this great sculptor, who was 
 equally skilful in every department 
 of his art, was surprising. He was 
 
 at the period of the erection of the 
 Parthenon, engaged in so many and 
 such various monuments belonging 
 to the toreutic art, that his atten- 
 tion must have been occupied by 
 them to so great a degree, that 
 any but a general superintendence 
 of the designs of the temple can 
 scarcely be supposed possible. 
 When executing the Minerva of the 
 Parthenon, he had already comple- 
 ted or was engaged on, besides 
 many other statues and groups in 
 ivory and gold, five other statues 
 of that goddess, probably all of 
 them colossal, of which the Mi- 
 nerva Promachus, in bronze, in 
 the Acropolis, must have been up- 
 wards of 50 feet in height, having 
 been seen from the sea. The pas- 
 sage of Plutarch, describing the 
 artists of the structures of Pericles 
 is, ' Phidias directed and superin- 
 tended all the works of him 
 (Pericles), although they had great 
 architects and artificers ; for Cal- 
 licrates and Ictinus executed the 
 Hecatompedon, or Parthenon.' " 
 Sculpture. Mr. Hailes, in 1825, writes 
 the following. " The introduction 
 of statues of individuals, however 
 eminent and meritorous, into 
 squares and public places, is a no- 
 velty in this our metropolis, which, 
 till of late years, seemed to be re- 
 served for the sovereign and his 
 family. We have, however, two, 
 which, although not contrary to 
 law, at least to any that I know of, 
 are certainly deviations from long- 
 established custom, and a sort of 
 invasion or trespass upon royal 
 prerogative. That of the late 
 Duke of Bedford, the Triptoleraus 
 of his time, in Russell Square, is 
 an erect figure, surrounded by the 
 attributes of husbandry ; and be- 
 neath it are some smaller figures, 
 equally symbolic. The late Bishop 
 
 of E , going with a friend to 
 
 look at this statue, was asked by 
 him what he thought would be the 
 fittest inscription for it. His an- 
 swer was, ' Bovi Optimo Maxi- 
 
 412 
 
scu 
 
 SCULPTURE. 
 
 SEA 
 
 mo.' It seems extraordinary that 
 his Grace, with these emblems of 
 agriculture about him, has not been 
 made to look towards the country 
 instead of the town. But he looks 
 towards Mr. Fox, the Demosthe- 
 nes of our day, in Bedford Square, 
 sitting in a lumpish manner in a 
 sort of curule chair, and habited 
 in a toga, a la Romaine ; his neck 
 is exposed, and the drapery, pass- 
 ing over one of his shoulders 
 across his breast, might very well 
 give occasion, as it did, to one of 
 his old Westminster constituents, 
 to say, ' So, Charley, you are going 
 to be shaved, I see.' These are 
 two very sharp remarks : one from 
 a very highly cultivated man, and 
 a great scholar ; and the other from 
 a very coarse observer, but equally 
 shrewd and comical in their way. 
 They seem to supersede the neces- 
 sity of any other criterion. We 
 are not happy in this branch of 
 the fine arts ; and the only instance 
 in which we can pride ourselves is 
 not of a late date, being the eques- 
 trian statue of Charles the First, 
 by a scholar of John de Bologna, 
 at Charing Cross. Our ill success 
 is perhaps the less to be lamented, 
 as works of this sort, exposed to 
 such an atmosphere as we live in, 
 become in a short time so much 
 defaced as to make it very indiffer- 
 ent whether the workmanship be 
 from the hand of a Glycon or a 
 Bacon. All our monuments of 
 this kind seem to represent our 
 chimney-sweepers, a-foot or on 
 horseback, rather than our kings, 
 princes, and other great men." 
 The late Mr. Nash observed, " that 
 these criticisms are unjust as well 
 as impolitic : by running down the 
 best, we open the door to the worst 
 artists. It is a peculiarly English 
 feeling. If Westmacott's bronzes, 
 which one hardly dares (in the 
 face of criticism) to pronounce un- 
 rivalled in this country, had receiv- 
 ed their due praise, the designer of 
 the Duke of Kent, at the top of 
 
 Portland Place, would never have 
 been suffered to libel the state of 
 English art." 
 
 Scumbling is giving a kind of rough 
 dotted shadow to trees, grass, 
 gravel-walks, etc., in a drawing 
 when it is nearly finished. It is 
 performed with a brush having 
 some dark-brown colour in it, but 
 nearly dry. The hairs of the brush 
 are spread apart, then held in a 
 slanting direction, and swept light- 
 ly over the foreground, or where the 
 shadows are wanting. This is prac- 
 tised by some artists with consi- 
 derable effect. 
 
 Scuppers, holes cut through a ship's 
 side for throwingoff the water from 
 the pump. They should be dis- 
 posed clear of the guns, standards, 
 the ports below, gangways, etc. 
 
 Scutcheon, the shield represented in 
 heraldry. 
 
 Scuttles, holes cut in divers parts of 
 the decks, exclusive of hatchways 
 and ladderways ; likewise holes cut 
 through the ship's side for air. 
 
 Scyricum Marmor, a name given by 
 the ancients sometimes to a white, 
 and sometimes to a yellowish mar- 
 ble ; both used in the public build- 
 ings of the Romans, but seldom in 
 statuary, not being capable of re- 
 ceiving a high polish. 
 
 Sea. The sea covers about three- 
 fourths of the entire surface of the 
 globe. The specific gravity of sea- 
 water is about 1'0277; the water 
 of closed seas into which many 
 rivers fall is lighter, as that of the 
 Black Sea and the Baltic. The 
 water of the Mediterranean is more 
 salt than that of the Atlantic, con- 
 taining about 4-18 per cent., while 
 that of the Baltic contains only 
 1-18 per cent, of salt. There are 
 also other mineral substances in 
 sea-water, as iodine, bromine, mag- 
 nesia, lime, etc., in small quantities. 
 The temperature of the air over 
 the sea has been proved by obser- 
 vation to be more uniform than 
 that of the air over the land ; places 
 near the sea have therefore a 
 
 413 
 
SEA 
 
 more uniform climate than those 
 at a considerable distance from 
 it. 
 
 Seal, a device or an engraved inscrip- 
 tion : also its impression made on 
 wax. Kings, bishops, and prelates 
 were accustomed to use their several 
 devised seals. Cities, towns, cor- 
 porations, companies, institutions, 
 
 SEAL. SEC 
 
 and public bodies, had their seals. 
 Privy or individual seals were also 
 of frequent use, and some very 
 curious seals exhibit much beauty 
 and ingenuity. That represented 
 in the annexed engraving is the 
 seal of Michael Stanhope, who was 
 Vice-Admiral of Suffolk in the time 
 of Queen Elizabeth. 
 
 Seam, in mining, a horse-load. 
 
 Seams,the opening between the planks 
 when wrought. 
 
 Secant, a true line that cuts another 
 or divides it into two parts. 
 
 Section, a vertical plan of the interior 
 of a building, showing it as it 
 would appear upon an upright plane 
 cutting through it. Though rarely 
 shown, sections are almost as in- 
 dispensable as plans ; like which 
 they show the thicknesses of the 
 walls, and, in addition, those of 
 the ceilings and floors; and also 
 
 414 
 
 heights, both of the rooms them- 
 selves, and of doors and windows ; 
 moreover, the forms of the ceil- 
 ings, whether flat, or coved, or 
 vaulted. In one respect, too, a 
 section partakes of the nature of an 
 elevation, the plane parallel to the 
 line of section being an elevation of 
 the interior, or rather consisting of 
 as many elevations as there are se- 
 parate rooms or divisions. Sections 
 maybe described as either furnish- 
 ed or unfurnished : the latter show 
 only construction and the strictly 
 
SEC 
 
 SEPULCHRE. 
 
 SEP 
 
 architectural parts ; wherefore, if 
 the side of a room happens to be 
 quite plain, without door, chimney- 
 piece, or other feature, that side or 
 space will be a blank, or little better. 
 Furnished sections, on the contrary, 
 exhibit, besides what strictly be- 
 longs to the architecture and its 
 decoration, mirrors, pictures, sta- 
 tues, furniture, draperies, and all 
 other accessories. The number of 
 sections required depends upon the 
 nature of the plan, and what may 
 be worth showing. If the design 
 be worthy of it, there should be as 
 many sections as will suffice to 
 show every side of every principal 
 apartment ; though it may not be 
 necessary to repeat the entire sec- 
 tion through every floor. Sections 
 are the delicia of architectural il- 
 lustration. 
 
 Sector, in geometry, an instrument of 
 wood or metal, with a joint and 
 sometimes a piece to turn out and 
 make a true square, with lines of 
 sines, tangents, secants, equal parts, 
 rhombs, polygons, hours, latitudes, 
 etc. 
 
 Sedilia, a name for a seat : the term 
 is applied to the seats for the offi- 
 ciating priests, inserted (and some 
 ornamented) in the south wall of 
 a church. 
 
 Segment of a circle, a part of a circle 
 bounded by an arc and its chord, 
 and either greater or less than a 
 semicircle. 
 
 Segment of a sphere, any part of a 
 sphere cut off by a plane, the ec- 
 tion of which, with the sphere, is 
 always a circle. 
 
 Sella (Latin), the general term for a 
 seat or a chair of any description. 
 Sella Curulis, a chair of state. 
 
 Semaphore, in mechanics, a name 
 given by the French to the tele- 
 graph, and latterly adopted in 
 England to signify any machine to 
 communicate intelligence by signs 
 or signals. 
 
 Semicircle, half a circle, or the area 
 comprehended between a diameter 
 and the semi-circumference. 
 
 Semi-ordinate, in conic sections, a 
 line drawn at right angles to and 
 bisected by the axis, and reaching 
 from one side of the section to the 
 other. 
 
 Sepia, Seppia, or JEthiops-mineral. 
 This pigment is named after the 
 sepia or cuttle, which is called also 
 the ink -fish, from its affording a 
 dark liquid, which was used as an 
 ink and pigment by the ancients. 
 From this liquid our pigment sepia, 
 which is brought principally from 
 the Adriatic, may be obtained from 
 the fish on our own coasts; and 
 it is supposed that it enters into 
 the composition of the Indian 
 ink of the Chinese. Sepia is of a 
 powerful, dusky-brown colour, of a 
 fine texture : it works admirably in 
 water, combines cordially in other 
 pigments, and is very permanent. 
 It is much used as a water-colour, 
 and in making drawings in the 
 manner of bistre and Indian ink, 
 but it is not used in oil, in which it 
 dries very reluctantly. 
 
 Septuagint, the Greek version of the 
 books of the Old Testament, so 
 called because the translation is 
 supposed to have been effected by 
 seventy-two Jews, who are usually 
 called the seventy interpreters. 
 
 Sepulchre, a grave, tomb, or place of 
 interment. Extreme attention to 
 the sepulture of deceased friends 
 characterized nations from remote 
 antiquity, and to be deprived of 
 it was accounted a very degrading 
 circumstance. The Romans were 
 prohibited by a law from burying 
 their dead within the city ; and it 
 was a field that the father of the 
 Jews purchased for the sepulture 
 of his wife. " Hear us, my lord : 
 in the choice of our sepulchres 
 bury thy dead ; none of us shall 
 withhold from thee his sepulchre, 
 but that thou mayest bury thy 
 dead." Gen. xxiii. 6. The ancient 
 tombs of the East are remarkable 
 for their durability, and, in some 
 instances, their beauty : they are 
 monuments on which the lapse of 
 
 415 
 
SER 
 
 SEWERS. 
 
 SEW 
 
 ages effects no change ; in many 
 instances hewn in the solid rock, 
 they are calculated for duration 
 equal to that of the hills in which 
 they have been excavated. In a 
 garden, hewn out of a rock, was 
 the sepulchre of Jesus. 
 
 As an instance of a style of 
 modern sepulture, which is rapidly 
 extending, may be mentioned the 
 Cemetery of Pere la Chaise, at Pa- 
 ris, which comprehends above 150 
 acres, thickly studded with chapels, 
 tombs, and monuments, beautified 
 with winding walks, curtained with 
 lofty shady trees, and adorned with 
 plants and evergreens. It contains 
 nearly 16,000 mausolea built of 
 the finest granite, sandstone, and 
 polished Carrara marble, the ex- 
 pense of which has been estimated 
 at about 120,000,000 francs, or 
 5,000,000 sterling. 
 
 Serges, the great wax candles burnt 
 before the altars in Roman Catholic 
 churches. 
 
 Serpentine, the ophites, or serpent- 
 stone of the ancients. Mona mar- 
 ble is an example of serpentine, 
 and the Lizard Point, Cornwall, is 
 a mass of it. 
 
 Serving, in navigation, encircling a 
 rope with line or spun-yarn, to 
 prevent its being chafed. 
 
 Set-off, or Offset, the part of a wall, 
 etc., which is exposed horizontally 
 when the portion above it is re- 
 duced in thickness. 
 
 Severey, a bay or compartment of a 
 vaulted ceiling. 
 
 Sewers are subterranean passages or 
 channels for the conveyance of 
 waste waters and other matters 
 from towns and buildings. In 
 order that a sewer shall act with 
 efficiency and promote the rapid 
 discharge of the matters committed 
 to it, it is necessary that it be con- 
 structed thoroughly impermeable 
 throughout its entire length, that 
 its interior surface be even and 
 smooth, and present no impedi- 
 ments to the. sewage, and that its 
 vertical declination be sufficient to 
 
 41 A 
 
 prevent any suspension of the cur- 
 rent. The sectional area of the 
 sewer should be amply sufficient to 
 contain the entire volume of the 
 sewage, and its form such as will 
 best secure its action with the 
 minimum contents. The form of 
 a sewer should be adapted to resist 
 the utmost pressure to which it 
 may be exposed externally from 
 the surrounding materials in which 
 it is constructed ; and ready access 
 should be afforded at intervals for 
 examining its condition from time 
 to time, and detecting and re- 
 moving any obstruction which may 
 possibly occur to the immediate 
 passage of the sewage. Hence rec- 
 tangular forms are utterly inap- 
 plicable for these works, the section 
 of which should be entirely curvi- 
 linear; and theory and experience 
 have concurred in appointing a 
 sectional form, similar to that of 
 the egg, as best fulfilling the con- 
 ditions of strength to resist exter- 
 nal pressure, and (the smaller curve 
 being placed downwards) to pro- 
 duce the most activity in the cur- 
 rent when the quantity of sewage 
 is reduced to the minimum. The 
 simplest and best rule for obtain- 
 ing with circular curves a true egg- 
 shaped or oviform section for sewers 
 is that given in the ' Rudimentary 
 Treatise on the Drainage and Sew- 
 age of Towns and Buildings,' be- 
 longing to the same series with 
 this work, and which is therefore 
 here quoted. 
 
 " Let the greater diameter, or 
 that of the upper part of the sec- 
 tion, equal 1 ; the less diameter, or 
 that of the bed of the sewer, equal 
 5 ; and the entire height of the 
 section equal the sum of these, or 
 1-5. Then strike a semicircle of 1 
 diameter for the head or arch of 
 the section, and 120 of a circle 
 of '5 diameter for the invert ; con- 
 nect the arch and invert with side 
 arcs of 1'5 radius, the centres of 
 these side arcs being on the pro- 
 duced horizontal diameter of the 
 
SEW 
 
 SEWERS. 
 
 SEW 
 
 top arch. These arcs will be truly 
 tangential, both to the arch and 
 invert, and will complete a section 
 well adapted for the practical pur- 
 poses of the sewer, and, being so 
 extremely simple in its construc- 
 tion, peculiarly ready of application 
 by workmen in forming and using 
 templates, and in testing the accu- 
 racy of the work as it proceeds. 
 The proper size or sectional area of 
 sewers is determinable upon the 
 quantity of sewage, and the velocity 
 of its passage, which latter element 
 depends jointly upon the rate of 
 declivity at which the sewer is laid, 
 and the volume of water in motion. 
 The quantity of sewage to be con- 
 veyed from a town is made up 
 chiefly of the bulk of the water 
 supplied to the population, the ex- 
 crementitious matters produced, 
 and the quantity of rain-water 
 falling upon the service. The 
 maximum quantity thus accruing 
 during any given period of time 
 will determine the minimum capa- 
 city of the sewer, calculated in 
 combination with the rate at which 
 the passage can be effected ; while, 
 on the other hand, the minimum 
 quantity thus accruing will limit 
 the proper radius of the invert of 
 the sewer, so that the friction of 
 the water against the surface of the 
 sewer may be reduced in proportion 
 to the total bulk of the sewage. 
 All junctions of one line of sewer 
 with another, and all changes of 
 direction whatever, should be form- 
 ed with curves of the greatest pos- 
 sible radius, experiment having 
 proved that the current is impeded 
 in proportion as the radius of cur- 
 vature is reduced, and that angular 
 junctions are still more mischievous 
 in suspending the proper action of 
 the channel. Thus in a sewer 2 
 feet 6 inches wide, a stream having 
 a velocity of 250 feet per minute 
 suffers a resistance from a rectan- 
 gular change of direction three 
 times that produced with a curve 
 of 20 feet in radius, and double 
 
 417 
 
 that produced with a curve of 5 
 feet radius. The inevitable effect 
 of suspending the motion at these 
 junctions is that the solid particles 
 become deposited, and form a per- 
 manent bar, requiring some extra- 
 ordinary action or force of water to 
 remove it. 
 
 " It is usual to distinguish sewers 
 according to their size and func- 
 tions, as first class, or main sewers; 
 second class, or collateral sewers ; 
 and third class, or branch sewers ; 
 while the smaller channels for con- 
 veying the contributions from in- 
 dividual tenements are termed 
 drains. The same rules will apply 
 equally to all of these as far as their 
 proper objects are concerned, al- 
 though the peculiar construction to 
 be adopted will of course depend to 
 some extent upon the actual size of 
 each channel. For the larger sew- 
 ers, constructions of brickwork are 
 commonly used. These require 
 careful formation, and to be accu- 
 rately jointed, and the interior of 
 the invert at any rate smoothly 
 formed with a hard-drying cement. 
 For smaller channels or drains and 
 branch sewers, whole pipes of 
 glazed stoneware are coming into 
 extended employment, and, if truly 
 formed and carefully laid and joint- 
 ed, these form very superior ducts 
 for the passage of the sewage. By 
 the use of these pipes, the essential 
 qualification of impermeability is 
 better secured than with brick 
 sewers, the repeated joints of which 
 need great labour and care in con- 
 struction, and if formed with infe- 
 rior mortar, soon becomes imper- 
 fect. As necessary appliances to 
 all sewers and drains, efficient traps 
 or apparatus to prevent the escape 
 of the noxious gases engendered 
 within the channels are really in- 
 dispensable, and these are required 
 to be simple in construction and 
 unerring in their action. The en- 
 tire subject of the sewage of towns 
 and buildings is now first receiving 
 the attention due to it as a neces- 
 
SEX 
 
 SHEERS. 
 
 SHE 
 
 sary condition to the public health ; 
 and when this important branch of 
 engineering science shall have been 
 thoroughly investigated by qualified 
 public officers, we may hope for 
 the most useful and salutary prac- 
 tice, based upon correct principles, 
 and for corresponding amendment 
 in all that pertains to the subter- 
 ranean ways of our cities, towns, 
 and dwellings." 
 
 Palladio says, " The great com- 
 mon sewer or the general receiver 
 or sink of all the filth of Rome 
 was near the Senatorian bridge, 
 called S. Marca, a performance of 
 Tarquinius Superbus. Authors tell 
 strange things of its largeness, viz. 
 that a full laden hay-cart could 
 drive through it : upon measuring, 
 I have found it to be 16 feet dia- 
 meter. Into this all other sewers 
 of the city do empty themselves, 
 which is the reason that sturgeons 
 taken between the Senatorian and 
 Sublician bridges are better than 
 others, feeding on the filth coming 
 out of this great sewer." 
 
 Very recently the Legislature 
 have deterrainately taken up the 
 subject of purifying the Thames 
 and of draining London, and placed 
 funds at the disposal of the Metro- 
 politan Board of Works ; so that 
 the task, the great task, is fairly in 
 hand, and likely to proceed satis- 
 factorily and it is to be hoped 
 successfully. 
 
 Sextant, in geometry, the sixth part 
 of a circle; in navigation, etc., an 
 astronomical instrument made like 
 a quadrant, but containing only 
 sixty degrees. 
 
 Shaft, in architecture, the body of a 
 column or pillar ; the part between 
 the capital and base. In medieval 
 architecture the term is applied to 
 small columns clustered round pil- 
 lars, or used in the jambs of doors 
 and windows. 
 
 Shaft, in mill-work, a large axle, in 
 contradistinction to a small one, 
 which is called a spindle : thus we 
 say, ' the shaft of a fly-wheel,' 'the 
 
 418 
 
 spindle of a pinion.' Shafts are 
 said to be lying when they are in 
 a horizontal direction, and vertical 
 when they are upright. 
 
 Shaft, in mining, a sinking or pit, 
 either in the lode or through the 
 country. 
 
 Shafted impost: according to Profes- 
 sor Willis, "those imposts which 
 have horizontal mouldings, the 
 sections of the arch above and of 
 the shaft or pier below such hori- 
 zontal mouldings being different." 
 The latter point is the distinction 
 between what he terms shafted 
 and banded imposts : " in banded 
 imposts, the sections above and 
 below the impost-moulding are 
 alike, the shaft or pier seeming to 
 pass through its capital." 
 
 Shaken, plank or timber which is full 
 of clefts, and will not bear caulk- 
 ing or fastening; generally called 
 shakey. 
 
 Shambles, stalls on which butchers 
 expose their meat for sale. The 
 shambles, or market-place for the 
 sale of flesh, at Frankfort-on-the- 
 Maine, is a curious and ancient ex- 
 ample of early shambles. 
 
 Shank, the space between the chan- 
 nels of a triglyph. 
 
 Shank -painter, a chain bolted to the 
 top-side abaft the cat-head, to lower 
 the anchor of a ship. 
 
 Sheave, in mechanics, a solid cylin- 
 drical wheel, fixed in a channel 
 within a block, and movable about 
 an axis ; being used, in connection 
 with suitable tackle, to raise heavy 
 weights, or to increase the me- 
 chanical powers applied to remove 
 any load. 
 
 Sheers, in mining, two very high 
 pieces of wood, placed in nearly a 
 vertical position in each side of a 
 shaft, and united at the top, over 
 which, by means of a pulley, passes 
 the capstan rope : this is for the 
 convenience of lifting out, or lower- 
 ing into the shaft, timber or other 
 things of great length and weight. 
 
 Sheers, in ship-building, etc., are 
 masts or large spars set across each 
 
SHE 
 
 SHINGLE. 
 
 SHI 
 
 other at the upper ends, by .which 
 contrivance the heavy bodies, such 
 as frame-timbers, masts, etc., are 
 raised. 
 
 Sheer-hulk, in the navy, an old se- 
 venty-four cut down to the lower 
 deck, and fitted up with a pair of 
 sheers, for the purpose of taking 
 out the lower masts of ships pre- 
 paring for sea. 
 
 Sheer-strafe, the strake under the 
 gunwale in the top side ; it is ge- 
 nerally worked thicker than the 
 rest of the top-sides, and scarfed 
 between the drifts. 
 
 Sheet, in navigation, a rope fastened 
 to one or both corners of a sail, to 
 extend and retain it in a particular 
 situation. 
 
 Sheet Anchor, in navigation, the 
 largest anchor of a ship. 
 
 Sheriff's Posts, two ornamental posts 
 or pillars, set up one on each side 
 of the house of a sheriff or chief 
 magistrate. 
 
 Shift, the time a miner works in one 
 day. 
 
 Shift, of timber or plank, is over 
 launching without either piece be- 
 ing reduced, as the timbers of the 
 frame, or plank in the bottom. 
 
 Shingle, coarse sand and pebbles de- 
 posited by the surge, accumulating 
 in banks and forming dangerous, 
 shoals. Lieut.-Colonel Reid, in the 
 second volume of the ' Professional 
 Papers' of the Corps of Royal En- 
 gineers, makes the following obser- 
 vations on the moving of the shingle 
 of the beach along the south coast 
 of England : 
 
 " The prevailing winds being 
 westerly, and the highest seas roll- 
 ing from the south-west, the peb- 
 bles of the beach are gradually 
 carried to the eastward, and a con- 
 stant supply is furnished by the 
 falling away of the cliffs. On this 
 coast, therefore, groins so con- 
 structed as to prevent the moving 
 shingle from pressing to the east- 
 ward cause an accumulation of 
 pebbles. 
 
 "It has been ascertained, from 
 
 419 
 
 observation, that the pebbles of the 
 Devonshire coast are forced to the 
 eastward, along the coast of Dor- 
 setshire, as far as the Chesil Bank. 
 The stone pier of Lyme Regis, called 
 the Cobb, does not, as might have 
 been expected, arrest their pro 
 gress ; for, in south-west storms, 
 they are driven over the pier, and 
 the crews in the harbour have had 
 to quit the decks of their vessels, 
 on account of the stones driven 
 over the pier falling on the men. 
 On this account, within a few years, 
 a high wall has been constructed 
 to stop the progress of the shingle 
 at this point. The natural conse- 
 quence to be expected from this 
 wall is, that the shingle will accu- 
 mulate on the west side of Lyme 
 Regis pier, until it shall roll round 
 the pier-head, as at the harbour of 
 Dover. 
 
 "The Chesil Bank is not com- 
 posed of calcareous pebbles (as 
 stated in a work of deservedly very 
 high reputation), but mostly con- 
 sists of siliceous stones, worn to a 
 very remarkable degree of uniform- 
 ity of shape and also of size (when 
 taken from the same point) by long 
 attrition upon the coast. The 
 largest pebbles have been carried 
 furthest to the east ; and the regu- 
 larity with which they are arranged, 
 according to their size, is very re- 
 markable. 
 
 " The progress of the shingle is 
 here first arrested by the Isle of 
 Portland, owing to the projection 
 of that point of land in a line some- 
 what to the westward of south, and 
 the shingle bank stops just where 
 the land trends in a south-west 
 direction. 
 
 " The Chesil Bank, at that part 
 of it nearest the Isle of Portland, 
 is from 20 to 30 feet above the 
 ordinary high-water mark. On the 
 west side it is steep, and the water 
 deep close to the shore; but on the 
 east side it has a gentle slope, with 
 a base of 200 yards, to the above 
 height of 20 or 30 feet. 
 
SHI 
 
 SHINGLE. 
 
 SHI 
 
 " This gentle slope on tb* east 
 side is owing to the accumulation 
 of water on the opposite side during 
 westerly gales, which finds a passage 
 through the gravel bank, washing 
 it into little ravines, and carrying 
 down stones by its current. In 
 very severe storms the sea washes 
 over this bank; and it did so on 
 the 23rd of November, 1824. 
 
 " A dangerous shoal of coarse 
 sand, called the Shambles, which 
 lies off the south-east point of the 
 Isle of Portland, is in all probability 
 formed by the tides; but the Chesil 
 Bank is formed by the waves break- 
 ing on the shore in south-west gales; 
 and it is important that these two 
 causes, and their resulting conse- 
 quences, should always be sepa- 
 rately considered. 
 
 " Siliceous or very hard pebbles 
 only withstand long rolling on the 
 beach, whilst calcareous stones 
 soon become ground into sand. As 
 the siliceous pebbles do not pass 
 round Portland Island, sand only 
 is found on the shore of Portland 
 Roads ; and it is calcareous, effer- 
 vescing strongly with muriatic acid. 
 
 " Scarcely any gravel is to be 
 seen between Portland Roads and 
 Weymouth. Within the ' Aberga- 
 venny,' an East India ship which 
 sank thirty years ago in the mouth 
 of Weymouth Bay, there is no 
 gravel, and very little sand. East 
 of Weymouth it again begins to 
 collect ; but each little headland, 
 acting as a groin, retains much of 
 it in the small bays. Round St. 
 Alban's Head its action has not 
 been observed, but at Christchurch 
 the quantity is considerable, and at 
 Hurst Castie it is very large. 
 
 "The Isle of Wight, and the 
 strong current running through the 
 Needles, here again a second time 
 stop its eastward movement; and 
 it forms, nearly in the mid-channel, 
 a shoal called the Shingles, the 
 easternmost end of which (by the 
 action of the westerly winds on one 
 side, and the current of the Needles 
 
 on the opposite) becomes heaped 
 up above high-water mark into an 
 island, varying in shape and size 
 with every storm, and sometimes 
 disappearing altogether. 
 
 " The pebbles coming from the 
 westward must be driven across the 
 north channel to this bank ; but 
 they do not pass across the south 
 and principal channel of the Needles 
 to the Isle of Wight, as is evident 
 from local inspection ; for those of 
 the Isle of Wight are of a different 
 colour, being black flints from the 
 chalk, whereas those on the side of 
 Hurst Castle are generally yellow. 
 
 " The effect of the prevailing 
 wind, in driving the gravel along 
 the coast from west to east, is not 
 less evident on the south of the Isle 
 of Wight than elsewhere. It passes 
 eastward until it reaches Sandown 
 Bay, where the artificial groins, 
 kept up at considerable cost, arrest 
 a certain portion ; but the surplus 
 is poured over these groins, and, 
 falling on the east side, continues 
 its course. 
 
 " The gravel which passes Ports- 
 mouth does not appear to come 
 from the westward of Hurst Castle, 
 for the shores just within the 
 Needles are mud without stones. 
 A new system commences within 
 the Solent. A large quantity of 
 shingle is furnished from the gra- 
 velly soil of the south coast of 
 Hampshire; and this shingle is 
 likewise driven eastward, some- 
 times returning westward when 
 easterly winds prevail, but the ba- 
 lance of its progress is always to- 
 wards the east. 
 
 " Hurst Castle, Calshot Castle, 
 and Blockhouse Fort, Portsmouth, 
 all stand on similar tongues of 
 shingle, formed on the west sides 
 of their respective passages by the 
 prevailing westerly winds. 
 
 "At Hurst Castle the gradual 
 additions to the end of the strip of 
 shingle may be plainly seen ; for 
 Nature there records her own his- 
 tory in a very visible manner. An 
 
 490 
 
SHI 
 
 SHINGLE. 
 
 SHI 
 
 ordriancelanding-place,30feetlong, 
 which was constructed in 1806, 
 and stood in the sea, became en- 
 tirely buried in gravel ; and many 
 succeeding lines of high- water mark 
 may be distinctly traced to the 
 eastward of Hurst Castle. 
 
 " Similar traces of many former 
 lines of high-water mark are also to 
 be seen near Southsea Castle ; and 
 immediately on the west of Fort 
 Monkton, six distinct lines of high 
 water may be counted ; and some 
 of these probably belong to very 
 remote periods of time. 
 
 "The direction of the line of 
 coast, with reference to the pre- 
 vailing gales, seems to determine 
 where the shingle will accumulate, 
 or where the sea will be most likely 
 to encroach upon the land; and 
 seems to be one of the most im- 
 portant points to study as regards 
 the subject of opening bar-harbours. 
 
 " The south-easterly direction of 
 the beach at Southsea would appear 
 to be one of the causes why the 
 entrance of Portsmouth Harbour is 
 
 kept as clear as it is, by the current 
 running out of it; for this direction 
 of the land prevents the water from 
 spreading itself on both sides, at 
 the ebbing tide, as it does at the 
 entrance of Langston Harbour, over 
 banks of gravel ; and this direction 
 at Southsea appears just sufficient 
 to allow the shingle to be set to the 
 eastward by the prevailing gales. 
 
 " It well deserves consideration, 
 whether embankments (on the south 
 coast of England) run out on the 
 eastward of bar-harbours, in a line 
 parallel to the line formed by nature 
 on the east side of Portsmouth 
 Harbour, would not lead to a simi- 
 lar effect as that produced there by 
 keeping open one principal channel. 
 By a proper system of groins on the 
 west side of such harbours, shingle 
 coming from the westward would 
 be stopped, and much of the ma- 
 terials which now form the bars 
 might be arrested in ther course. 
 
 " The slope of the beach is flatter 
 after a southerly gale, and its aver- 
 age slope is about 1 foot in 9. 
 
 West. 
 
 a 
 
 High-water mark. 
 
 East. 
 
 Foot of the slope of gravel. 
 
 "If groins are not carried far 
 enough in-land, the sea in south- 
 west storms (on the south coast) 
 will break round and insulate them. 
 If they are not high enough at 
 high-water mark, the gravel will 
 
 be carried over them to the east- 
 ward ; and if they are too short, 
 it will pass round the outer end of 
 them. 
 
 " During southerly gales, it is 
 frequently said, that the gravel is 
 
SHI 
 
 SHINGLE. 
 
 SHI 
 
 ' carried into the sea/ because the 
 receding waves draw it down ; but 
 it is again driven back, and if the 
 wind is south-west it is set to the 
 eastward. 
 
 " The preceding figure, in which 
 a pebble (a) passes to (#), fol- 
 lowing a course indicated by the 
 alphabetical order of the letters, 
 will explain what is here meant, 
 and show the way in which the 
 gravel passes by groins which are 
 too short. 
 
 " From this figure it will also be 
 understood, why a single plank re- 
 moved from a wooden groin will 
 cause the beach at such place of 
 removal to be carried on forward.; 
 and hence the importance of con- 
 structing groins of materials not 
 liable to such accidents. 
 
 " The point of shingle on which 
 Calshot Castle now stands was once 
 an island, and called, in 1717, 
 Crown Island ; since which time 
 the opening has filled in with gra- 
 vel. The point on the west side of 
 ChristchurchHarbouris now length- 
 ening annually ; and the mouth of 
 that harbour and its bar become 
 every year more and more removed 
 to the eastward, and if left to na- 
 ture may continue to be removed 
 eastward until the water from that 
 estuary shall re-open a fresh pas- 
 sage for itself in a more direct line, 
 as the water seems to have done at 
 the harbour of Shoreham. 
 
 " At such harbours as Ports- 
 mouth it would be desirable, by 
 means of the apparatus for enabling 
 persons to descend and examine 
 the bed of the sea, to observe and 
 determine the precise mode of the 
 action of the shingle at the entrance 
 of harbours. 
 
 " The sand being blown by the 
 wind, as well as driven by the 
 surge, it frequently covers the 
 coarser shingle, where it is re- 
 tained by the carex arenaria, a 
 grass which roots at every joint." 
 
 (Much valuable information on 
 the subject of encroachments of the 
 
 sea upon the land will be found in 
 Lyell's ' Geology.') 
 
SHI 
 
 SILT. 
 
 SIL 
 
 Shingles, in house-builfling, small 
 pieces of wood sawed to a certain 
 scantling, used in roofing, instead 
 of tiles or slates. 
 
 Shittim wood, a valuable kind of tim- 
 ber, of which Moses made the 
 greater part of the tables, altars, 
 and planks, belonging to the taber- 
 nacle : it grows in the deserts of 
 Arabia, and is like white-thorn in its 
 colour and leaves, but not in size, 
 as the tree is so large that it affords 
 very long planks: the wood is hard, 
 tough, smooth, without knots, and 
 extremely beautiful ; so that the 
 rich and curious make screws of it 
 for their presses. 
 
 Shivers, in navigation, the little round 
 wheels, of wood or metal, in which 
 the rope of a pulley or block 
 runs. 
 
 Sholes, pieces of plank put under the 
 shores where there are no ground- 
 ways. 
 
 Shores, pieces of timber fixed to sup- 
 port a ship. 
 
 Shrines, tombs, or decorated monu- 
 ments of ornamental tabernacle- 
 work, as they are applied to the 
 entombment of royal and noble 
 persons : several very fine examples 
 exist in the cathedrals and abbey 
 churches : the term is also applied 
 to a cabinet in which sacred things 
 are deposited. 
 
 Shunt, a term applicable to the ma- 
 nagement of railway trains, to re- 
 move a carriage or train off the main 
 line. When an engine, carriage, or 
 train is moved off the main line 
 to a siding, it is then said to be 
 ' shunted.' It is most probably de- 
 rived from the word ' shun :' in the 
 old English Romance ' Mort d'Ar- 
 thur' we find the word 'schunte' 
 used in this sense, to put off; and 
 in other early works the word 
 ' shunted' may be found, with the 
 meaning, to move from. 
 
 Side chains, chains and hooks fixed 
 to the sides of the tender and en- 
 gine for safety, should the central 
 drag-bar give way. 
 
 Sidereal year, that space of time 
 
 which astronomers compute the 
 sun is moving from any fixed star 
 till it returns to it again, reckoned 
 at 365 days, 6 hours, and almost 
 10 minutes. 
 
 Sienese School, the school of a lively 
 people ; and is so agreeable in the 
 selection of the colours and the air 
 of the heads that foreigners are cap- 
 tivated, and sometimes even prefer 
 it to the Florentine. But there is 
 another reason for this preference, 
 viz. the choicest productions of 
 the Sienese painters are all in the 
 churches. In Florence it is other- 
 wise ; no picture of Vinci, of Buo- 
 narroti, of Rossi, is tg be seen in 
 public ; none of the finest produc- 
 tions of Andrea or of Frale, and few 
 of the other best masters. The ac- 
 counts of the early Sienese painters 
 are confused by the plurality of 
 the Guidi, the Mini, the Lippi, 
 the Varni (abbreviations of Gia- 
 como, Filippo, Giovanni). To sum 
 up, the character of the School is 
 not so original as some others, and 
 during its best time some of its 
 artists imitated the style of others. 
 Some of the greatest modern names 
 are Giantonio Razzi, surnamed II 
 Sodoma, b. 1479, d. 1554; Do- 
 menico Beccafumi, called Meche- 
 rino, b. 1484, d. 1549 ; Baldassare 
 Peruzzi, b. 1481, d. 1536. 
 
 Signal lamps, railway lamps, with a 
 bull's-eye glass in front. Each 
 lamp has a recess between the 
 burner and bull's-eye, for dropping 
 in any particular coloured glass, 
 according to the light which is to 
 be shown. The lamp has also re- 
 cesses for holding these glasses, so 
 that the engineman can at once 
 pick out a red, green, or blue glass, 
 and put it in front as he may re- 
 quire it. 
 
 Sill, the lower horizontal frame of a 
 door or window ; a threshold. 
 
 Silt, in hydrography, etc., mud depo- 
 sited by rivers, tides, etc., generally 
 in still parts or eddies, and also in 
 lakes or hollows filled with still 
 water. 
 
SIL 
 
 SIPHON. 
 
 SIP 
 
 Silver is sometimes found in the me- 
 tallic state, and as chloride and 
 sulphide, besides alloyed with gold, 
 copper, and other metals. It is 
 a pure white brilliant metal, of 
 great ductility, capable of being 
 drawn out into very fine wires. It 
 melts at 1873, and absorbs a large 
 quantity of oxygen, which, disen- 
 gaging on cooling, gives it a white, 
 frosty appearance : when impure, 
 it does not do so. It is a metal 
 used in great abundance as a coin 
 in all countries, also for plate, for 
 vases, candelabras, cups, etc. 
 
 Sinking, in mining, digging down- 
 wards ; in rising and sinking a 
 shaft, one set of men sink from a 
 certain level, while another set rises 
 from a lower level to meet them. 
 
 Siparium, in the time of the Romans, 
 a piece of tapestry stretched on a 
 frame, which rose before the stage 
 of the theatre. 
 
 Siphon, or Syphon, in hydraulics, a 
 crooked pipe through which liquors 
 are conveyed. 
 
 Siphon. The date of the first appli- 
 cation of the principle by which 
 water or other fluids may be drawn 
 from one level to another by the 
 exhaustion of the air contained in 
 the limb conynunicating with the 
 lower level, appears to be very 
 remote. The Egyptians certainly 
 used it for the transvasing of wine : 
 but the first important application 
 of this principle to useful or general 
 practice was in the aqueduct which 
 conducted the springs of Mount 
 Pila to Lyons : the date of this 
 aqueduct is about 40 years after 
 the commencement of the Christian 
 era. Upon the total length of the 
 aqueduct, which with its branches 
 was 15 old French posting leagues, 
 there were three large siphons to 
 carry the water from the upper 
 sides of the same number of valleys 
 to the lower. Of these, the valley 
 of Chaponest was 2400 feet across, 
 measuring in a straight line across 
 the valley; and it was about 200 
 feet deep. The valley of St. Foy 
 
 424 
 
 was aboat 3,192 feet across, by 300 
 feet deep ; that of St. Trenee was 
 798 feet across, hut much shal- 
 lower. 
 
 The pipes of the Chaponest si- 
 phon, on leaving the upper reser- 
 voir, were 8 inches diameter and 
 1 inch thiek : they were of lead. 
 After running 75 feet of the descent 
 of this dimension, they branched 
 off into two divisions of 6 inches 
 diameter each, in order that the 
 pressure upon the pipes at the 
 lower portion of the siphon might 
 be diminished. They ran over the 
 level bridge in the lower part of 
 the valley of this smaller diameter, 
 and mounted the opposite side for 
 a height of 70 feet, when they re- 
 united into pipes of 8 inches dia- 
 meter again. The total fall of the 
 Chaponest siphon was 150 feet, 
 the rise on the opposite side was 
 130 feet, leaving a difference of 
 level of 20 feet to compensate for 
 the friction. The Siphon of St. 
 Foy had a difference of level, from 
 the upper reservoirs to the straight 
 part, of 240 feet. 
 
 The Lyons aqueduct had in its 
 total length thirteen common 
 straight aqueduct bridges and three 
 siphons ; it delivered very nearly 
 1,300,000 gallons in the twenty- 
 four hours. 
 
 Many writers on hydraulics have 
 failed to notice these extraordinary 
 works, and have expressed their 
 surprise that the ancients were ig- 
 norant of the existence of the law 
 by which water finds its own level. 
 The ancients, however, appear to 
 have wisely preferred the more 
 economical system of carrying 
 water in a straight trough, where- 
 ever the expense was justifiable. 
 Waterworks were, in early times, 
 Government affairs, and the ex- 
 pense of their maintenance was de- 
 liberated. The preceding cases 
 abundantly prove that the ancients, 
 applied the well-known law of hy- 
 drostatical balance whenever they 
 found such a course advisable ; and 
 
SIP 
 
 SKIRLAW. 
 
 SKI 
 
 the details given by Vitruvius re- 
 move all doubt upon the subject. 
 His instructions (lib. 8, c. 7) are as 
 follows : " When the expense of 
 erecting a bridge is too great, a 
 siphon rnay be used ; but this 
 should only be resorted to as a 
 last expedient. The danger of 
 bursting the pipes, and the expense 
 of the repairs, are serious objec- 
 tions to this method, and in the end 
 straight bridges are the cheapest. 
 If, however, it be determined to 
 employ a siphon, it should be laid 
 with a regular curve, and all abrupt 
 elbows avoided. To secure this, a 
 substructure should be raised to 
 fill in any inequalities in the valley 
 where it is to be erected. The 
 last length of the descending pipe 
 and the first of the straight pipe at 
 the level part, as also the last 
 length of the straight pipe and the 
 first ascending one, should be let 
 into a solid stone, which should 
 be carefully fixed and surrounded 
 with ballast, properly rammed." 
 He also gives directions for the 
 construction of air-shafts from the 
 lower parts, which he calls ' co- 
 lumnaria,' and he expressly states 
 that they are necessary to relax the 
 ' vis spiritus in ventris,' the force 
 of the air in the curves. 
 
 Siphon-cups, in steam-engines, cups 
 placed for feeding oil to the work- 
 ing parts of the machinery, trim- 
 med with cotton or worsted, the 
 same as the axle-boxes. 
 
 Sissoo is one of the most valuable 
 timber-trees of India, and with the 
 saulis more extensively used than 
 any other in north-west India. The 
 ship-builders in Bengal select it 
 for crooked timbers and knees ; it 
 is remarkably strong ; its colour is 
 a light greyish-brown with dark- 
 coloured veins. 
 
 Spindlefree, a shrubby tree, with a 
 yellow wood similar to the English 
 boxwood: it is turned into bobbins 
 and common articles. 
 
 Site, the situation of a building ; the 
 plot of ground on which it stands. 
 
 425 
 
 Site, in landscape, signifies the view, 
 prospect, or opening of a country, 
 derived from the Italian word sito, 
 situation ; and it is in use among 
 painters, as being more expressive. 
 
 Sketch, a slightly-made picture, in 
 which the general effect is attended 
 to, but not always the details, and 
 from which more finished works 
 are painted : so also with sketches 
 in architecture, giving the correct 
 outline of a building without filling 
 up with the detail. 
 
 Skew, or Askew, as applied to masons' 
 work, an oblique arch. 
 
 Skirlaw, Walter, when prebend of 
 Fenton, in 1730, took down the 
 middle tower of York cathedral, 
 built by John Romanus, and built 
 the present noble tower in its stead, 
 at his own expense. It was built 
 in six or seven years. " Walter ap- 
 pears to have been a munificent 
 prelate, and an architect of uncom- 
 mon genius. The tower above-men- 
 tioned would have been sufficient to 
 establish this character; but that 
 part of Howden Church, about 18 
 miles from York and Beverley, 
 shows a richness of fancy and de- 
 licacy of taste equally adapted to 
 smaller structures. The Chapter- 
 house struck me as eminently beau- 
 tiful. A small chapel built by him, 
 called Shinlaw Chapel (which I 
 believe is the name of the village), 
 is worthy of attention for its chaste 
 and elegant style. It is a few miles 
 from Hull and from Beverley. All 
 these I have seen, and can speak of 
 them confidently. Walter Shirton 
 was made Bishop of Lichfield 
 and Coventry, then of Bath and 
 Wells, and afterwards of Durham, 
 where he continued seventeen 
 years. He built the bridges of 
 Shinkley, and Auckland, and Yar- 
 row; also a chapel at Swine, in 
 Holderness (Query, is not this the 
 chapel above mentioned, which is 
 called Skirlaw Chapel ?), where he 
 was born. He built also the steeple 
 of Holme, and repaired the church 
 and manor there" (Gent). He be- 
 
SKI 
 
 SLIDE-REST. 
 
 SLI 
 
 stowed above 800 (a large svjjn in 
 those days), while Bishop of Dur- 
 ham , towards building the dormitory 
 and cloister of the monastery in that 
 city, and left several sums of money 
 to the churches he had governed, 
 particularly to that of Wells, to buy 
 ornaments for the decent perform- 
 ance of divine service. He was 
 buried in the cathedral of Durham, 
 southward of the choir. From the 
 epitaph we learn that he died 24th 
 March, 1405. Under this prelate 
 Gothic architecture seems to have 
 attained its highest excellence. 
 
 Skirting, a narrow board forming a 
 plinth to an internal wall. 
 
 Skreens were either of needlework 
 or painted : in the time of Henry 
 VIII. is noticed a skreen as a new 
 year's gift from Luke Hornebound, 
 a painter, to that monarch. 
 
 Skylights, glass frames placed in a 
 roof with one or more inclined 
 planes of glass. 
 
 Slaking of Lime, Quick-lime, taken 
 as it leaves the kiln, and thrown 
 into a proper quantity of water, 
 splits with noise, puffs up, produces 
 a large disengagement of slightly j 
 caustic vapour, and falls into a j 
 thick paste. So much heat is pro- ! 
 duced in slaking, that part of the I 
 water flies off in vapour. If the 
 quantity of the lime slaked be 
 great, the heat produced is suffi- I 
 cient to set fire to combustibles : i 
 in this manner vessels loaded with ' 
 lime have sometimes been burnt. ; 
 When great quantities of lime are 
 slaked in a dark place, not only 
 heat, but light also, is emitted. 
 The specific gravity of pure lime 
 is 3-08. 
 
 Slate, an argillaceous stone, readily 
 split, and employed to cover build- 
 ings, arid also for other purposes : 
 it is quarried in large pieces. 
 
 Slating is employed by builders for 
 covering in the roofs of buildings. 
 The slates principally in use in Lon- 
 don are brought from North Wales. 
 
 Sleepers, pieces of timber employed 
 to support others, and laid asleep, 
 
 426 
 
 or with a bearing along their own 
 length : sleepers denote more par- 
 ticularly those timbers which are 
 placed lengthwise on walls to sup- ; 
 port the joists of a floor ; they are 
 employed on railroads as longitu- 
 dinal bearings for the rails to rest 
 upon. 
 
 Sleepers, or Transome-knees, are fixed 
 withinside a ship abaft, one arm 
 laying on the foot waleing, and the 
 other extended up the transoms. 
 
 Slickings^ narrow veins of ore. 
 
 Slide, a vein of clay, which, intersect- 
 ing a lode, causes a dislocation ver- 
 tically. 
 
 Slide'rest. This apparatus, the in- 
 vention of Mr. Henry Maudslay, is 
 of the utmost importance for per- 
 fecting and accelerating the con- 
 struction of machinery. Before 
 its invention, cylindrical turning 
 was a work of manual labour, and 
 was attended with so much diffi- 
 culty and expense, when the cylin- 
 ders were either large in diameter 
 or of moderate length, that it was 
 necessary to avoid using them in 
 many cases ; and plane surfaces 
 being even still more expensive, in 
 consequence of the very imperfect 
 and laborious operations of chipping 
 and filing them, many very valuable 
 inventions could not be carried into 
 effect on account of the inaccuracy 
 and expense attending their con- 
 struction. The invention of the 
 slide-rest, forming an all-important I 
 part of that of the planing machine, 
 has entirely removed both of these 
 difficulties, and cylindrical turning 
 and planing are now the cheapest 
 and most perfect of mechanical 
 operations. 
 
 The office of the slide-rest, as 
 applied to lathes and turning ma- 
 chines, is to hold, engage, and direct 
 the turning-tool, and it may be kept 
 in motion either by hand or by self- 
 acting machinery. 
 
 When applied to a small lathe, 
 it is generally moved by hand ; 
 but in large machines for heavy 
 work, where the time of action is 
 
SLI 
 
 SLIDE-VALVE. 
 
 SLI 
 
 considerable, it is moved by ma- 
 chinery attached to the lathe. The 
 work to be turned being placed in 
 the usual way between the two 
 centre pieces of the lathe, the 
 lower part of the slide-rest is fixed 
 under it on what is called the bed 
 of the lathe : the use of this part of 
 the slide is to move the tool to or 
 from the work, which it effects by 
 means of a slide, at right angles to 
 the work, moved by a screw and 
 handle: this s de has fixed upon 
 it, by a swivel joint, the upper part 
 of the apparatus. 
 
 The upper part has also a slide 
 moved by a screw and handle, and 
 generally placed at right angles to 
 the lower slide : the principal use 
 of this upper slide is to move the 
 cutting-tool which is fixed upon it 
 parallel to the centre line of the 
 
 Fig. i. 
 
 lathe ; but it can be so placed, by 
 aid of the swivel-joint, as to cause 
 the tool to advance at any required 
 angle with the centre line of the 
 lathe. Thus two direct movements 
 are obtained : the first to set the 
 tool to the work, and the second 
 to move it either to the right or 
 left, in a line parallel with the 
 work, or at any given angle with 
 the first. 
 
 The slide-rest principle enters 
 largely into the construction of all 
 kinds of machinery, from the most 
 minute to machines of vast magni- 
 Fude, where by its aid ponderous 
 masses such, for instance, as rail- 
 way turn-tables 36 feet in diame- 
 ter are operated upon with a 
 precision unattainable by any other 
 means. 
 Slide-valve, in locomotive engines, the 
 
 Fig. 3. 
 
 427 
 
SLI 
 
 SLIDE-VALVE. 
 
 SLI 
 
 valve placed in the steam -chest to 
 work over the steam-ports. It 
 regulates the admission of steam 
 to the cylinder from the boiler, 
 and the escape of the steam from 
 the cylinder to the atmosphere. 
 Its form is that of an arch in the 
 centre, with a flat face all round 
 to keep it steam-tight on the face 
 of the steam-ports. It is by the 
 arched part that the steam escapes 
 to the atmosphere. It is a very 
 simple valve, and answers its pur- 
 pose well, with one drawback, 
 namely, the pressure of the steam 
 upon it being unbalanced by any 
 counter-pressure. Numerous at- 
 tempts have been made to relieve 
 this pressure, some of which it is 
 hoped will be successful. In sta- 
 tionary engines the contrivances 
 differ materially, as shown in the 
 woodcut, Figs. 1, 2, 3. 
 
 Fig. 1 represents in section the 
 cylinder, piston, and slide : S is the 
 mouth of the steam-pipe coming 
 from the boiler ; e is the pipe lead- 
 ing to the condenser ; t is the rod 
 which is attached to the slide, 
 moving through a stuffing-box, ra n, 
 This slide is represented in longi- 
 tudinal section, separately, in fig. 3, 
 and in transverse section in fig. 4. 
 In the position of the slide repre- 
 sented in fig. 1, the steam passing 
 from the boiler enters at S, and 
 passes to the bottom of the cylin- 
 der through the opening 6, where 
 it acts below the piston, causing it 
 to ascend. The steam which was 
 above the piston escapes through 
 the opening at a, and descending 
 through a longitudinal opening in 
 the slide behind the mouth of the 
 steam-pipe, finds its way to the 
 pipe e, and through that to the 
 condenser. 
 
 When the piston has reached 
 the top of the cylinder, the slide 
 will have been moved to the posi- 
 tion represented in fig. 2. The 
 steam now entering at S passes 
 through the opening a iijto the 
 cylinder above the piston, while 
 
 428 
 
 the steam which was below it es- 
 capes through the opening b and 
 the pipe e to the condenser. 
 
 The form of the valve, 
 from which it derives 
 its name of D-valve, is 
 represented in fig. 4. 
 The longitudinal open- 
 ing through which the 
 steam descends then 
 appears in section of a 
 semicircular form. The packing at 
 the back of the slide is represented 
 at ; this is pressed against the 
 surface of the valve-box. 
 Slide-valve lap, Outside, in locomotive 
 engines, that portion of valve which 
 would overlap the steam-ports when 
 placed over them. If the steam- 
 ports measure 8 inches over all the 
 ports, and the valve be 10 inches 
 broad, this would be an overlap of 
 1 inch on each side of the ports, 
 and is called the ' lap' of the valve. 
 Expansion was formerly regulated 
 by the extent of lap only, but it is 
 now regulated by both the lap and 
 the expansion gear, which gives 
 greater scope in doing so. Inside 
 lap is the portion of the valve-face 
 which would overlap the inside of 
 the steam-ports when placed over 
 them ; for if the steam-ports were 
 4 inches from inside of the one 
 port to the inside of the other 
 port, and if the arched part of the 
 valve only measured 3| inches 
 across, this would give -j- 1 ^ of an 
 inch lap on each side, which is 
 called inside lap. 
 
 Slide-valve lead, in locomotives, the 
 width which the steam-port is 
 opened by the slide-valve when the 
 piston is at the end of the stroke. 
 It varies from -i to an inch, accord- 
 ing to the work required. The lead 
 is obtained by fixing the eccentric 
 on the axle, a little in front of the 
 crank, by which arrangement the 
 steam-port is opened in front of 
 the direction in which the piston 
 is moving before the latter has 
 completed its stroke. By these 
 means the steam-port is thrown 
 
SLI 
 
 SLIDE-VALVE. 
 
 
 
 SLI 
 
 quickly open when the piston com- 
 
 and 
 
 the expansion gear so far 
 
 mences its return stroke, and has 
 
 affect 
 
 the working of the slide. 
 
 at once the full pressure 
 
 of the 
 
 that 
 
 it is necessary to take the 
 
 steam against it. 
 
 
 front 
 
 and back stroke 
 
 working 
 
 Slide-valve travel, the distance which 
 
 separately. 
 
 the slide-valve travels in one direc- 
 
 Setting the slide-valve: 
 
 the ec- 
 
 tion for each stroke of the 
 
 piston. 
 
 centric is brought as much before 
 
 This is from 4 to 5|- inches gene- 
 
 the crank as to 
 
 give the 
 
 required 
 
 rally, hut is reduced by each varia- 
 
 lead 
 
 to the slide-valve when the 
 
 tion of the expansion gear, 
 
 and its ' 
 
 crank 
 
 is on the centre, that is, in a 
 
 travel is taken for both the front 
 
 straight line with a cylinder. The 
 
 and back strokes of the piston for 
 
 handle is then moved to each sepa- 
 
 each notch where the handle is 
 
 rate notch, and the position of the 
 
 fixed. The up-and-down quarter- 
 
 slide and piston 
 
 carefully taken for 
 
 revolutions of the crank do not 
 
 each variation. 
 
 These are 
 
 then re- 
 
 equally draw the piston the half- 
 
 corded in the following manner : 
 
 length of the cylinder, and this 
 
 Slide-valve and Piston Motions' Register. Working of expansion gear. 
 
 
 Engine, 
 
 
 
 185 
 
 
 
 
 
 
 
 Inches. 
 
 
 
 
 Inches. 
 
 Diameter of cylinders . . 
 
 18 
 
 Outside lap of valve . . 
 
 1 
 
 Length of stroke .... 
 
 24 
 
 Inside lap of valve . . . 
 
 A 
 
 Size of steam-port . . . 
 
 15 x 2 
 
 Size of 
 
 exhaust-port . . 
 
 15x3 
 
 revers- 
 
 
 
 Steam cut 
 off. 
 
 Exhaust 
 opens. 
 
 Compres- 
 sion begins. 
 
 Steam-port 
 opens. 
 
 
 REMARKS. 
 
 Ja '^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 g.i 
 
 
 
 <*- "3 
 
 
 
 is 
 
 
 
 2 g 
 
 1 
 
 d 
 
 1 
 
 1 
 
 Ic 
 
 j 
 
 2g 
 
 2 c 
 
 it 
 
 
 
 60 
 
 ?.% 
 
 11 
 
 |t 
 
 g'B. 
 
 | : 
 
 i. 
 
 g'i. 
 
 fi 
 
 |1 
 
 |1 
 
 -Si 
 
 M 
 
 
 
 KJ 
 
 HT3 
 
 J-S 
 
 
 PQ*o 
 
 
 
 o 
 
 w^ 
 
 fi^ 
 
 
 s*s 
 
 cqt 
 
 as 
 
 Balance piston 
 
 
 In. 
 
 In. 
 
 In. 
 
 In. 
 
 In. 
 
 In. 
 
 In. 
 
 In. 
 
 Iii, 
 
 In. 
 
 In. 
 
 for slide- 
 valves. 
 
 1 
 
 H 
 
 H 
 
 19* 
 
 19 
 
 22f 
 
 22f 
 
 22i 
 
 22^ 
 
 .1* 
 
 If 
 
 H 
 
 
 
 2 
 
 ^ 
 
 ** 
 
 18* 
 
 18 
 
 22* 
 
 211 
 
 22, 
 
 21* 
 
 1* 
 
 If 
 
 ,, 
 
 
 
 3 
 
 4 
 
 ft 
 
 16* 
 
 16A 
 
 M| 
 
 21i 
 
 2H 
 
 21 
 
 if 
 
 1* 
 
 
 
 
 
 4 
 
 3* 
 
 *i 
 
 13* 
 
 13* 
 
 20 T % 
 
 19 ii 
 
 20 
 
 19* 
 
 
 
 i* 
 
 M 
 
 
 
 5 
 
 3* 
 
 & 
 
 91. 
 
 10 
 
 18 1 
 
 -V 
 
 18^L 
 
 18 
 
 17- 9 
 
 9 
 
 T 9 7" 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 2entr 
 
 e notch. 
 
 6 
 
 2i* 
 
 H 
 
 ^ 
 
 6 
 
 15 
 
 1 
 
 r 
 
 15 
 
 1H 
 
 1* 
 
 to 
 
 ** 
 
 
 
 
 
 The above measurements are carefullv taken and 
 
 registered 
 
 by the mechanic 
 
 who 
 
 sets the slide-valves. 
 
SLI 
 
 SMELTING. 
 
 SME 
 
 Slide-valve rod guide, in locomotive 
 engines, a bracket fixed to the 
 boiler, the lower end of which is 
 fitted for the slide-valve rod to 
 work through. A set-screw is use- 
 ful in this guide for fixing the rod 
 when the valve has to be discon- 
 nected. 
 
 Slide-valve rod and frame, in loco- 
 motive engines : the frame is fitted 
 on to the top part of the valve, 
 and the rod connects the frame 
 with the slide-block, or rocking- 
 shaft, according to the description 
 of valve-gear of the particular 
 engine. 
 
 Slide-valve motion, in locomotive en- 
 gines, a short motion similar to the 
 piston-rod motion, connecting the 
 quadrant to the slide-valve by 
 parallel guides. 
 
 Slidmy rule, a rule constructed with 
 logarithmic lines, formed upon a 
 slip of wood, brass, or ivory, in- 
 serted in a groove, in a rule made 
 to slide longitudinally therein, so 
 that by means of another scale 
 upon the rule itself the contents of 
 a surface or solid may be known. 
 
 Slimes, mud containing metallic ores, 
 mud or earthy particles mixed with 
 the ores. 
 
 Slit deal, a name for inch and a quar- 
 ter-inch deal cut into two boards. 
 
 Sloop, in navigation, a small one- 
 masted vessel, the mainsail of 
 which is attached to a gaff above 
 and to a long boom below. The 
 word is also applied to any small 
 ship. 
 
 Sluice, in hydraulics, a water-gate, a 
 flood-gate, a vent for water. 
 
 Smelting, is the process of separating 
 metals from the earthy and other 
 matters with which they are com- 
 bined in the state of ore. Of this 
 operation, as conducted upon the 
 ores of iron, copper, lead, and tin, 
 the following is a brief description. 
 Smelting Iron. The reduction of 
 iron ore is effected in a furnace in 
 which, the required intensity of 
 heat being obtained by a current of 
 air driven rapidly into the furnace, 
 
 430 
 
 has received the name of a blast- 
 furnace. The kind of furnaces em- 
 ployed, the quantity of ore or mine, 
 as it is termed, reduced at each 
 heat, and the peculiar method of 
 conducting the operation, vary 
 widely in different countries and 
 counties, and have some reference 
 in detail to the precise quality and 
 composition of the ore to be treat- 
 ed. Previous to the year 1740, the 
 smelting of ores of iron was, in 
 England, performed solely with the 
 charcoal of wood, the ores operated 
 upon being principally the brown 
 and red hematites, or rich ores, 
 that is, containing alarge proportion 
 of metal with a small quantity of 
 earthy materials. In the treatment 
 of this class of ores, it may be ob- 
 served that very little improvement 
 has yet been effected, the modern 
 process having been chiefly ap- 
 plied to the leaver ores, such as 
 blackband, etc. The expensiveness 
 and comparative scarcity of char- 
 coal as a fuel for the smelting of 
 iron ores, induced those engaged in 
 the art to attempt the substitution 
 of coal for wood-charcoal ; and by 
 the year 1788, these attempts had 
 so far succeeded, that there remain- 
 ed only 24 out of 59 charcoal fur- 
 nacles, while 53 furnaces had been 
 established in which coal, burned 
 into the form of coke, was used for 
 the smelting of the ore. Since that 
 date, the extension of this process 
 has proceeded rapidly, and the 
 total quantity of metal produced 
 has experienced a corresponding 
 augmentation. At the present time, 
 the Backbarrow Iron Company are 
 nearly the only smelters of iron 
 with wood-charcoal in the kingdom. 
 The two principal seats of the iron 
 manufacture in Great Britain are in 
 Staffordshire and South Wales. In 
 the former district, comprising the 
 neighbourhoods of Dudley, Bilston, j 
 "VVednesbury, etc., the smelting or j 
 blast furnaces are constructed al- i 
 most wholly of bricks. They are 
 usually of a conical form exter- 
 
SME 
 
 SMELTING. 
 
 SME 
 
 nally, and sometimes pyramidal, the 
 plan being a square or rectangle. 
 In the interior they are mostly cir- 
 cular in form, except in that part 
 called the hearth. The fuel and 
 the ore to be smelted are fed into 
 the furnace from the top, and its 
 height being from 40 to 50 feet, an 
 ascendingplatformorinclinedplane 
 is constructed for wheeling up the 
 barrows in which the materials are 
 conveyed. The pipes through which 
 the air is driven into the furnace 
 (by a steam-engine) are called the 
 | tuyeres, and are usually two, but 
 sometimes three in number. The 
 relative quantities of coal, iron- 
 stone, and limestone, which are 
 put into the smelting furnaces of 
 Staffordshire for the production of 
 each ton weight of iron produced, 
 are about 50 cwt. of coal, 50 cwt. 
 of mine, previously calcined, and 
 from 12 to 16 cwt. of limestone, 
 the latter material being added as 
 a flux to promote the fusion of the 
 mass. The Conegree furnace, near 
 Dudley, may be instanced as a 
 good example of a blast-furnace 
 adapted for the economical smelt- 
 ing of iron ores. It is 54 feet in 
 height, 5 feet in diameter on the 
 hearth, and 12 feet above, widening 
 upward to a diameter of 13 feet 
 9 inches, and reduced to 8 feet 
 above the platform, on which the 
 charges are delivered. The quan- 
 tities of materials employed in this 
 furnace to make one ton of r>ig- 
 iron, are of coal 2 tons and 5 cwt., 
 or of coke 37 cwt., charred mine 
 2 tons 5 to 10 cwt., limestone 13 
 to 16 cwt. 
 
 Each charge delivered into the 
 furnace consists of 9| cwt. of coke, 
 12 cwt. of charred mine, and 4 cwt. 
 of limestone. At this furnace 115 
 tons of pig-iron have been made 
 in one week. The cylinder from 
 which the air is blown through the 
 tuyeres into the furnace is 72 in. 
 in diameter, and the stroke is 7 feet 
 in length. Originally there were 
 five tueres for the introduction 
 
 of the blast, one muzzle being 2, 
 two others 2, and the other two 
 2 inches in diameter. Subsequently 
 these were changed to four muz- 
 zles, of the respective diameters 
 of 3, 2, 2, and 2 inches. 
 
 Smelting Copper. Copper ore, 
 as smelted in SouthWales and other 
 places, usually consists of pyrites 
 (composed of sulphuret of copper 
 and sulphuret of iron in nearly 
 equal proportions) and vein-stone. 
 The earthy matters combined with 
 the pyrites are commonly siliceous, 
 and the process of smelting consists 
 in alternate roastings and fusions. 
 The first of these operations is, cal- 
 cining the ore in furnaces in which 
 the heat is applied, and increased 
 gradually, till the temperature be 
 as high as the ore can support 
 without melting or agglutinating, 
 when the ore is thrown into an 
 arch formed under the sole of the 
 furnace. The second operation, or 
 fusion of the calcined ore, is per- 
 formed in a luted furnace, the ore 
 having been spread uniformly over 
 the hearth, and fluxes, such as lime, 
 sand, or fluor-spar, being added 
 when required, although the ne- 
 cessity for this addition is sought 
 to be obviated by a careful admix- 
 ture of ores of different qualities, 
 the several earthy components of 
 which shall serve as fluxes in the 
 fusion of the mass. These two 
 processes of calcination and fusion 
 are completed alternately until the 
 ore is completely freed from all 
 the earthy materials, and pure 
 metal is obtained. 
 
 Smelting Lead. The ores of lead, 
 after being sorted, cleansed, ground, 
 and washed, are roasted in furnaces, 
 which are without any blast or 
 blowing apparatus, the ores being 
 separable from the metal by its 
 great fusibility. Several of the 
 furnaces are usually connected with 
 one chimney-stalk, to which a 
 series of flues about 18 inches 
 square conduct. The melted lead 
 runs freely from the ore, and is 
 
SMO 
 
 SMOKE. 
 
 SMO 
 
 drawn off into the moulds in suc- 
 cessive quantities, the ore being 
 repeatedly turned over, and a small 
 quantity of coal added over the 
 burning mass at each drawing. 
 
 Smelting Tin. This process con- 
 sists of the calcining or roasting of 
 the ores after they have been clean- 
 ed, sorted, stamped, and washed. 
 The calcining is performed in a re- 
 verberatory furnace from 12 to 15 
 feet long and 7 to 9 feet wide. The 
 hearth of these furnaces is hori- 
 zontal, and they have only one 
 opening, which is in the front, and 
 closed by an iron door. The sul- 
 phureous and arsenical vapours 
 which arise from the ore are con- 
 ducted by chimneys over the doors 
 of the range of furnaces into hori- 
 zontal flues, in which the acid is 
 condensed. In the process of cal- 
 cination, which occupies from 12 
 to 18 hours, according to the quan- 
 tity of pyrites contained in the ore, 
 6 cwt. of ore are treated at once, 
 and the materials are stirred from 
 time to time, to prevent them from 
 agglutinating. 
 
 Smoke, Prevention of. There is per- 
 haps no subject so difficult, and 
 none so full of perplexities, as that 
 ^of the management of a furnace, 
 and the prevention of smoke. Mr. 
 Fairbairn, in his report to the Bri- 
 tish Association on the Combus- 
 tion of Fuel and the Prevention of 
 Smoke, observes : " I have ap- 
 proached this inquiry with consi- 
 derable diffidence, and after re- 
 peated attempts at definite con- 
 clusions, have more than once 
 been forced to abandon the inves- 
 tigation as inconclusive and unsa- 
 tisfactory. They chietly arise from 
 the constant change of tempera- 
 ture, the variable nature of the vo- 
 latile products, the want of system, 
 and the irregularity which attends 
 the management of the furnace. 
 Nevertheless, the prevention of 
 smoke and the perfect combustion 
 of the fuel, are completely within 
 the reach of all who choose to 
 
 439 
 
 adopt measures calculated for the 
 suppression of the one and the 
 improvement of the other. 
 
 " On presenting to the British 
 Association an inquiry into the 
 merits of Mr. C. Wye" Williams's 
 Argand furnace compared with 
 those of the usual construction, 
 it was found from an average of 
 a series of experiments, that the 
 saving of fuel (inclusive of the ab- 
 sence of smoke) was in the ratio 
 of 292' to 300, or as 1 : 1-039, 
 being at the rate of 4 per cent, 
 in favour of Mr. Williams's plan. 
 Since then a considerable number 
 of experiments have been made by 
 Mr. Heuldsworth, Mr. Williams, 
 and others, which present some 
 curious and interesting phenomena 
 in the further development of this 
 subject." 
 
 When these trials were made 
 many of the details of the construc- 
 tion of furnaces were but imper- 
 feqtly understood and applied, and 
 hence the amount of economy was 
 far short of what has since been 
 realized. Among the more recent 
 experiments, as illustrative of the 
 practicability of effecting perfect 
 combustion of the fuel employed, 
 may be mentioned those made by 
 Sir W. Armstrong, Dr. Richard- 
 son, and Mr. Layridge, to whom 
 the inquiry was entrusted by the 
 Colliers' Association of Newcastle. 
 Of these trials an ample report was 
 made, and has since been pub- 
 lished, which will well repay ex- 
 amination. Sufficient information 
 is there given of the requirements 
 of furnaces, and the practical de- 
 tails of their relative proportions. 
 These competent judges in this 
 case decided in giving preference 
 to the principles and practice 
 adopted by Mr. Williams, stating 
 their unanimous opinion " That 
 Mr. Williams must be declared the 
 successful competitor, and there- 
 fore award him the premium of 
 500 offered by the Association." 
 
 In their Report they state as an 
 
>MO 
 
 SMOKE. 
 
 SMO 
 
 important feature of the success- 
 ful plan, that " It may be applied 
 under varied circumstances, pro- 
 ducing a more complete absorption 
 of the heat generated, with a great 
 increase in the economic value and 
 work done." In this respect the 
 practical result was as near the 
 theoretic value of the fuel, as per- 
 haps will ever be effected. 
 
 Mr. Williams's plan, independent 
 of the details of the furnace, re- 
 lied on the introduction of the re- 
 quired quantity of air through se- 
 veral hundred half-inch orifices in- 
 serted in the door-box, and above 
 it. As the entire question of the 
 proper combustion of the fuel 
 depends on the admission and ac- 
 tion of the air, it may here be use- 
 ful to state that each ton of bitu- 
 minous coal produces, on an aver- 
 age, 10,000 cubic feet of gas; and 
 further, that each cubic foot of this 
 gas requires for its combustion 10 
 cubic feet of air at atmospheric tem- 
 perature. That this is independent 
 of the quantity required for the 
 combustion of the coke portion of 
 the coal, and which is estimated at 
 double the quantity required by 
 the gas. Thus, then, 100,000 cu- 
 bic feet of air are absolutely ne- 
 cessary for the combustion of the 
 gas alone of each ton of coal, and 
 200,000 for the coke of the same 
 ton weight. 
 
 On the question of quantity, 
 then, there is no doubt or difficulty. 
 The next point for consideration 
 is as to the place and mode of 
 introducing this large quantity of 
 air, so that the necessary admix- 
 ture of the air and the gas may be 
 effected. On these points Mr. Wil- 
 liams, in his treatise on the com- 
 bustion of coal, states : " With 
 reference to the place for the ad- 
 mission of the air, it is a matter 
 of perfect indifference, as to effect, 
 in what part of the furnace it is 
 introduced, provided the all-im- 
 portant condition be attended to, 
 namelv, that the mechanical mix- 
 
 ture of the air and the gas be con- 
 tinuously effected before the tem- 
 perature of the carbon of the. gas 
 (then in the state of flame) be 
 reduced below that of ignition ; 
 this temperature, according to Sir 
 H. Davy, being 800. 
 
 With reference to the propor- 
 tion of the several parts of a fur- 
 nace, it has been practically ascer- 
 tained that in the chamber of the 
 furnace there should never be less 
 than 2 feet between the bars and 
 the crown-plate. That an ade- 
 quate space of at least double the 
 area of the furnace be appropri- 
 ated behind the bridge as a com- 
 bustion chamber, in which the 
 process of mixture and chemical 
 union may be effected. Further, 
 that there should be a distance or 
 run between the furnace and the 
 tubes, if any, of not less than ten 
 feet lineals in which the process 
 is continued. 
 
 In the experimental furnaces at 
 the Newcastle trial, the area of ad- 
 mission for the air was equal to 4 
 inches square for each square foot 
 of grate-bars. 
 
 The prevention of smoke is so 
 directly connected with the con- 
 struction of boilers, as to render it 
 necessary to refer to the plan now 
 almost universally adopted, namely, 
 the multitubulous plan. On this 
 point there is a great diversity of 
 opinion among engineers. By nu- 
 merous improvements made by 
 Mr. Williams, Mr. Dewrance, and 
 others, it has been ascertained that 
 the value of the tubes as heat- 
 absorbing surface has been greatly 
 overrated. It appears, practically, 
 that with the exception of the first 
 12 or 24 inches of the tubes, the 
 remainder have very little steam- 
 generating effect, and that as a 
 general principle the effective heat- 
 ing surface of tubes should only be 
 estimated at one-tenth of their su- 
 perficial area. That when coal is 
 used the tubes are seriously pro 
 ductive of smoke, and its accom- 
 
SMO 
 
 SNAKE WOOD. 
 
 SOL 
 
 paniment, soot. Considerably at- 
 tention has been given of late to 
 this point, since the economy in 
 the use of coal instead of coke in 
 locomotives has been so fully as- 
 certained. With the view of avoid- 
 ing the nuisance of smoke in lo- 
 comotives, their construction has 
 of late been much modified. The 
 necessity for a second, or com- 
 bustion chamber, is now gene- 
 rally admitted, thus assimilating 
 their construction to that of ma- 
 rine boilers, as already described. 
 So insufficient has been the effect 
 of tubes as steam generators, and 
 so injurious are they in the gene- 
 ration of smoke, that an impor- 
 tant change will no doubt short- 
 ly take place. It is even now 
 found by successful practice on 
 the London and North-western 
 Railway, that while the combus- 
 tion-chambers are much enlarged, 
 the tubes are no more than 22 
 inches in length. More recently 
 Mr. C. Wye Williams has proved 
 his complete success in the accom- 
 plishment of all that can be de- 
 sired ; his prize at the Society of 
 Arts, and the award of 500 by 
 the Newcastle Association, are 
 proofs of his superiority over his 
 compeers. 
 
 Smoke-box, the end of the boiler on 
 which the chimney is placed. Loco- 
 motives with inside cylinders have 
 them placed in this box, which 
 keeps both them and the steam- 
 pipes at a high temperature. 
 
 Smoke-box door, the door in front of 
 the smoke-box, by which access is 
 gained to the cylinders or steam- 
 pipes, and other parts placed in 
 this box. 
 
 Snake wood, a kind of speckled wood 
 used in Demerara, Surinam, etc., 
 for the bows of the Indians : the 
 colour of the wood is red hazel, 
 with numerous black spots and 
 marks, which have been tortured 
 into the resemblance of letters, or 
 the scales of reptiles. W r hen tine, 
 it is very beautiful, and is scarce in 
 
 434 
 
 England : chiefly used for walking- 
 sticks, which are expensive. The 
 pieces that are from 2 to 6 inches 
 in diameter are said to be the pro- 
 duce of large trees. 
 
 Snow, in navigation, the largest of 
 European two-masted vessels. The 
 sails and rigging are exactly similar 
 to those of a ship, only behind the I 
 mainmast of a snow there is a j 
 small spar or mast, fixed into a j 
 block of wood on the quarter-deck, \ 
 which carries a sail resembling the 
 mizen of a ship. 
 
 Snying, in navigation, a circular plank 
 edgewise, to work in the bow. 
 
 Socle, in architecture, a flat square 
 member under the bases of the 
 pedestal of statues and vases. 
 
 Sojfit, in architecture, any timber 
 ceiling formed of cross-beams or 
 flying cornices, tbe square com- 
 partments or panels of which are 
 enriched with sculpture, painting, 
 or gilding. 
 
 Sol, in heraldry, denotes or, the golden 
 colour in the arms of sovereign 
 princes. 
 
 Solar month, that space of time oc- 
 cupied by the sun in going through 
 one sign or a twelfth part of the 
 zodiac. 
 
 Solar System, in astronomy, the 
 order or supposed disposition of 
 the celestial bodies which move 
 round the sun as the centre of 
 their motion. 
 
 Solar year, that space of time in 
 which the sun returns again to the 
 same equinoctial or solstitial point, 
 which is about 365 days, 5 hours, 
 and 50 minutes. 
 
 Soldering is the process of uniting the 
 edges or surfaces of similar or dis- 
 similar metals and alloys, by partial 
 fusion. In general, alloys or solders 
 of various and greater degrees of 
 fusibility than the metals to be 
 joined, are placed between them, 
 and the solder, when fused, unites 
 the three parts into a solid mass: 
 less frequently the surfaces or edges 
 are simply melted together with an 
 additional portion of the same metal. 
 
SOL 
 
 SOUND. 
 
 SOU 
 
 Sole, the seat or bottom of a mine, 
 applied to horizontal veins or lodes. 
 
 Solidity, in geometry, the quantity of 
 space contained or occupied by a 
 solid body ; called also its solid con- 
 tents, estimated by the number of 
 solid or cubic inches, feet, yards, 
 etc., which it contains. 
 
 Solids are all bodies that have the 
 three dimensions; and among geo- 
 metricians those that are termi- 
 nated by regular planes are called 
 regular solids, such as the tetra- 
 hedron, hexahedron, octahedron, 
 dodecahedron, and icosahedron. 
 
 Sondelets of iron, used for the win- 
 dows of St. Stephen's chapel, are 
 fastenings and cross-mullions. 
 
 Sough, an adit or level for carrying 
 off water. 
 
 Sound is produced by a sudden shock 
 or impulse given to the air : these 
 impulses, if quickly repeated, can- 
 not be individually attended to by 
 the ear, and hence they appear as 
 one continued sound, of which the 
 pitch or tone depends on the num- 
 ber occurring in a given time ; and 
 all continued sound is but a repe- 
 tition of impulses. 
 
 The motion of sound through the 
 air is at the rate of about 1125 
 feet per second at the temperature 
 of 62. At the freezing tempera- 
 ture, when the air is denser, it is 
 only 1089f feet per second. The 
 method of determining this velocity 
 is to watch the time that elapses 
 between the flash and the report of 
 a gun fired at the distance of 
 several miles from the observer. 
 As light travels at the rate of 
 nearly 200,000 miles per second, 
 its passage occupies a portion of 
 time too small to be measured iu 
 any terrestrial distance. It may, 
 therefore, be supposed to be seen 
 at the distance of several miles 
 from the observer at the very in- 
 stant of its production. If, there- 
 fore, an observer at -one station 
 begin to count seconds on an accu- 
 rate dial, the moment he sees the 
 flash of a gun at another station, 
 
 435 
 
 say ten miles off, the number of 
 seconds and fractions of a second 
 which elapse between seeing the 
 flash and hearing the report will 
 give a divisor for the number of 
 feet' between the two stations, and 
 the quotient will represent the ve- 
 locity of sound in feet per second. 
 
 All sounds, whatever their in- 
 tensity, whether the noise of a 
 cannon or a whisper, whatever 
 their pitch, whether from the dia- 
 pason organ-pipe or the chirping 
 of a cricket, and whatever their 
 quality, whether the finest music 
 or the most grating noise, all 
 travel with the same amount of 
 speed. 
 
 When sound from any source 
 is propagated in air, waves are 
 formed similar in character to 
 those which may be so beautifully 
 studied when the wind is blowing 
 over a field of standing corn. Now, 
 when it is said that sound travels 
 at the rate of 1125 feet per se- 
 cond, it is not meant that the 
 particles of air move through that 
 distance any more than the ears 
 of corn travel from one end of the 
 field to the other ; it is only the 
 form of the wave which thus tra- 
 vels. So with the particles of 
 air : their individual movement is 
 confined within narrow limits ; but 
 the effect of this movement is pro- 
 pagated from particle to particle 
 with the rapidity of 1125 feet per 
 second, which, although it would 
 be thought very rapid for a motion 
 or the transfer of a body (being 
 about ten times faster than the 
 most violent West India hurri- 
 cane), is yet very slow for the 
 communication or transfer of mo- 
 tion ; for, if we pull or push one 
 end of a solid rod, or the liquid 
 filling a long tube, the other end 
 appears to move at the same in- 
 stant : and although this motion 
 must occupy time (unless the body 
 were perfectly incompressible), it 
 is much more rapid in these cases 
 than in air, which, on account of 
 
sou 
 
 SOUND. 
 
 SOU 
 
 its great compressibility, is one of 
 the slowest conveyers of sound. 
 Every one must have observed that 
 vibration can be diffused through 
 a long mass of metal or wood, so 
 as to be heard at a greater distance 
 than through air ; but in this case, 
 if the sound be loud enough to be 
 audible through the air also, it will 
 be heard twice, first through the 
 solid, and then through the air. 
 Iron conveys sound about 17 times 
 faster than air, wood from 17 to 
 11 times, and water 4 times faster 
 than air. 
 
 When waves of sound meet any 
 fixed surface tolerably smooth, they 
 are reflected according to the law 
 of equal angles of incidence and 
 reflection. In this way echoes are 
 produced. Between two parallel 
 surfaces a loud sound is reflected 
 backwards and forwards, and seve- 
 ral echoes are audible. Six may 
 be heard between Carlton Terrace 
 and the Birdcage Walk, in St. 
 James's Park, London ; fourteen 
 between the steep banks of the 
 Avon at Clifton, and as many 
 under Maidenhead railway bridge. 
 When the parallel surfaces are 
 much nearer together (as the walls 
 of a room), although a large num- 
 ber of echoes are produced, they 
 follow each other too rapidly to be 
 distinguished; and as they reach 
 the ear after equal intervals, they 
 produce a musical note, however 
 unmusical the original noise may 
 have been. Hence all the pheno- 
 mena of reverberation. The pitch 
 of the note depends on the dis- 
 tance between the two walls which 
 cause it, and may be calculated 
 therefrom. 
 
 A noise may also produce a 
 musical echo by being reflected 
 from a large number of equidistant 
 surfaces receding from the ear, so 
 that the sound reflected from each 
 may arrive successively at equal 
 intervals. If we stamp near a 
 long row of palisades, a shrill 
 ringing will be heard. A fine in- 
 
 stance of the same kind is said to 
 occur on the steps of the great 
 Pyramid. If the distance from j 
 edge to edge of each step were 2 
 feet 1 inch, the note produced 
 would be the tenor c, because 
 each echo (having to go and re- 
 turn) would be 4 feet 2 inches 
 later than the previous one, which 
 is the length of the waves of that 
 note. But as the steps gradually 
 diminish in size upwards, the echo, 
 if produced, and heard at the bot- 
 tom, must gradually rise in pitch. 
 
 Sir Isaac Newton discovered a 
 wonderful coincidence which exists 
 between sound and colours, and 
 proves mathematically that the 
 spaces occupied by the colours in 
 the prismatic spectrum correspond 
 with the parts of a musical chord, 
 when it is so divided as to sound 
 the notes of an octave. So this 
 resemblance may now be consi- 
 dered as extending further, for as 
 in mnsic, so likewise in colours, it 
 will be found that harmony con- 
 sists in distance and contrast, not 
 in similitude or approximation. 
 Two notes near each other are 
 grating to the ear, and called dis- 
 cords: in like mariner, two colours 
 very near each other are unpleas- 
 ing to the sight, and may be called 
 discordant. 
 
 The science of acoustics is lit- 
 tle understood, consequently not 
 studied in theory. The want of 
 knowledge of the theory of sound 
 (phonics), in architecture, is a po- 
 sitive evil, and ofttimes of grievous 
 complaint made of our public build- 
 ings, after the expenditure of con- 
 siderable sums of money. Sir John 
 Herschel states, that sounds of all 
 kinds agree in the following par- 
 ticulars: 1. The excitement of a 
 motion in the sounding body. 2. 
 The communication of this motion 
 to the air and other intermedium 
 which is' interposed between the 
 sounding body and our ears. 3. The 
 propagation of such motion from 
 particle to particle of such inter- 
 
sou 
 
 SOUTHWARK BRIDGE. 
 
 SOU 
 
 medium in due succession. 4. Its 
 communication, from the particles 
 of the intermedium adjacent to the 
 ear, to the ear itself. 5. Its convey- 
 ance in the ear, by a certain me- 
 chanism, to the auditory nerves. 
 6. The excitement of sensation. 
 The motion of sound has heen de- 
 monstrated by Chladin on plates 
 of glass and metal, by strewing 
 sand on their surfaces, and observ- 
 ing the forms it assumed when the 
 sound ceased, the sound being pro- 
 duced on the plate by a violin bow. 
 Sound has been used to discover 
 the nature of disease : by the ste- 
 thoscope, an instrument similar to 
 a flute tube, physicians ascertain 
 the state of pulmonary disorders, 
 by applying it to the exterior sur- 
 face of the body covering the 
 lungs. In Chladin's theory, it is 
 stated that rooms will be favour- 
 able to the transmission of sound 
 when arranged to facilitate its na- 
 tural progress, when its intensity 
 is augmented by resonance or si- 
 multaneous reflection, so that the 
 reaction is undistinguishable from 
 the primitive sound, when not too 
 lofty or too vaulted, when there 
 is not a too extensive surface for 
 the sound to strike against at once, 
 when the seats are successively 
 elevated. He observes, that when 
 the enclosed space does not exceed 
 65 feet, any form may be adopted 
 for a room ; that elliptical, circular, 
 and semicircular plans produce 
 prolonged reverberation ; parabolic 
 plans and ceilings are the best for 
 distinct hearing , and that for con- 
 cert-rooms, square and polygonal 
 plans should have pyramidal ceil- 
 ings, and circular plans domed 
 ones, and the orchestra be placed 
 on high, in the centre, to produce 
 the best effect, and avoid echo. 
 Mr. Robert Mills, an American ar- 
 chitect, describes the House of Re- 
 presentatives of the United States 
 Congress as the most elegant le- 
 gislative hall in the world : the 
 plan is a semicircle of 96 feet chord, 
 
 437 
 
 elongated in its diameter line by a 
 parallelogram 72 feet long by 25 
 feet wide : the height to the enta- 
 blature blocking is 35 feet, and to 
 apex of the domed ceiling 57 feet, 
 which is pierced by a circular 
 aperture, crowned by a lantern. 
 Besides additional seats and other 
 improvements, a more important 
 object has been accomplished, 
 namely, rendering the hall a better 
 speaking and hearing room, in 
 which it was before seriously de- 
 ficient. The voice is now com- 
 paratively distinct, and the ear not 
 sensible, except in a few particular 
 points, of any reverberation of the 
 sound -. where the voice before was 
 confused and indistinctly heard, it 
 is now full and clear. 
 
 Sounding-board, a canopy over a pul- 
 pit, intended to diffuse the sound 
 of a preacher's voice through the 
 church. 
 
 Southward bridge, this bridge, design- 
 ed by Mr. John Rennie in 1811, " is 
 admirably suited to the situation, 
 as it will tend to remove the irre- 
 gularity of shallows in this part of 
 the river, by dividing the stream, 
 and thereby directing the current 
 into three regular channels, and 
 consequently removing those sand- 
 banks so injurious to navigation." 
 The bridge is an iron-work of three 
 arches. The middle arch is 240 
 feet span; the other two, 210 feet 
 each. The piers are 24 feet each; 
 whole span of the river about 708 
 feet between the abutments. The 
 abutments are built of stone with 
 dowels introduced into every course 
 of masonry to connect them firmly 
 together, to prevent the possibi- 
 lity of their sliding, and to ena- 
 ble them effectually to resist the 
 laterial thrusts. The foundation 
 for the masonry is formed by grat- 
 ings of strong timber resting upon 
 numerous piles, driven in a slant- 
 ing direction, forming an angle 
 with base of the abutment. The 
 foundations of the piers are from 
 9 to 10 feet below the bed of the 
 
SPA 
 
 SPECIFIC GRAVITY, 
 
 SPE 
 
 river, on a strong flooring of tim- 
 ber resting on numerous })iles, 
 driven perpendicularly ; the courses 
 of masonry are dowelled and laid 
 horizontally. The depth of the 
 foundations were laid thus deep to 
 provide against the deepening of 
 the river should London hridge be 
 rebuilt or altered. The width of 
 the roadway and footways between 
 the parapets is the same as on 
 Blackfriars bridge, 42 feet. 
 
 Spoiling, in mining, breaking up into 
 small pieces for the sake of easily 
 separating the ore from the rock, 
 after which it undergoes the pro- 
 cess of lobbing. 
 
 Span, or chord of an arch, an ima- 
 ginary line extending between its 
 springing on each side. 
 
 Spandril, an irregular triangular space 
 formed between the outer curve or 
 extrados of an arch ; a horizontal 
 line from its apex and a perpendi- 
 cular line from its springing ; also 
 a space on a wall between the outer 
 mouldings of the two arches, and 
 a horizontal line or string-course 
 above them ; likewise between 
 similar mouldings and the line of 
 another arch rising above and en- 
 closing the two. 
 
 Spandril bracketing, a cradling of 
 brackets fixed between one or 
 more curves, each in a vertical 
 plane, and fii the circumference of 
 a circle whose plane is horizontal. 
 
 Spanish and Moorish Architecture. 
 " St. Ferdinand III. of Spain con- 
 quered many places from the 
 Moors, and among others that of 
 Alhamra,t\ie inhabitants of which 
 retreated to Granada, and settled 
 in a quarter of that city, which 
 took the name of their ancient 
 country. This was about 1226. 
 From hence it appears that the 
 name Alhambra, which Swinburne 
 derives from the red colour of the 
 buildings (the Red House), in fact 
 was derived from their country or 
 city ; but where this country or 
 city was I have not discovered, un- 
 less-it be Alhamra in the kingdom 
 
 438 
 
 of Granada, about 60 miles from 
 the south-west of the city. It was 
 in the reign of Mahomet II. that 
 the famous palace of Alhambra was 
 begun. Mahomet began his reign 
 in 1273 and died in 1302." 
 
 Spanish Black is a soft black, pre- 
 pared by burning cork in the man- 
 ner of Frankfort and ivory blacks ; 
 and it differs not essentially from j 
 the former, except in being of a 
 lighter and softer texture. It is 
 subject to the variation of the 
 charred blacks, and eligible for the 
 same uses. 
 
 Spanish Jled'\s an ochre differing lit- 
 tle from Venetian red. 
 
 .S^tf?2s/tacfe,a large bolt driven through 
 the forecastle and forelocked un- 
 der the forecastle-beam, and under 
 and upon the upper deck-beam ; 
 on the forecastle it has a large 
 square ring, for the end of the 
 davit to fix in. 
 
 Spar, a piece of timber employed as 
 a common rafter in a roof. 
 
 Specific Gravity of a body is the 
 relation of its weight, compared 
 with the weight of some other body 
 of the same magnitude. A body 
 immersed in a fluid will sink if its 
 specific gravity be greater than 
 that of the fluid ; but if it be less, 
 the body will rise to the top, and 
 will be only partly uncovered. 
 If the specific gravity of the body 
 and fluid are equal, then the body 
 will remain at rest in any part of 
 the fluid. If the body be heavier 
 than the fluid, it loses as much of 
 its weight when immersed as is 
 equal in weight to a quantity of 
 the fluid of the same bulk. If the 
 specific gravity of the fluid be 
 greater than that of the body, then 
 the quantity of the fluid displaced 
 by the part immersed is equal in 
 weight to the weight of the whole 
 body. Therefore the specific gra- 
 vity of the fluid is to that of the 
 body as the whole magnitude of 
 the body is to the part immersed. 
 The specific gravities of equal so- 
 lids are as their parts immersed in 
 
SPE 
 
 SPIRA. 
 
 SPI 
 
 the same fluid. The specific gra- 
 vities of fluids are as the weights 
 lost by the same immersed body. 
 
 To form a Table of the specific 
 weights of various substances, it is 
 necessary to select one as the stan- 
 dard of comparison: in practice, 
 pure water is always chosen as the 
 starting point for solids and liquids, 
 and pure atmospheric air for gases, 
 the number 1 (TOGO) expressing 
 their specific gravities. The forma- 
 tion of two series is considered to 
 be more convenient than the com- 
 parison to all bodies by one stand- 
 ard, on account of the perplexity of 
 the numbers which would result. 
 
 Solids and Liquids. 
 Water . 
 Platinum 
 Gold 
 Mercury 
 Lead 
 Silver . 
 Copper . 
 Iron, cast . 
 Iron, rod 
 Steel 
 Diamond 
 Rock Crystal . 
 Window-glass . 
 Wax 
 
 Sulphuric acid 
 Oil of Turpentine . 
 Spirit of Wine (strong) 
 Ether . 
 
 1-000 
 
 21-5 
 
 19-5 
 
 13-5 
 
 11-45 
 
 10-5 
 8-96 
 7-2 
 7-7 
 7-8 
 3-5 
 2-6 
 2-52 
 0-964 
 1-84 
 0-865 
 0-83 
 0-72 
 
 Gases. 
 
 Atmospheric air . . I'OOO 
 Oxygen .... M06 
 Hydrogen . . . 0-069 
 Nitrogen . . . 0*972 
 
 Carbonic acid . . . 1'524 
 Carbonic oxide . . 0*967 
 Pit gas .... 0-558 
 Light gas ... 0-985 
 (For the specific gravities of some 
 other substances, see Data, etc.) 
 
 Spend, in mining, to break ground, to 
 work a way. 
 
 Spere, the screen across the lower 
 end of the hall, in domestic build- 
 ings of the middle ages. 
 
 439 
 
 Sperver, the wooden frame at the top 
 of a bed or canopy. 
 
 Sphere, in geometry, a globe, a solid 
 contained under one uniform sur- 
 face, every point of which is equally 
 distant from a point within, called 
 the centre of the sphere, and may 
 be conceived to be generated by 
 the revolution of a semicircle about 
 its diameter, which is fixed, and is 
 called the axis of the sphere. 
 
 Spherical bracketing, the forming of 
 brackets to support lath-and-plas- 
 ter work, so that the surface of the 
 plaster shall form the surface of a 
 sphere. 
 
 Spheroid, a solid body resembling a 
 sphere, supposed to be generated 
 by the revolution of any oval about 
 an axis. 
 
 Spheroidal bracketing, the bracketing 
 prepared for a plaster ceiling whose 
 surface is to form that of a spheroid. 
 
 Spice-plate. At the conclusion of 
 Queen Anne Boleyn's coronation 
 dinner, she took wafers and ipocras. 
 " The table was then taken up, and 
 the Earl of Rutland brought up the 
 surnap, and laid it at the boord's 
 end, and the Queen washed ; she 
 arose and stoode in the middest of 
 the palace hall : to whom the Earl 
 of Sussex, in a goodlie spice-plate, 
 brought a void of spice and cotn- 
 fits." 
 
 Spiceries and pepper-boxes were made 
 very large in the Tudor times, and 
 placed on the high table: their 
 shape was that of a tower, castel- 
 lated and triple-turreted, into 
 which all kinds of spices were 
 placed, of which our ancestors 
 were inordinately fond. 
 
 Spinning-jenny, in mechanics, a ma- 
 chine used in the cotton manufac- 
 tories to turn a great number of 
 spindles, by means of bands from 
 a horizontal wheel. 
 
 Spinning-wheel, the wheel formerly 
 employed in the spinning of mate- 
 rial for textile fabrics : it consisted 
 of a wheel which gave motion to a 
 spindle, on which the thread spun 
 by the fingers was wound. 
 
SPI 
 
 SPRINGS. 
 
 SPR 
 
 Spira (Latin), the base of a colifmn : 
 this member did not exist in the 
 Doric order of architecture, but 
 was always present in the Ionic 
 and Corinthian ; and besides the 
 bases properly belonging to those 
 orders, there was one called the 
 Attic, which may be regarded as a 
 variety of the Ionic. 
 
 Spiral, in .geometry, a curve-line of 
 the circular kind, which in its pro- 
 gress always recedes more and more 
 from its centre. In architecture, a 
 curve that ascends windingabout a 
 cone or spire, so that all its points 
 continually approach its axis. 
 
 Spire, in geometry, a line drawn pro- 
 gressively round the same axis, 
 with a distance between each cir- 
 cle ; a curve-line ; anything contor- 
 ted or wreathed ; a curl, a twist, 
 a wreath. In architecture, it de- 
 notes anything growing up taper ; 
 a round pyramid, a steeple. 
 
 Spirit of wine, or alcohol, is weaker 
 than essential oils, and is so vola- 
 tile as to be of use only as a me- 
 dium for combining oils with resins, 
 etc., as a powerful solvent in the 
 formation of spirit-varnishes, and 
 in some degree as an innocent pro- 
 moter of drying in oils and colours. 
 In picture-cleaning it affords also 
 powerful means of removing var- 
 nishes, etc. 
 
 Spirit-level, a cylindrical glass tube, 
 filled with spirit of wine, except a 
 small bubble of air. In whatever 
 position the tube may be placed, 
 the bubble of air will always tend 
 to the highest part of it ; but when 
 placed in a perfectly horizontal po- 
 sition, the bubble will remain sta- 
 tionary at the centre of the tube. 
 
 Spirketiny, the strake wrought on the 
 ends of the beams of a ship ; where 
 there are ports, it is the two strakes 
 worked up to the port-cells; in 
 which case the middle of the planks 
 should not be reduced, unless it 
 occasions the butts to be less than 
 6 inches. 
 
 Spital, a hospital. 
 
 Splashers, screws or guards placed 
 
 over locomotive-engine wheels (u- 
 sually faced with brass), to prevent 
 any person on the engine coming 
 in contact with the wheels, and 
 also to protect the machinery from 
 any wet or dirt thrown up by the 
 wheels. 
 
 Splay, the slanting or bevelled expan- 
 sion groin, in Gothic and Domes- 
 tic architecture, to doors, windows, 
 and openings in walls, etc. 
 
 Split-pins and cotters, round and flat 
 pins, with a head at one end, and 
 split at the other end. They are 
 used through the ends of bolts, 
 to keep them from getting out of 
 their place, the split end being 
 opened like the letter K!, to keep 
 the pin or cotter from falling out. 
 
 Spoons. In eating, spoons seem to 
 have been almost the only aid to 
 the fingers at a very early period of 
 our history. " Knives (ancient as 
 they are) were first made in Eng- 
 land in 15G3, by Thomas Mathews, 
 on Fleet Bridge, London," and 
 were therefore only obtainable, in 
 any considerable number, before 
 that time, by the upper classes of 
 society. Horn and wood were the 
 materials of which spoons were 
 made down to Elizabeth's reign, 
 when pewter became common, and 
 was much improved. 
 
 Spray, in navigation, the sprinkling 
 of the sea driven from the top of 
 a high wave in stormy weather. 
 
 Spring, in mechanics, an elastic body, 
 which, when distorted or com- 
 pressed, has the power of restoring 
 itself ; any active power by which 
 motion is produced or propagated. 
 
 Spring, in navigation, a rope passed 
 out at one extremity of a ship, and 
 attached to a cable from the other, 
 to bring her broadside to bear upon 
 an object. 
 
 Springs, in locomotive engines, the 
 elastic steel supporters of the boiler 
 and frame upon the axles, named 
 after the particular parts to which 
 they apply ; as leading-springs for 
 the leading-axle, driving-springs 
 for the driving-axle,trailing-springs 
 
SPR 
 
 SPRINGS. 
 
 SPR 
 
 for the trailing-axle.tender-springs, 
 drag-springs, buffer-springs, piston- 
 springs, valve-springs, etc., all pro- 
 portioned to the particular duty 
 they have to perform. 
 Springs. Water-springs, top-springs, 
 springs of the deep, etc. In con- 
 templating the origin and utility of 
 \vater-springs,as dispersed upon the 
 face of the earth, for the use of man 
 and beast, and as far deep in the 
 earth as the miner's art has led, 
 we find much both to inform and 
 amuse those who have not made 
 this subject their study. All springs 
 take their source from the seas, 
 lakes, and rivers : by the heat from 
 that great luminary of our earth, 
 the sun, they are evaporated into 
 the upper regions, and there rare- 
 fied, forming clouds filled with rain, 
 which, by attraction and different 
 causes, is plentifully showered upon 
 the earth. It has been urged by 
 some, that it is impossible for rain 
 to supply the copious springs that 
 arise in stony countries, where 
 there is little appearance of a re- 
 ceiving soil, and that rocky ground 
 is impervious to them. But it must 
 be admitted, that if rocks make a 
 discharge of water, they are also 
 capable of receiving it ; and that 
 rocky countries are generally as 
 well supplied with springs as 
 others, is well known to all travel- 
 lers. One of the most stony coun- 
 tries in Europe is Norway, where 
 there is an abundant supply of pure 
 water. It has also been stated that 
 those places where it never rains, 
 both in Africa and some parts of 
 America, are yet well supplied with 
 springs, and at times have flooded 
 rivers. Whence come their springs ? 
 The Nile, Niger, etc., are rivers of 
 magnitude, and drain the greatest 
 part of Africa. They are seldom 
 replenished with rain ; but they 
 receive their immense floods from 
 the extensive mountainous country 
 lying above and behind them, 
 where they have all kinds of 
 weather ; and some of the hills are 
 
 annually covered with snow, as 
 well as those districts in America 
 where it seldom rains: but the 
 dews are very prolific, so much so 
 that on walking out in the evening 
 or early in the morning, amongst 
 the herbage, it is nearly the same 
 as in this country after a shower of 
 rain. Hence it may be fairly pre- 
 sumed, that the springs of those 
 countries are fed by the excessive 
 dews, similar to rain in other parts 
 of the world, drawn from seas, 
 lakes, and rivers, from the exhala- 
 tions by the sun during the heat 
 of the day. In those tropical cli- 
 mates, night and day are nearly 
 equally divided. Nature is thus 
 perfect in all her works, by allow- 
 ing a sufficient period for the de- 
 scent of dews to supply the place 
 of rain. 
 
 It has been also asserted, that 
 the principal springs come from 
 the sea, and ascend their different 
 chasms in the lower parts of the 
 earth connected with it ; that the 
 water is then forced in, divested of 
 its saltness, and made fresh by per- 
 colation through the sand or silt in 
 those chasms. It then becomes, 
 the lighter fluid. The superior 
 gravity of the salt then causes it 
 to rise to the height of the highest 
 hills. This hypothesis has proved 
 to be unsound. The water of salt 
 springs, from which so large a por- 
 tion of salt is made, by evaporation, 
 pumped up from the coal-pits at 
 Butley, in Durham, and at Newcas- 
 tle, is not sea-water, but is of a 
 redder colour, and contains a far 
 larger portion of natron. But 
 what is still a greater proof that 
 those salt-springs have no connec- 
 tion with the sea, is, that in the 
 middle of the river Wear, between 
 Durham and Bishop's Auckland, 
 during the droughty months of 
 summer, when the waters are low, 
 from a rock bottom arises one of 
 the finest salt-water springs known, 
 many degrees salter than that of 
 the sea, surrounded by copious 
 
SPR 
 
 STADIUM. 
 
 STA 
 
 streams of fresh-water ; and this 
 place is between 200 and 300 feet 
 ahove the level of the sea. What 
 siphon-like power could force it to 
 this altitude, so far within the land, 
 from that fancied source? All these 
 kind of springs receive their salt- 
 ness from passing through beds or 
 mines of salt, such as those at the 
 Wicke, in Cheshire, etc., or some 
 matter yet unknown, of a less 
 dense body, that will more easily 
 communicate its salter particles to 
 the water running through it. 
 What say the inspired writers? 
 " There is a multitude of waters in 
 the heavens ;" and " He causes the 
 vapours to ascend from the ends 
 of the earth :" " He makes the 
 rain." That is from its seas, its 
 lakes, and rivers, by natural exhala- 
 tions, the clouds are replenished. 
 " He bindeth up the waters in his 
 thick clouds ; and the cloud is not 
 rent under them." " Who hath 
 divided a watercourse for the over- 
 flowing of its waters, to cause it to 
 rain on the earth ?" The vapours 
 which arise from the sea are much 
 more than sufficient to supply both 
 the surface of the earth and the 
 rivers with water ; whilst the 
 mountains,by their particular struc- 
 ture and formation, attract and, as 
 it were, arrest the vapours and the 
 rain that fluctuate about in the at- 
 mpsphere ; and having collected 
 them in their reservoirs, dismiss 
 them again through their sides, 
 either in perpetual or intermitting 
 currents. 
 
 Spring -balance, in locomotive engines, 
 a spiral spring weighing-balance, 
 with an index and pointer. This 
 is attached to the end of the lever, 
 by which the pressure upon the 
 safety-valve is adjusted. 
 
 Spring-hooks, in locomotive engines, 
 the hooks fixing the driving-wheel 
 spring to the frame. A screw on 
 the end of the hook regulates the 
 weight on the driving wheels. 
 
 Spring-pins, in locomotive engines, 
 iron rods fitted between the springs 
 
 and the axle-boxes, to sustain and 
 regulate the pressure of the axles. 
 
 Springing, the bottom stone of an 
 arch which lies upon the impost. 
 
 Sprit, in navigation, a small boom or 
 pole which crosses the sail of a 
 vessel diagonally from the mast to 
 the hindermost corner of the sail, 
 to elevate and extend it. 
 
 Spritsail, in navigation, the sail that 
 belongs to the bowsprit. 
 
 Sprung, in navigation. W r hen a top- 
 mast is broken or cracked near the 
 cap, it is said to be sprung. 
 
 Spurs, pieces of timber fixed on the 
 bulgeways, and the upper end 
 bolted to the ship's side above 
 water, for security to the bulge- 
 ways. 
 
 Square, in geometry, a quadrilateral 
 figure with right angles and equal 
 sides. In architecture, an area of 
 four sides, with houses on each side. 
 
 Square-rigged, in navigation, an epi- 
 thet applied to a ship that has long 
 yards at right angles with the 
 length of the deck, in contradis- 
 tinction to sails extended obliquely 
 by stays or lateen yards. 
 
 Square sails are such as are extended 
 by a yard, distinguished from others 
 extended by booms, stays, lateens, 
 and gaffs. 
 
 Square tuck, when the planks of the 
 bottom are not worked round to 
 the wing transom, but end at the 
 fashion-piece. 
 
 Squaring the circle, in mathematics, 
 is attempting to make a square that 
 shall be equal to a given circle. 
 
 Squinch,*. term applied to small arches 
 or projecting courses of stone form- 
 ed across the angles of towers. 
 
 Squint, an opening through the wall 
 of a Roman Catholic church, in an 
 oblique direction, for the purpose 
 of enabling persons in the transept 
 or aisle to see the elevation of the 
 Host at the high altar. 
 Stadium, a Roman measure of length, 
 nearly equivalent to our furlong. 
 The term was also applied to a 
 building, or an enclosed area, in j 
 which gymnastic and athletic ex- 
 
STA 
 
 STAIRCASE. 
 
 STA 
 
 ercises, chariot-racing, and foot- 
 racing, wrestling, and other public 
 games, were exhibited. The sta- 
 dium was divided into distances for 
 the racers. Also a Greek structure, 
 of an oblong area, terminated at 
 one end by a straight line, at the 
 other by a semicircle, having the 
 breadth of the stadium for its base. 
 Around this area were ranges of 
 seats rising one above another, 
 erected for the purpose of witness- 
 ing the public sports at Olympia 
 and other places 
 
 Staircases. It was in the reign of 
 Elizabeth that staircases first be- 
 came features in English houses. 
 Hand-rails and balustrades, unlike 
 the rickety contrivances of modern 
 days, were of gigantic proportions, 
 and presented at once a bold, pic- 
 turesque, and secure appearance ; 
 yet so variously and fancifully de- 
 corated, that their effect was always 
 pleasing and free from clumsiness. 
 In the middle of Verulam House 
 was a delicate staircase of wood, 
 which was curiously carved; and 
 on the posts of every interstice was 
 fixed some figure, as a grave divine 
 with his book and spectacles, a 
 mendicant friar, etc. In two of 
 the principal chambers of Wressil 
 Castle are small beautiful staircases, 
 with octagon screens, embattled at 
 the top, and covered with very bold 
 sculpture, containing double flights 
 of stairs, winding round each other, 
 after the design of Palladio. The 
 east stairs at Wimbledon House 
 lead from the marble parlour to the 
 great gallery and the dining-room, 
 and are richly adorned with wain- 
 scot of oak round the outsides 
 thereof, all well gilt with fillets and 
 stars of gold. The steps of these 
 stairs were in number 33, and 6 feet 
 6 inches long, adorned with 5-foot 
 paces, all varnished black and white, 
 and chequer-work ; the highest of 
 which foot-pace is a very large one, 
 and benched with a wainscot bench, 
 all garnished with gold. 
 
 Staircases, in ordinary modern 
 
 practice, should be light, spacious, 
 and easy, seeming to invite people 
 to ascend. Principal staircases 
 should not be narrower than 4 feet, 
 so that if two persons meet thereon, 
 they may pass each other with con- 
 venience; but they may be extended 
 in breadth to 10 or 12 feet, accord- 
 ing to the importance of the build- 
 ing. The steps should never ex- 
 ceed 6 inches in height, nor be less 
 than 4 inches ; but this latter height 
 is only allowable in very wide stair- 
 cases. The breadth, or the flat 
 horizontal part, which is called the 
 tread of the step, should not be less 
 than a foot, nor exceed 15 inches. 
 
 Stakes, in ship-building, are the regu- 
 lar ranges of planks on the bottom 
 and the sides of the ship, reaching 
 from the stem to the stern. 
 
 Stall, a place occupied by a monk, 
 canon, dean, or prebendary, in the 
 choir of a church ; sometimes ap- 
 plied also to the sedilia or pres- 
 byteries for the officiating ministers 
 in the wall of a chancel. 
 
 Stamps, machinery for crushing ores. 
 
 Stanchion, in ship-building, a small 
 pillar of wood or iron, used to prop 
 and support the decks, awning, etc. 
 
 Stanchion, the upright iron bar be- 
 tween the mullions of a window, 
 screen, etc. 
 
 Standards, timbers in the form of 
 knees, with one arm on the deck, 
 and the other fayed to a ship's side. 
 
 Stantients, the upright pieces in a 
 bulk-head, breast-work, etc., of a 
 ship. 
 
 Starboard, in navigation, the right- 
 hand side of a ship, looking for- 
 ward, as larboard is the left-hand. 
 
 Starlings, in architecture, are large 
 piles placed on the outside of the 
 foundation of the piers of bridges, 
 to break the force of the water and 
 protect the stone-work. 
 
 Statics, the science which considers 
 the weight of bodies, or the motion 
 of bodies arising from gravity. 
 
 Stations, a generic term applied to 
 fixed points or places, of which a 
 series is included in any extended 
 
STA 
 
 STATIONS. 
 
 STA 
 
 works or arrangements. Thus we 
 have Post-office Stations, Telegraph 
 Stations,PoliceStations,Fire-engine 
 Stations, and Railway Stations. 
 
 As applied to railways, the term 
 station is a very comprehensive one, 
 comprising a multitude of buildings 
 and apparatus of an extended and 
 costly character. Terminal stations 
 of long lines of railway usually 
 cover several acres of ground, and 
 include buildings for the assem- 
 bling of the passengers, and for 
 classifying them in separate com- 
 partments, according to the class 
 of carriage they intend to occupy ; 
 extended platforms, conveniently 
 arranged for the arrival and de- 
 parture of the trains, and well 
 protected from the weather, and 
 lighted by night. The level of 
 these platforms is arranged so that 
 persons walk directly into the car- 
 riages, without ascent or descent, 
 and their length is sufficient to 
 serve many carriages, or two or 
 more entire trains at one and the 
 same time. A separate department 
 of the station is usually allotted to 
 the receipt, arrangement, and dis- 
 tribution of parcels and goods of 
 all kinds, from bulky bales and 
 ponderous hogsheads down to a 
 packet of such insignificant dimen- 
 sions that it may hold no more than 
 a half-ounce letter. The goods 
 warehouses belonging to this de- 
 partment are of great size, and fully 
 furnished with cranes and moving 
 and weighing gear of all requisite 
 powers and dimensions, fitted to 
 load and unload the goods-wag- 
 gons belonging to the line, and all 
 ordinary road vehicles. Besides 
 these purposes, the terminal and 
 first-class stations often include a 
 completeengineering establishment 
 of a practical character, in which 
 the locomotive engines, carriages, 
 trucks, waggons, etc., are repaired 
 and built, and including foundry, 
 smithies, pattern-turning, fitting, 
 erecting, and repairing shops ; the 
 latter being provided with rails 
 
 below for running the engines into 
 the building, and travelling cranes 
 above for lifting them entire when 
 needed, or aiding in their dissection! 
 with all the rapidity and delicacy of 
 movement which commonly belong' 
 only to operations upon far smaller I 
 and easier handled subjects. The! 
 station also embraces ample build- 
 ings or engine-houses, in which the 
 locomotive engines are ranged like 
 so many post-horses in a road-side 
 stable, ready for immediate action, 
 and in which the raking out of fires 
 and the cleaning and adjustment! 
 are daily performed. Complete ar-j 
 rangements are also included for^ 
 delivering water and coke to thej 
 tenders, and in some the necessary 
 buildings and apparatus are com- 
 prised for pumping the water from 
 deep wells, for burning the coke, 
 and even for manufacturing the gas 
 to be employed in the lighting of 
 the whole of the buildings and 
 shops. Board-rooms, clerks'-rooms 
 and offices, and residences for the 
 station-master and assistants, be- 
 sides store-rooms of all kinds, re- 
 freshment-saloons, urinals, water- 
 closets, police - rooms, telegraph- 
 rooms, lost-luggage office, etc., etc., 
 are also among the necessary de- 
 tails of a principal railway station. 
 The area of the station is covered, 
 with lines of railway for the pas- 
 sage of the engines and carriages, 
 and provided with turn-tables, re- 
 volving and traversing, for readily 
 transferring the carriages from one ; 
 line to another, besides switches 
 and apparatus for connecting the 
 several lines at intervals. Of the 
 extent of some of these works at 
 one of the metropolitan stations, 
 that of Camden Town, on the line 
 of the North-western Railway, the 
 following particulars will convey 
 some idea: This station, which is 
 chiefly for goods only, covers an 
 area of 30 acres, and has a length 
 of double line of 2500 feet for the 
 goods waggons only, and entirely 
 clear of the main line. The length 
 
STA 
 
 STEAM ENGINE. 
 
 STE 
 
 of single line of railway, exclusive 
 of the main line, exceeds 12 miles. 
 There are 112 sets of points for 
 turning carnages from one line to 
 another, 196 turn-plates, and 110 
 cranes, varying in power from 1J 
 to 20 tons. The area covered with 
 goods' sheds exceeds 135,000 su- 
 perficial feet, and that of the plat- 
 form is 30,000 feet. The circular 
 engine-house is 160 feet in diame- 
 ter, and will contain 24 engines 
 and tenders ; the central turn-table 
 within it is 41 feet in diameter. 
 The annual consumption of gas 
 exceeds six millions of cubic feet. 
 In minor or intermediate sta- 
 tions, the works are, of course, of 
 smaller magnitude, and are not 
 required to subserve all the com- 
 bined purposes of a principal sta- 
 tion. 
 
 Statuary, a carver of images or re- 
 presentations of life; one who 
 practises or professes the art of 
 sculpture. 
 
 Staves, in joinery, the boards that are 
 joined together laterally, in order 
 to form a hollow cylinder, cylin- 
 droid, cone, or conoid, or any frus- 
 tum of these bodies. The shafts 
 of columns, in joinery, are fre- 
 quently glued up in staves. 
 
 Stay, in navigation, a strong rope 
 employed to support the mast in the 
 fore-part : to stay a ship, to manage 
 the sails so that she shall not make 
 any way forward, preparatory to 
 her tacking about. 
 
 Staysail, in navigation, a sort of tri- 
 angular sail extended on a stay. 
 
 Stays, outside, in locomotive engines, 
 sling-stays binding the boiler and 
 frame together. 
 
 Stays, inside boiler, in locomotive 
 steam-engines, rods of iron binding 
 together the flat ends of the boilers. 
 The flat side of the dome is like- 
 wise strongly bound together by 
 iron rods. Without these stays, 
 they could not resist the pressure 
 of the steam against so large a 
 surface. 
 
 Stays, inside frame, in locomotive 
 
 engines, strong stays placed below 
 the boiler, firmly fixed at one end 
 to the fire-box, and at the other 
 end to the smoke-box : they sup- j 
 port the inside bearings of the 
 driving axle and other parts of the 
 machinery. 
 
 Stay-wedges, in locomotive engines, 
 wedges fitted to the inside bearings 
 of the driving axles, to keep them 
 in their proper position in the stays. 
 
 Steam, the vapour of hot water at the 
 boiling point of 212 degrees. 
 
 Steam-chest, in locomotive engines, 
 a box attached to the cylinders, 
 into which the steam is admitted 
 by the regulator: the slide-valve 
 works in this box over the steam- 
 ports, which open into it from the 
 cylinder. 
 
 Steam-chest cocks, in locomotive en- 
 gines, oil-cups, placed conveniently 
 for lubricating the faces of the 
 steam-ports and slide-valve. 
 
 Steam compression. The steam which 
 has performed its duty in the cy- 
 linder, but which has not escaped 
 before the slide-valve closes the 
 exhaust-port, is compressed by the 
 advancing piston. This compres- 
 sion begins, according to the lap 
 and travel of the slide, from 2 to 3 
 inches from the end of the stroke, 
 and is of considerable amount. It 
 is, however, of advantage in check- 
 ing the momentum of the piston, 
 and relieving the strain on the con- 
 necting and piston rods at the end 
 of each stroke, and is not therefore 
 all lost power. 
 
 Steam Engine, a machine for deriving 
 power from the expansion which 
 results from the conversion of water 
 into vapour or steam by the appli- 
 cation of heat. This expansion is 
 so great that a given quantity of 
 water becomes, when changed into 
 the form of steam, enlarged to about 
 1,728 times its original bulk; and 
 this expansion takes place with a 
 force that may be termed irresis- 
 tible. Thus if water be enclosed 
 in a vessel, say of iron or any other 
 strong material, and the water be 
 
STE 
 
 STEAM ENGINE. 
 
 STE 
 
 expanded into steam, and insuffi- 
 cient space left for the expansion, 
 the vessel will be hurst hy the force 
 of the steam within. A steam en- 
 gine consists essentially of a vessel 
 into which the steam is admitted, 
 and which is provided with a mov- 
 able disc, closely fitting the interior 
 and capable of sliding within the 
 vessel. This vessel is made cylin- 
 drical, because this form gives the 
 greatest strength and is the most 
 readily fitted with the movable 
 disc. The vessel is termed the 
 cylinder, and the disc the piston. 
 Supposing the cylinder to be placed 
 upright, and fitted with a close co- 
 ver, and that while the piston is 
 near the bottom of it steam is ad- 
 mitted to rush in through a pipe 
 below the piston, the piston will 
 be driven up by the steam, and if, 
 when it reaches the upper part of 
 the cylinder, the steam from below 
 is shut off, and admitted through 
 an upper pipe to press upon the 
 top surface of the piston, it will be 
 forced down again. Thus a rectili- 
 near motion up and down is pro- 
 duced, and this constitutes what is 
 called the principle of the steam 
 engine. All its other parts are for 
 the purpose of regulating the ad- 
 mission of the steam, and convert- 
 ing the rectilinear motion produced 
 at the cylinder into a rotary motion 
 at the point where the power is 
 required to be applied for working 
 machinery. The steam, when no 
 longer required for that purpose, is 
 allowed to escape into the open at- 
 mosphere, or conducted in a pipe to 
 another vessel, which, being cooled 
 by the application of cold water, 
 rapidly condenses the steam, that is, 
 reconverts it into water. If per- 
 mitted to escape irito the air, the 
 steam has to force itself against the 
 pressure of the atmosphere, whereas 
 if conducted into a condenser, this 
 force is not required. Hence steam 
 of less pressure will work what is 
 termed a low-pressure or condensing 
 engine, while that already described 
 
 446 
 
 is for distinction called a high-pres- 
 sure engine. A third variety of 
 steam engine is worked by shutting 
 off the steam before it has driven 
 the piston the whole length of the 
 cylinder, or completed the stroke, 
 as it is termed, and the subsequent 
 expansion of the steam completes 
 the impulse upon the piston. En- 
 gines thus worked are distinguished 
 as expansive engines. The princi- 
 pal difference in the mechanism of 
 condensing and expansive steam 
 engines is in the movement of the 
 apparatus which admits and shuts 
 off the steam, or the valves, which 
 act as doors within the pipes. The 
 several parts of a condensing engine 
 and its appliances are as follows : 
 1st, the boiler, in which the steam 
 is produced from water by the ac- 
 tion of fire in the furnace beneath ; 
 2ndly, the steam-pipe, in which the 
 steam is conveyed to the engine : 
 Srdly, the steam-chests, in which 
 the steam is received, and which 
 communicates with the two induc- 
 tion-pipes that lead into the upper 
 and lower part of the cylinder; 
 4thly, the cylinder fitted with thp 
 piston, and having pipes carted the 
 eduction-pipes, through which the 
 steam passes away when its work 
 in the cylinder is completed, into 
 1 the condenser; 5thly, the air-pump, 
 which abstracts the water formed 
 by the condensed steam, sending 
 it into the boiler, producing a par- 
 tial vacuum within the condenser, 
 and thus assisting the escape of the 
 steam from the cylinder; 6thly, 
 the condenser itself, which is kept 
 cool with water pumped up by the 
 cold-water pump. The piston has a 
 rod fixed to it, which works through 
 a steam-tight opening or stuffing- 
 box in the lid of the cylinder, and 
 this piston-rod is attached to one 
 end of a beam, which turns upon a 
 centre, and the other end of which 
 works a connecting-rod attached to 
 a crank, to the side of which a ro- 
 tary motion is thus imparted. In 
 some engines the piston-rod is con- 
 
STE 
 
 STEAM NAVIGATION. 
 
 STE 
 
 nected by links directly with the 
 crank, and these are hence termed 
 direct-action steam engines, while 
 the former are distinguished as 
 beam-engines. In others, again, the 
 piston-rod is attached to the crank 
 without links, and the cylinder, 
 instead of being fixed, is made to 
 vibrate or oscillate: these are there- 
 fore termed vibrating or oscillating 
 engines. Marine engines for pro- 
 pelling vessels on the water, and 
 locomotive engines for propelling 
 trains of carriages upon railways, 
 are each distinguished by pecu- 
 liarities of construction and ar- 
 rangements, fitting them for their 
 especial duties. 
 
 Steam exhaust-port, in the locomo- 
 tive engine, the passage opened be- 
 low the slide-valve from the cylin- 
 der to the atmosphere. It is 
 placed between the two steam - 
 ports, and is nearly twice their 
 area, the more freely to permit the 
 escape of the steam. It is open 
 to the blast-pipe, and is cut off 
 from any communication with the 
 steam in the steam-chest by the 
 slide-valves. The arch part of the 
 slide-valve opens the passage from 
 the cylinder into the central ex- 
 haust-port, where, through the 
 blast-pipe and chimney, it escapes 
 to the atmosphere, and by this 
 means produces the draught on the 
 fire. 
 
 Steam-gauge, a contrivance to show 
 the exact amount of pressure of 
 the steam; it consists of a siphon- 
 tube with equal legs, half-filled 
 with mercury : one end is cemen- 
 ted into a pipe which enters that 
 part of the boiler which contains 
 the steam ; the other end is open 
 to the atmosphere. A stop-cock 
 is usually provided between this 
 gauge and the boiler, so that it 
 may be put in communication with 
 the boiler at pleasure. When the 
 stop-cock is open, the steam acting 
 on the mercury in one leg of the 
 gauge presses it down, and the 
 mercury in the other leg rises. The 
 
 difference between the twocolumns 
 is the height of mercury which cor- 
 responds to the excess of the pres- 
 sure of the steam in the boiler 
 above the pressure of the atmo- 
 sphere ; or, in other words, to 
 the effective pressure on the safety- 
 valve. If half a pound per inch be 
 allowed for the length of this 
 column, the effective pressure of 
 the steam, in pounds per square 
 inch, is obtained. 
 
 Steam Navigation. This is accom- 
 plished by the application of steam 
 power to the marine engine, by 
 which vessels of all dimensions are 
 propelled on the waters of the 
 ocean or on the principal rivers. 
 Whether by means of the paddle- 
 wheel, or by the spiral or helix 
 screw, the fluid is displaced and 
 the vessel sent forward at the vari- 
 ous speeds consequent upon the 
 skill employed in the making of 
 vessel and engine. Much compe- 
 tition and many controversies have 
 existed upon the best methods to 
 be adopted. Many instances of 
 failures have occurred from the 
 simple circumstance of the builder 
 of the ship and the constructor of 
 the engine not acting in concert. 
 Steam vessels for river passenger- 
 traffic, when in trim and all their 
 parts well constructed, average a 
 speed of 15 miles an hour ; in Ame- 
 rica 18 miles; and sea-going ves- 
 sels average on their way 12 miles. 
 Cunard's packet from Liverpool to 
 Halifax and Boston have done more. 
 The West India and the Peninsular 
 and OrientalCompanies have splen- 
 did vessels, which do credit to the 
 companies for their enterprise, to 
 the builders for the construction of 
 the craft, and to the engineers for 
 the construction of the engines. 
 Other companies exist who deserve 
 their proportion of praise. It is to 
 England and Scotland that the 
 world is indebted for this new ele- 
 ment of civilization. 
 
 Steam-pipes, in locomotive engines, 
 the pipes which collect and con- 
 
STE 
 
 STEAM-WHISTLE. 
 
 STE 
 
 vey the steam to the steam-ctiest : 
 they commence inside the boiler. 
 In boilers with domes, the receiv- 
 ing pipe is raised as high as possi- 
 ble, and turned back round the 
 edges of the open end, to prevent 
 any water which might rise so high 
 from overlying the pipe. In boilers 
 having no domes, the steam is col- 
 lected in a horizontal pipe pierced 
 with numerous small holes. After 
 being collected, the steam-pipes are 
 continued outside the boiler to the 
 steam-chest. The internal dia- 
 meter of the steam-pipe is usually 
 rather more than one-fifth of the 
 diameter of the steam cylinders : 
 the area of the passages through 
 valves, in some of Watt's beam-en- 
 gines, is nearly one square inch per 
 horse power. This is in some cases 
 too large for steam-passages, but 
 rather too small for the exhausting 
 valve-passages. 
 
 Steam-pipe for tender,in locomotives, 
 a small pipe attached to the boiler 
 by a cock, for admitting the spare 
 steam to heat the water in the ten- 
 der. 
 
 Steam-ports, in locomotive engines, 
 two passages from the steam-chest 
 to the cylinder. The steam is ad- 
 mitted to and from these passages 
 by the slide-valve opening the port 
 for the admission of steam to the 
 cylinder, and then by shutting off 
 this port from the steam in the 
 steam-chest, and, opening the same 
 passage by which it entered, it is 
 conveyed to the atmosphere. 
 
 Steam-whistle, an apparatus attached 
 to the boiler of a locomotive engine 
 for the purpose of giving warning 
 of its approach when running. The 
 construction of the whistle is shown 
 to one-quarter size in the annexed 
 engravings. It is made of brass, 
 and the foot, A, is cast hollow with 
 a flange, B, at the bottom to bolt 
 it on the fire-box : it has a cock, c, 
 placed in it, with the handle D, and 
 screw E, to keep it tight; the han- 
 dle projects out, to allow firm hold 
 to be taken of it. The cup F is 
 
 448 
 
 fixed upon the foot A, by screwing 
 the piece G upon it, and both are 
 turned truly at their outer edges, 
 leaving a very narrow passage, i i, 
 four inches diameter,between them 
 all round. The piece G is hollow, 
 having holes, H, in its sides ; and a 
 
STE 
 
 STEEL. 
 
 STE 
 
 pillar, K, stands upon its centre, on 
 which is screwed the hell, L, L, the 
 thin edge of which is brought just 
 over the opening i, and half an 
 inch above it. 
 
 When the cock is opened, the 
 steam enters the cupr through the 
 holes H, and rushes out at the nar- 
 row slit i, striking the thin edge 
 of the bell, L, in a manner similar 
 to the action in organ-pipes, and 
 producing an exceedingly shrill and 
 piercing sound. Some" holes, M, 
 are made in the top of the bell, to 
 allow the steam to pass through, 
 which improves the sound consi- 
 derably. The size of the concentric 
 part where the steam escapes, and 
 the depth of the bell part, and 
 their distance asunder, regulate the 
 tones of the whistle, from a shrill 
 treble to a deep bass. The cock 
 should be steadily opened, to adjust 
 the quantity of steam, so as to pro- 
 duce the clearest sound. The steam 
 whistle is very effective, and its 
 sound can be heard at a great dis- 
 tance. 
 
 Steel is composed chiefly of iron and 
 carbon ; yet these alone will pro- 
 duce but a poor and brittle article. 
 Good steel contains a variety of 
 elements, almost all of those, in 
 fact, which are considered impuri- 
 ties of iron when present in ex- 
 cess. 
 
 Steel is divided into four distinct 
 classes. Damascus steel ; German 
 steel ; Blistered, or blister steel, to 
 which class shear steel belongs ; 
 and Cast steel. The first is made 
 directly from the ore, or by weld- 
 ing steel rods and iron rods toge- 
 ther ; the second from pig metal, 
 by depriving the latter of a portion 
 of its carbon and impurities ; the 
 third from bar iron, by impregnat- 
 ing it with carbon ; and the fourth 
 class, or cast steel, may be made 
 from either of the others, by melt- 
 ing it in a crucible. Still, blistered 
 steel appears to be the most ad- 
 vantageous, so far as quality is con- 
 cerned. 
 
 449 
 
 Damascus Steel. 
 
 This steel derives its name from 
 Damascus, a city in Asia. The 
 swords or scimitars of Damascus 
 present upon their surface a watery 
 appearance, and variegation of 
 streaks of a silvery white, black, 
 and grey colour, and fine and coarse 
 lines, exhibiting regular and irre- 
 gular figures. The excellent quality 
 of these blades is proverbial : they 
 unite hardness to great elasticity. 
 Genuine Damascus steel is made 
 directly from iron ore ; and meagre 
 as our knowledge is concerning the 
 subsequent manipulations, such as 
 forging and hardening, it is known 
 that the steel is smelted, in a kind 
 of Catalan forge, from red oxide of 
 iron, a red clay ore found in transi- 
 tion slate. It is generally believed 
 that the great strength of this steel 
 is to be attributed to a small quan- 
 tity of aluminum which enters into 
 its composition, and which is de- 
 rived from the clay of the ore, - 
 an opinion which has this fact in 
 its favour, that no material imparts 
 a greater degree of tenacity to iron 
 than alumina. Great exertions have 
 been made to imitate this steel, in 
 which, of all nations, the French 
 have been the most successful. 
 They have succeeded in imitating 
 not only irregular figures, but ara- 
 besques and initials, in the most 
 beautiful manner. Still, the French 
 is far less tenacious and hard than 
 the genuine Damascus steel. The 
 virtue of the latter, therefore, must 
 be sought for in the ore from which 
 it is made. 
 
 German Steel. 
 
 This steel is made in two different 
 ways, either directly from the ore 
 or by converting the ore into pig- 
 metal, and then into steel. The 
 steel manufactured by the first me- 
 thod is generally crude and irregu- 
 lar, and therefore this method is 
 seldom practised. 
 
 The Stuck oven, orWulfs oven, 
 
STE 
 
 STEEL, GERMAN. 
 
 SEW 
 
 as well as the Catalan forge, is one 
 of the furnaces employed iu the 
 manufacture of steel from ore. In 
 making steel, the hlast is directed 
 more upon the fuel than upon the 
 iron : the tuyere is level : the iron 
 is impregnated with carbon. The 
 reverse is the case in the manufac- 
 ture of iron. In the blue-oven, a 
 kind of pig metal is frequently 
 made, which is almost pure steel ; 
 but it is coarse, and never, even 
 after the best refining, makes a 
 good article. All manipulations, 
 the object of which is to make steel 
 directly from the ore, are unpro- 
 fitable. 
 
 To this class belongs the manu- 
 facture of wootz, or East Indian 
 steel. This is certainly a good 
 steel, and is partially imitated in 
 America. Wootz is smelted di- 
 rectly from the ore, which is the 
 black magnetic oxide of iron, in 
 furnaces five or six feet in height, of 
 the form of some foundry cupolas. 
 Previously to smelting, the ore is 
 finely pounded and washed, to re- 
 move impurities. 
 
 The n*;mufaeture of steel from 
 pig metal does not depend so much 
 upon the manipulations in the forge 
 as upon the quality of the metal. 
 The ores generally employed are 
 the crystallized carbonate, spathic 
 ore, often mixed in a slight degree 
 with hematite, and the rich red 
 peroxides. Magnetic ores do not 
 answer for such work, and are 
 therefore but seldom used. The 
 same may be said in relation to the 
 hydrated oxides. Pig metal for 
 steel manufacture is smelted with 
 as little lime or other flux as possi- 
 ble. The principal flux to be re- 
 lied on is manganese ; but this al- 
 ways exists in the ore, and is never 
 used as an artificial admixture, 
 though it is possible that an artifi- 
 cial flux might be made of it. Steel 
 metal is in most cases white. It is 
 smelted by rather more ore than 
 that which will make grey iron ; 
 but not with so heavy a burden as 
 
 that which will make white iron 
 containing carbon in small amount. 
 Any ore which contains foreign 
 matter in such large amount as to 
 make the addition of lime as a flux 
 necessary, does not make good steel 
 metal. The only mode of working 
 the furnace is, of course, by means 
 of charcoal and the employment of 
 the cold blast. 
 
 The forge fires employed in con 
 verting the metal into steel do not 
 differ materiallyfrom those in which 
 iron is made. The hearth of the 
 former is generally larger and 
 deeper, and the blast is stronger 
 than that of the latter. Very little 
 iron is connected with it. The 
 bottom is generally formed of sand- 
 stone, and the sides of braise, or 
 charcoal-dust mixed with clay. The 
 practical manipulation at these 
 forge-fires varies according to loca- 
 lity, to the form of the furnace, and 
 the qualifications of the workmen. 
 The main principle involved may 
 be generalized under the following 
 proposition : If it is intended to 
 make steel instead of iron, the 
 metal should be melted before and 
 off from the tuyere ; and it should 
 be kept, when melted, always be- 
 low the blast, and never brought 
 above or into the blast. By due 
 attention to locality, everything 
 else may be easily regulated. A 
 skilful workman will soon ascertain 
 that a flat hearth, an iron lining, 
 and a strongly dipped tuyere will 
 not make steel, though it will make 
 iron, and that a weak blast will 
 tend to produce iron. 
 
 The crude steel, the result of the 
 first operation, is generally thrown 
 when red-hot into cold water, then 
 broken and sorted. The most sil- 
 very part, of the finest grain, is the 
 best. Fibrous or partially fibrous 
 bars are reserved for iron : they 
 make a superior quality of bar iron. 
 Bluish-looking steel is also thrown 
 aside, for it will become fibrous 
 iron before its impurities can be 
 removed. The crude steel, drawn 
 
STE 
 
 STEEL, BLISTERED. 
 
 STE 
 
 out into bars an inch or an inch 
 and a quarter square, is placed in 
 piles composed of six or eight pieces 
 then welded, and drawn out into 
 smaller bars. This process, called 
 refining, is repeated three or four 
 times, and each time the number 
 of bars in the pile is increased. 
 The smaller the bars of steel, and 
 the greater the number of them 
 placed together, the more perfect 
 will be the refined steel. The piles 
 are heated in a large blacksmith's 
 fire, by stone coal, which must be 
 sufficiently bituminous to form an 
 arch over the fire. Coal - slack, 
 mixed with loam, is frequently used 
 for this purpose ; but it increases 
 the waste of steel. The hammer 
 used for drawing steel should be 
 light, weighing no more than 150 
 pounds, and ought to make from 
 300 to 400 strokes per minute. 
 Great skill and dexterity are re- 
 quired to draw steel bars. It is 
 highly important to perform this 
 operation well, as the quality of the 
 steel is, in some measure, depend- 
 ent upon the manner in which it 
 has been hammered. 
 
 In those countries where German 
 steel is made, a remarkable article 
 is manufactured, which deserves 
 notice. It is harder than the best 
 cast iron, but so brittle that it can- 
 not bear any bending when cold. 
 This article is cast steel : it is de- 
 rived from the remelted steel me- 
 tal. From 200 to 250 Ibs. of this 
 metal are generally melted. "When 
 that quantity is melted; down in. 
 the bottom* of the forge^hearth, 
 a small portion of it is let off: it 
 should be tapped as low at the 
 bottom as possible. This mass, 
 which flows like cast iron or cast 
 steel, is broken into small pieces, 
 and pounded; into a flat piece of 
 wrought iron, which has a brim 
 drawn up around it : this piece 
 serves as a crucible. It is covered 
 with loam, and exposed to a heat 
 which will melt the cast iron, and 
 unite it firmly with the wrought 
 
 iron. The former then forms a thin 
 coating of steel over the one side 
 of the iron, of immense hardness. 
 This does not become soft, even 
 though a long time is consumed in 
 tempering it. Wrought-iron plates, 
 furnished with such a coating of 
 steel, are used as draw-plates for 
 wire. The holes for the wire are 
 punched when it is warm ; for, when 
 cold, its hardness is so extreme, 
 that no drill-bit can make any im- 
 pression. 
 
 Iron for Blistered Steel 
 
 England is not so celebrated for 
 the production of iron suitable for 
 the manufacture of steel as Sweden 
 and Russia, upon which countries 
 we must depend mostly for our 
 knowledge of the mode of working 
 it, and the kind of materials from 
 which iron for the steel factories is 
 made. 
 
 The peculiarities of such iron 
 are so remarkable, that, by means 
 of the most accurate chemical ana- 
 lysis, we cannot detect any differ- 
 ence between a given kind which 
 produces a superior, and another 
 kind which produces an inferior 
 steel. Were it possible to detect 
 this difference, it would prove to 
 exist in the cinders. The iron from 
 which blistered steel is made is a 
 soft, fibrous, often grained, wrought 
 iron, of a peculiar silvery whiteness. 
 It is made from mottled pig iron, 
 smelted from magnetic ore by char- 
 coal and cold blast. 
 
 In making pig iron for the ma- 
 nufacture of steel, the ore should 
 be carefully roasted by wood, char- 
 coal, or braise. The height of the 
 blast-furnace must not exceed 35 
 feet, and the result is still more; 
 favourable when it does not exceed i 
 30 feet. The boshes should mea- 
 sure about 9 or 9 feet. There 
 ought to be either no hearth at all,, 
 as iji the Swedish or Styrian fur- 
 naces, or one that is very low. 
 Blast of medium strength^ and tu- 
 yeres suu.'evvbat inclined into the 
 
STE 
 
 STEEL, BLISTERED. 
 
 STE 
 
 hearth, are requisite. Hot fjlast 
 must be rejected altogether. In 
 fact, the operation should be con- 
 ducted in such a manner as to pro- 
 duce mottled iron of great purity. 
 In fluxing the ore, lime can be em- 
 ployed, but only in such limited 
 quantity as not to cause the furnace 
 to smelt grey or white iron ; for 
 neither will be serviceable in the 
 manufacture of good steel. 
 
 In converting pig into bar iron, 
 the German forge is generally em- 
 ployed in Sweden, and for this pur- 
 pose may be considered the most 
 perfect. The refining process re- 
 sembles the boiling of iron : this is 
 required to make the texture of the 
 iron as uniform as possible. White 
 pig metal will not boil, and it works 
 too fast. Grey pig metal contains 
 a large amount of impurities, and 
 the greatest attention at the forge 
 will not remove them in sufficient 
 amount to answer any practical 
 purpose. 
 
 In making blistered steel, it is 
 essential to consider not only the 
 quality, that is, the chemical com- 
 position of the iron, but also its 
 form. The bars are generally flat : 
 good qualities are from an inch and 
 a quarter to two inches in width, 
 and half an inch thick. For ordi- 
 nary steel and for cast steel, the 
 thickness of the bars may be three- 
 quarters of an inch ; but in these 
 cases, more time is not only re- 
 quired in blistering, but the heart 
 of the bar is still imperfectly car- 
 bonized. Thin bars work faster, 
 and make a more uniform steel 
 than thick and heavy bars : the 
 latter are always more or less raw 
 inside, and contain too much car- 
 bon outside. If the iron is very 
 pure, it may be short, that is, with- 
 out fibres : it may be hard, if it is 
 at the same time strong. Impure 
 iron will not make steel of good 
 quality. As iron void of fibres is 
 generally more impure than that 
 containing fibres, the safest plan is 
 to convert all the iron into fibrous 
 
 452 
 
 iron. Coarse fibrous iron, what- 
 ever may be its strength, does not 
 make good steel : that with black 
 spots or streaks of cinder must be 
 avoided by all means. The indica- 
 tions of a good iron are, a silvery- 
 white colour, short fine fibres, a 
 bright metallic lustre, and an ag- 
 gregation so uniform, that black 
 spots cannot be detected with a 
 lens. The transformation of bar 
 iron into steel requires no special 
 skill or knowledge. The quality 
 of the steel is determined by the 
 quality of the iron from which it is 
 manufactured. 
 
 Blistered Steel. 
 
 The furnace for the conversion 
 of wrought iron into blistered steel 
 is from 12 to 15 feet wide, and 20 
 or 25 feet deep. A conical chim- 
 ney, 40 or 50 feet high, is designed 
 to lead the smoke above the roof 
 of the factory. The iron is placed 
 in boxes composed of fire-brick or 
 sandstone tiles: these boxes are 
 from 24 to 36 inches square, and 
 from 10 feet to 16 feet in length. 
 Square holes at one end of the 
 furnace serve for the admission of 
 the iron, and the entrance and exit 
 of the workmen. Holes are also 
 made in the ends of the boxes, 
 through which one or more of the 
 bars may be passed, for the pur- 
 pose of testing the degree of ce- 
 mentation, and the progress of the 
 work. The boxes are enclosed in 
 the furnace, which is provided with 
 a grate and fire-brick arch. The 
 iron, when placed in these boxes, 
 is imbedded and carefully laid edge- 
 wise in a cement composed of one 
 part hard charcoal, one-tenth part 
 of wood ashes, and one-twentieth 
 part of common salt. The mixture 
 is ground into a coarse powder un- 
 der edge-wheels. If the boxes are 
 10 feet in length, the iron bars may 
 be 9 feet J inches. The cement 
 is laid about 2 inches deep in the 
 bottom of the box. The bars of 
 
STE 
 
 STEEL, BLISTERED. 
 
 STE 
 
 iron are then put in edgewise, se- 
 parated by of an inch space, which 
 is filled with cement, and the top 
 of the bars covered to the depth of 
 ^ an inch. Upon this another layer 
 of bars is set, but in such a manner 
 that the second layer overlies the 
 space which separates the bars of 
 the first layer. In this way the box 
 is filled to within 6 inches of its 
 top. The remaining space is filled 
 with old cement powder, on the 
 top of which, finally, damp sand or 
 fire-tiles are placed. The fire ought 
 to proceed slowly, so that three or 
 four days shall elapse before the 
 furnace and the cement-boxes as- 
 sume a cherry-red heat. In fact, 
 the fire should be conducted in 
 such a manner that the heat may 
 be slightly increased every day 
 during the whole course of the 
 operation. A diminution of the 
 heat, from the time of starting, oc- 
 casions a loss both of fuel and 
 time, and is injurious to the chests. 
 A well-conducted heat will finish a 
 small box in four or five days, and 
 a couple of boxes, 3 feet square, in 
 ten or twelve days. The furnace 
 and boxes should be cooled very 
 slowly; for a sudden change of 
 temperature is very apt to break 
 the fire-tiles, or sandstone slabs, of 
 which the boxes are constructed. 
 The trial-bar, which passes through 
 the small hole in one of the ends 
 of the box, and in a corresponding 
 hole in the furnace wall, is some- 
 what longer than the other bars, 
 so as to be taken by a pair of tongs, 
 and pulled out of the box. There 
 are frequently several of such bars, 
 for a bar that is once pulled cannot 
 be returned; and if, in a case in 
 which there is but one trial-bar in 
 the chest, the bar is pulled too 
 soon, no further opportunity of 
 testing the progress of cementation 
 is afforded. The trial-bars are not 
 sufficiently long to project over the 
 wall of the chest. The trial-hole is 
 closed by a clay stopper. Six days 
 may be considered a sufficient time 
 
 for blistering bars of common steel, 
 such as spring steel, saw-blades, 
 and common files ; eight days for 
 shear steel and steel for common 
 cutlery; and ten or eleven days for 
 the better qualities of steel, and 
 common cast steel. Rods for the 
 finer sorts of blistered, and the 
 finest kinds of cast steel, are re- 
 turned to the boxes after the first 
 heat, and receive two or three blis- 
 tering heats, according to the qua- 
 lity of steel wished to be obtained. 
 From eight to twelve tons of iron 
 may be charged in two chests, and 
 from four to eight tons in case the 
 furnace contains but one chest. 
 Two small chests are preferable 
 to one large chest. The smaller the 
 chest, the -more uniform will the 
 steel become. The regulation of 
 the fire in the furnance is a some- 
 what delicate operation. Iron of dif- 
 ferent qualities requires a different 
 degree of heat ; but the heat can be 
 easily managed by recollecting that 
 it should be steadily increased every 
 day. If it is not sufficiently strong, 
 the iron will absorb but very little 
 carbon, and the work will proceed 
 slowly. If the heat is too great, 
 the rod iron will be converted into 
 cast iron, or, at least, into some- 
 thing similar to it ; for, after being 
 once overheated, it will not, even 
 with the greatest labour and atten- 
 tion, make good steel. If the heat 
 is carried so far as to melt the blis- 
 tered iron in the boxes, it is con- 
 verted into white plate-metal, the 
 kind from which German steel is 
 manufactured. But this melting 
 cannot well take place, and if it 
 should occur, the slow cooling of 
 the chests, which is equivalent to 
 tempering, will transform the white 
 metal into grey cast iron. The 
 latter is converted into steel with 
 greater difficulty than the white 
 metal. 
 
 Blistered steel, taken from the 
 chest, is very brittle: the excellence 
 of its quality is in proportion to its 
 brittleness. The presence of fibres 
 
STE 
 
 STEEL, BLISTERED. 
 
 STE 
 
 indicates that the cementation is 
 unfinished. A fine-grained, white 
 aggregation, like iron rendered cold- 
 short by phosphorus, indicates that 
 the cementation has not advanced 
 beyond its first stages. A crystal- 
 line form of the grains, is an in- 
 dication either of imperfect ce- 
 mentation, or of too low a heat, 
 or bad iron ; still, the best kind of 
 iron will exhibit these crystals, and 
 they can be observed by the lens, 
 if the temperature of the chests 
 has not been kept sufficiently high. 
 If a good article be desired, a repe- 
 tition of the operation is, in such 
 cases, necessary. The grains of 
 good steel appear like round glo- 
 bules, when taken from the chest 
 and broken. After an imperfect 
 cementation, the colour of the steel 
 iswhite. Good blisteredsteelshould 
 be of a greyish colour, and of a 
 bright lustre ; and it should exhibit 
 a coarse grain, as though it were 
 an aggregation of mica or leaves of 
 plumbago. That which exhibits a 
 fine grain, of crystalline form, and 
 which is of a white colour, is always 
 a poor article. But one degree of 
 heat is favourable for each kind of 
 iron : if that degree be hit upon, 
 the operation goes on well; if 
 otherwise, a favourable result can- 
 not be expected. The composition 
 .of the cement and the construction 
 of the boxes and furnace have little 
 influence on the quality of the steel. 
 Where the iron is of the best qua- 
 lity, and where the degree of heat 
 is most favourable, the fracture of 
 a bar taken from the chest will ex- 
 hibit the largest grains or leaves. 
 An indication of good iron is its 
 increase of weight in cementation ; 
 while bad iron neither gains nor 
 loses in weight, iron of good qua- 
 lity will gain at the rate of from 
 15 to 20 per cent. This applies 
 especially to strong and pure iron. 
 The surface of the rods, whatever 
 number of bliste rs they may have 
 when taken from the chest, must 
 be clean. Bad iron makes but few 
 
 blisters, or none at all : the surface 
 of the rods is rough. With the 
 quality of the iron the number and 
 size of the blisters increase. Da- 
 nemora iron draws blister close to 
 blister, and almost all of equal size. 
 Common iron, that is, charcoal 
 iron, raises but few blisters, and 
 these are of irregular size. The 
 best qualities of puddled iron raise 
 but few blisters. 
 
 As might be expected, the tex- 
 ture and quality of one bar, as well 
 as the average which a chest con- 
 tains, cannot be uniform. The in- 
 terior of a bar, like the interior of 
 the box, will be imperfect, while 
 the external parts will be overdone. 
 The steel should, therefore, be bro- 
 ken, sorted, and refined. Pieces 
 of uniform grain, as well as those 
 including the extremes of quality, 
 are piled, welded, and drawn out 
 into bars. This process must be 
 repeated, if the grain is not suffi- 
 ciently uniform for the desired pur- 
 pose. Upon the skill of the ham- 
 mer-man the quality of the steel, 
 in a considerable degree, depends. 
 Slow and heavy strokes and high 
 heats depreciate its value, while its j 
 quality is improved by a low heat 
 and fast work. Rolling steel in a 
 rolling-mill, or welding it in a re- 
 heating furnace, makes it brittle, 
 and transforms it into a kind of 
 cast iron. This result, however, 
 can be partially remedied by again 
 bringing the steel to the hammer. 
 The influence of the tilt-hammer 
 upon the iron is nowhere more ob- 
 servable than in the manufacture 
 of steel. It is impossible to make 
 good steel independently of proper 
 hammer machinery. The tempera- 
 ture at which the hammering should 
 be performed is a matter of consi- 
 derable importance : the steel will 
 be spoiled equally by a too high 
 as by a too low heat. The secret of 
 success appears to be the preven- 
 tion of crystallization, which takes 
 place at certain temperatures of the 
 metal. Under favourable condi- 
 
STE 
 
 STEEL, CAST. 
 
 STE 
 
 tions, definite compounds of car- 
 bon and iron are formed; and 
 these compounds crystallize: this 
 crystallization causes brittleness. 
 The greater the amount of foreign 
 matter which is combined with the 
 iron, the greater the brittleness. 
 Blows of the hammer quickly re- 
 peated, and the exposure of the 
 metal a short time to a low heat, 
 appear to be the means of prevent- 
 ing crystallization, at least, of di- 
 minishing its extent. A. sudden 
 change of temperature augments 
 the power of crystallization in the 
 highest degree. This makes the 
 iron hard, by giving rise to so 
 strong an affinity between the iron 
 and foreign matter, that the colour, 
 occasioned by the carbon disap- 
 pears. The carbon is enclosed in 
 the particles of iron, which is, in 
 turn, crystallized by means of its 
 strongly cohesive properties. White 
 plate-metal of great, purity, con- 
 taining carbon in large amount, is 
 harder than. the hardest cast steel, 
 b,ut the strength of its cohesive 
 1 properties, and the larger size of 
 its crystals, are the causes of its 
 brittleness. The best steel, if melt- 
 ed at a high heat, similar to that of 
 the blast-furnace, would appear in 
 the same form as plate-metal, and 
 would be quite as brittle. From 
 the facts here stated, a conclusion 
 may be drawn, that the impurities 
 which increase the cohesive power 
 of steel or iron may be retained, 
 and the formation of crystals still 
 be prevented. 
 
 Cast Steel. 
 
 The.irjegularity which is exhibi- 
 ted in the texture of common steel 
 gave rise to the invention of 
 cast steel. Common steel is bro- 
 ken into small pieces, and closely 
 packed into a, crucible made of 
 good fire-clay, That which is in 
 some degree more highly carbon- 
 ized than usual is best adapted 
 for cast steel ; because, in the 
 melting operation, it loses a por- 
 
 tion of its carbon. With the fire- 
 clay, plumbago or coke-dust is 
 mixed; but neither of these in- 
 creases its durability, though dimi- 
 nishing its liability to break on 
 account of sudden changes of heat. 
 This well-mixed mass is firmly 
 pounded in an iron mould, with a 
 movable, cone, for the interior. 
 The crucible .wjii.ch j& thus formed 
 is air-dried and slightly burned 
 before it is employed in the melt- 
 ing of cast steel. For this pur- 
 pose a crucible 5 inches wide at 
 the top, and 16 or 18 inches in 
 height, is generally employed. 
 Every precaution must be taken 
 tp prevent it from cracking; for, 
 in such a case, its contents are 
 generally lost. 
 
 The air-furnace for the fusion of 
 the steel is similar in construction 
 to those used by brass-founders : 
 it is 2 feet deep and 12 inches 
 square. The flue at the top i's 
 covered by a cast-iron trap-door. 
 The top of the furnace coTnfcides 
 with the plane of the floor df the 
 laboratory. Under the 'flbGr of 
 the latter is an arch, into Which 
 the grates of the furnace may be 
 emptied : this arch supplies the 
 furnace with air, and in it the 
 ashes accumulate. The cruci- 
 ble is placed on a support com- 
 posed of two thicknesses of fire- 
 brick, and its top is covered with 
 a lid. In many cases, pounded 
 glass and blast-furnace cinders are 
 laid on the top of : the steel, as 
 well to prevent the access of air 
 as the oxidation of the carbon ; 
 but, if the lid fits well, this pre- 
 caution is unnecessary: be'sides, 
 these materials generally tend to 
 glaze, and, as a consequence, to 
 crack the crucible. In large fac- 
 tories, ten or twenty furnaces may 
 be put in one row, each furnace 
 having its own chimney! ;; Iri' Eng- 
 land the fuel employed is' coke ; 
 but anthracite is far superior to 
 coke for this purpose. The more 
 compact the fuel, the better will 
 
STE 
 
 STENCH-TRAP. 
 
 STE 
 
 be the result. In feeding the fur- 
 nace with coal, great caution must 
 be observed ; for a sudden charge 
 of cold 'fuel is apt to crack the 
 crucible. For this reason, square 
 are preferable to round furnaces. 
 The heat of the furnace must be 
 conducted in such a manner that 
 the melting shall commence from 
 below, and not from the top. 
 This is another reason why the 
 form just described is preferable 
 to any other. All these advan- 
 tages are increased by the employ- 
 ment of blast, which, of course, is 
 essential where anthracite is used. 
 
 The time required to melt steel 
 depends partly upon the draught 
 of the furnace, partly upon the 
 quality of the crude steel, and 
 partly on the quality of the ar- 
 ticle designed to be manufactured. 
 From one to three hours is gene- 
 rally required for a crucible con- 
 taining 501bs. of metal. The 
 stronger the steel, the greater the 
 length of time consumed. The 
 mass must become perfectly li- 
 quid, no matter how long a time 
 is required to produce this result. 
 The liquid steel is then poured 
 into previously heated cast-iron 
 moulds, and cast in the shape of 
 square or octagonal bars, 2 inches 
 thick. Before casting, the steel 
 in the crucible is stirred with a 
 hot iron rod, after which a strong 
 heat is applied for a few minutes. 
 After casting, the top of the steel 
 in the mould is covered with clay, 
 to prevent its blistering, and to 
 prevent the access of air. 
 
 The cast rods are exposed to a 
 cherry-red heat, and put, when 
 almost black, to the hammer. The 
 rapid succession of strokes heats 
 the steel, and, if it is very hard, 
 often in too high a degree. Each 
 hammer requires a tilter and two 
 boys. In this case, as in that of 
 blistered or German steel, ham- 
 mering and heating need the ut- 
 most attention. The quality of 
 the steel depends upon the quick- 
 
 ness with which the work is per- 
 formed. The rods are heated in 
 heating stones, constructed like 
 sheet-iron ovens. 
 
 Steeler, the foremost or aftermost 
 plank in a strake, which is dropped 
 short of the stern or sternpost of a 
 vessel. 
 
 Steelyard, in statics, a kind of balance 
 having arms of unequal length, in 
 which the weight is moved along 
 the longer arm, and becomes in 
 effect heavier in proportion as it is 
 removed from the fulcrum or port. 
 It was formerly named the Statera 
 Romana, or Roman balance. 
 
 Steeple, a spire or lantern ; the su- 
 perstructure attached to the tower 
 of a church. 
 
 Steering-wheel, a wheel to which 
 the tiller-rope is attached, for the 
 convenience of steering a ship. 
 
 Sleeving, in navigation, denotes the 
 elevation which a ship's cathead 
 or bowsprit is above the stem, or 
 the angle which either makes with 
 the horizon. 
 
 Stem, the foremost piece of timber 
 in a ship. 
 
 Stem, in mining, a day's work. 
 
 Stemples, in mining, wooden pieces 
 by which to go up and down the 
 mine, instead of steps. 
 
 Stemson, a piece wrought on the aft- 
 part of the apron, continued as 
 high as the middle deck or upper 
 deck in small ships, the lower end 
 lapping on or scarfing into the 
 keelson. 
 
 Stench-trap, a contrivance for the 
 prevention of the escape of effluvia 
 from sinks and drains. These traps 
 are on the same principle as a 
 gasometer : a cup inverted in water 
 stops the escape of gas. (See the 
 following plan and section of a 
 trap in common use.) The cir- 
 cular plan shows how the fluid is 
 drained off through small holes. 
 The arrows in the section show 
 the course which the fluid takes 
 in its way into the pipe leading 
 into the drain. It will be evident, 
 from an inspection of the section, 
 
STE 
 
 STEREOSCOPE. 
 
 STE 
 
 that the inverted cup will be im- 
 mersed in the fluid as high as the 
 dotted lines. If, from neglect, the 
 space intended for fluid only should 
 
 Section of Stench-trap. 
 
 be suffered to become filled with 
 solid matter, the fluid will cease 
 to run in the direction indicated 
 by the arrows, and the utility of 
 the traps will be destroyed : they 
 should, therefore, be kept con- 
 stantly clear from solid matter. 
 
 Some persons, not understanding 
 the principle on which the trap is 
 constructed, remove the inverted 
 cup when the water can no longer 
 flow through it, and then leave it 
 off. The consequence is, that, there 
 being nothing to impede the gas 
 from the drains from rising and 
 flowing into the dwelling-houses, 
 the houses very frequently become 
 filled with noxious air. 
 
 Step, in ship-building, a large piece of 
 timber into which the heel of a 
 mast is fixed. 
 
 Steps for the masts are large pieces 
 fitted across the keelson, into which 
 
 the heel of <the mast is fixed. The 
 holes for the mast to step into 
 should be cut in proportion to the 
 steps, so as to leave sufficient wood 
 on each side of the hole to answer 
 in strength to the tenon left at the 
 heel of the mast ; and if that should 
 be rather too little the hole may 
 be cut more thwartships to answer 
 the deficiency the fore and aft way. 
 There are likewise large pieces 
 called steps of the cupstands ; and 
 steps on the top-side, for the con- 
 venience of getting on board. 
 Stereobote, or Stylobate, a base ; the 
 lower part or basement of a build- 
 ing or column. 
 Stereographic projection of the sphere; 
 
 projection. 
 Stereography, the art of representing 
 
 solids on a plane. 
 
 Stereometry, a science showing how 
 to measure, or to find the solid 
 contents. 
 
 Stereotomy, art of cutting solids, or 
 making sections thereof, as walls or 
 other members in profile of archi- 
 ture. 
 
 Stereoscope (The) has the property of 
 exaggerating the natural effects of 
 perspective and relief. An optical 
 delusion. 
 
 The mind judges of the relative 
 position, form, and magnitude of 
 visible objects, by comparing their 
 apparent outlines and varieties of 
 light and shade, with previously 
 acquired impressions of the sense 
 of touch. The knowledge that 
 such and such visual appearances 
 and optical effects are produced by 
 certain varieties of form, position, 
 and distance having been already 
 acquired, it substitutes with the 
 quickness of thought the cause for 
 the effect. The continual repeti- 
 tion of such acts, which are ne- 
 cessarily repeated as often as the 
 sense of vision is exercised, and 
 the extreme rapidity with which 
 all such mental operations are per- 
 formed, imagination of shape, dis- 
 tance and position are subjects of 
 visual perception. 
 
STE 
 
 STERN-POST. 
 
 STE 
 
 Exceptional cases^ however, are 
 of a class of visual phenomena 
 manifested independent of mere 
 outline and varieties of light and 
 shadow, and which no effort of art 
 can transfer to convas. Inasmuch, 
 also, as these phenomena are op- 
 tional effects of distance, form, and 
 position, they become, like the 
 others, indications hy which the 
 mind judges of the relative forms 
 and positions of the objects which 
 produce them. Phenomena of this 
 class are manifested, when the ob- 
 jects viewed are placed so near the 
 observer as to have sensible bino- I 
 cular parallax. The aspects under 
 which they are seen in this case by 
 the two eyes, right and left, are dif- 
 ferent. Certain parts are visible to 
 each eye which are invisible to 
 the other, and the relative positions 
 in which some parts are seen by 
 one eye, differ from those in which 
 the same parts are seen by the 
 other eye. This difference of as- 
 pect and apparent position, arises 
 altogether from the different posi- 
 tion of the two eyes in relation to 
 the objects. It is a phenomenon, 
 therefore, which can never be de- 
 veloped, in the case of objects 
 whose distance bears a large pro- 
 portion to the distance between the 
 eyes, because there is no sensible 
 difference between the aspects un- 
 der which such objects are viewed 
 by the one eye and the other. The 
 phenomenon, therefore, can only 
 be manifested in relation to objects, 
 whose distance from the observer 
 is a small multiple of the distance 
 between the eyes. 
 
 It appears that the two eyes, 
 right and left, will have different 
 views of the bust ; so that if the 
 observer were to make an exact 
 drawing of the bust with his left 
 eye closed, and another exact draw- 
 ing of it with his right eye closed, 
 these drawings would not be iden- 
 tical. One of them would show 
 a part of the bust on the extreme 
 right, which would not be exhibited 
 
 in the other, and the latter would 
 show a part on the extreme left, 
 which would not be included in 
 the former. Moreover, a part of 
 the cheek and the eye would be 
 shown in the drawing made with 
 the right eye closed, which would 
 not appear in the drawing made 
 with the left eye closed. 
 
 The stereoscopic pictures are ac- 
 cordingly produced upon daguer- 
 reotype plates, photographic paper, 
 or glass. On daguerreotype plates 
 they are necessarily opaque ; on 
 glass they are transparent ; and on 
 paper may be either opaque or 
 transparent, according to the thick- 
 ness and quality of the paper. 
 
 Since the greater number of ste- 
 reoscopic pictures represent views 
 of objects which must be so distat 
 from the observer as to have no 
 sensible binocular parallax, it may 
 be asked how it is that stereosco- 
 pic effects, so remarkable as those 
 which are manifested by such pic- 
 tures, can be produced. If the 
 stereoscopic effects be the conse- 
 quences of binocular parallax, and 
 of that alone, how can such effects 
 be produced by pictures of objects, 
 which have no such parallax ? 
 
 When the pictures are produced 
 on a small scale they are placed in 
 the stereoscope, the eye-glasses of 
 which will have the effect of caus- 
 ing them to be viewed in lines con- 
 verging at the same angle, as that 
 formed by the optic axes of the 
 two photographic instruments by 
 which the pictures were produced. 
 
 For a full and effective descrip- 
 tion of this subject see Dr. Lard- 
 ner's serial work. 
 Stern, the aft-part of a ship. 
 Sterne-frame, the frame of timber 
 that is composed of the stern-post, 
 transoms, and fashion-pieces. 
 Stern-post, the straight piece of tim- 
 ber at the aftermost part of a ship, 
 and to which both sides of the 
 ship unite : the lower end is te- 
 noned into the keel. It is gene- 
 rally worked with the butt-end up- 
 
STE 
 
 STONE. 
 
 STO 
 
 wards, being most suitable to the 
 conversion of the timber ; but in 
 some ships which trade to a hot 
 climate it has been preferred to 
 work the butt-end downwards, be- 
 cause in large ships it requires a 
 piece of such growth whose juices 
 towards the butt are nearly ex- 
 hausted, and therefore it is sup- 
 posed to last longer under water ; 
 whereas, by the heat of the wea- 
 ther, when the butt is worked up- 
 wards, it decays with dry-rot for 
 want of moisture. 
 
 Stern-sheets, in navigation, that part 
 of a boat which is contained be- 
 tween the stern and the hinder- 
 most seat of the rowers. 
 
 Stiff, in navigation, denotes the qua- 
 lity by which a ship is enabled 
 
 to carry a sufficient quantity of 
 sail without danger of overset- 
 ting. 
 
 Still-house. Rules are given for build- 
 ing these houses : the first caution 
 is to lay the floor aslope, not flat, 
 where any wet work is to be per- 
 formed. It should be also well 
 flagged with broad stones, so that 
 no wet be detained in the crevices, 
 but all may run off and be let out 
 at the drains made at the bottom 
 and sides. Stills for wines should 
 be placed abreast on that side of the 
 still-house to which the floor has 
 its current. Fronting the stills, and 
 adjoining to the back of the wall, 
 should be a stage for holding the 
 fermenting-backs ; so that these 
 being placed at a proper height, 
 may empty themselves by means of 
 a cock and a canal into the stills, 
 which are thus charged with very 
 little trouble. Near this set of 
 fermenting-backs should be placed 
 a pump or two, that they may 
 readily supply them with water by 
 means of a trunk or canal leading 
 to each back. Under the pave- 
 ment, adjoining to the stills, should 
 be a kind of cellar,whereon to lodge 
 the receivers, each of which should 
 be furnished with its pump to raise 
 the low wines into the still for 
 
 rectification ; and through this cel- 
 lar the refuse wash or still-bottoms 
 should be discharged, by means of 
 a hole or other contrivances. 
 
 Stilobatum, in architecture, denotes 
 the body of the pedestal of any 
 column. (See Stereobate.} 
 
 Stone is found in various forms and 
 conditions, embedded in and stra- 
 tified under the earth's surface. 
 That portion of it which is used 
 for building purposes, is a dense 
 coherent brittle substance, some- 
 times of a granulated, at others, of 
 a laminated structure ; these qua- 
 lities varying according to its che- 
 mical constitution and the mode in 
 which it has been deposited. Some- 
 times the laminated and granular 
 rocks alternate with each other; 
 at others, a rock of a mixed form 
 prevails, partaking of the charac- 
 teristics of both structures. Inde r 
 pendent of these properties is its 
 power of resistance to compression, 
 which depends chiefly upon its che- 
 mical combinations and the pres- 
 sure to which it has been subjected 
 whilst under the earth's surface 
 from the weight of superincumbent 
 materials. The granite also, and 
 other igneous rocks, owe their 
 hardness to their having crystal- 
 lized more or less rapidly from a 
 fused mass. 
 
 In attempting to ascertain the 
 ultimate powers of resistance of 
 rocks which have been deposited 
 by the action of water, it is neces- 
 sary to observe the direction in 
 which the pressure is applied, whe- 
 ther in the line of cleavage, or at 
 right angles to it. In nearly all of 
 the following experiments this pre- 
 caution was attended to, and it 
 will be seen that the strength is far 
 greater when the force is exerted 
 perpendicularly to the laminated 
 surface, than when it is applied in 
 the direction of the cleavage. In 
 building with such stone, it is also 
 important that it should be laid 
 in the same position as that in 
 which it is found in the quarry, as 
 
STO 
 
 STONE. 
 
 STO 
 
 the action of rain and frost rapidly 
 splits off the laminae of the stone 
 when it is placed otherwise. The 
 strength of the igneous or crystal- 
 line rocks is the same in every di- 
 rection, owing to the arrangement 
 of their particles. 
 
 It might have been advantageous 
 to have ascertained, by analysis, 
 
 the chemical composition of the 
 substances experimented on ; but 
 as this varies in almost every lo- 
 cality, and that in accordance with 
 the superincumbent and surround- 
 ing strata, this is of less conse- 
 quence in practice than a knowledge 
 of absolute facts in connection with 
 the properties of the material. 
 
 Experiments to determine the force necessary tojracture, and subsequently 
 to crush, 2-inch cubes of sandstone from the Shipley quarries, Brad- 
 ford. The pressure applied in the direction of the cleavage. 
 
 No. 
 
 of 
 Expt 
 
 Weights 
 laid on 
 in Ibs. 
 
 Remarks. 
 
 No. 
 of 
 Expt 
 
 Weights 
 laid on 
 in Ibs. 
 
 Remarks. 
 
 No. 1 Weights 
 of laid on 
 Expt in Ibs. 
 
 Remarks 
 
 Specimen No. 1. 
 Shipley. 
 
 Specimen No. 2. 
 Heaton. 
 
 Specimen No. 3. 
 Heaton Park. 
 
 12 
 13 
 
 31732 
 33524 
 
 fractured 
 
 11 
 12 
 
 31732 
 33524 
 
 fractured 
 crushed 
 
 8 
 9 
 10 
 jl 
 
 26356 
 28148 
 29940 
 31732 
 
 fracturec 
 crushed 
 
 16 
 
 38900 
 
 crushed 
 
 16 
 
 40692 
 
 Specimen No. 4. 
 
 Specimen No. 9. 
 Old Whatley. 
 
 Specimen No. 10. 
 Manningham-lane. 
 
 This specimen was de- 
 fective and crushed as the 
 first weight, 28148 Ibs., 
 was laid on. 
 
 11 
 12 
 13 
 
 31732 
 33524 
 35316 
 
 & crushed 
 
 fractured 
 suddenly. 
 
 8 
 9 
 
 14 
 
 26356 
 28148 
 
 37108 
 
 fractured 
 crushed 
 
 The results of the experiments 1, 2, 3, 9, 10, fractured and crushed in the 
 line of cleavage, are given in the following Table. 
 
 No. of 
 Specimen 
 
 1 
 2 
 3 
 9 
 10 
 
 Locality. 
 
 Size. 
 
 Weight at which 
 it fractured. 
 
 Weight at which 
 it crushed. 
 
 Shipley, Bradford. 
 Heaton . . . . 
 Heaton Park . . 
 Old Whatley . . 
 Manningham-lane. 
 
 2-in.cube. 
 
 33524 
 33524 
 29940 
 35316 
 28148 
 
 38900 
 40692 
 31732 
 35316 
 37108 
 
 
 Mean 
 
 
 32090 
 
 36749 
 
 
STO STONE. STO 
 
 Experiments to determine the force required to fracture, and subsequently 
 to crush, 2-inch cubes of sandstone from the Shipley and other quarries, 
 near Bradford. Pressure being applied at right angles to the cleavage. 
 
 No. 
 of 
 Sxpt 
 
 Weights 
 laid on 
 in Ibs. 
 
 Remarks. 
 
 No. 
 of 
 
 Expt 
 
 Weights 
 laid on 
 in Ibs. 
 
 Remarks. 
 
 Specimen No. 5. 
 Idle Quarry. 
 
 Specimen No. 6. 
 Jegrum's-lane. 
 
 15 
 16 
 17 
 
 18 
 
 38900 
 40692 
 42484 
 43380 
 
 fractured, 
 crushed. 
 
 18 
 19 
 
 22 
 
 44276 
 45172 
 
 47860 
 
 fractured, 
 crushed. 
 
 Specimen No. 7. 
 Spinkwell. 
 
 Specimen No. 8. 
 Coppy Quarry. 
 
 10 
 11 
 
 14 
 
 29940 
 31732 
 
 37108 
 
 fractured, 
 crushed. 
 
 14 
 
 16 
 18 
 
 37108 
 39796 
 41588 
 
 first fracture, 
 second fracture, 
 crushed. 
 
 Specimen No. 11 failed. 
 
 Results of experiments on specimens 5, 6, 7, 8, fractured and crushed at 
 right angles to the cleavage. 
 
 No. of 
 Specimen 
 
 Locality. 
 
 Size. 
 
 Weight at which 
 it fractured. 
 
 Weight with 
 which it crushed 
 
 5 
 
 Idle Quarry, Brad- 
 
 
 
 
 
 ford ' 
 
 2 -in. cube 
 
 42484 
 
 43380 
 
 6 
 
 Jegrum's-lane 
 
 
 45172 
 
 47860 
 
 7 
 
 Spinkwell 
 
 
 31732 
 
 37108 
 
 8 
 
 Coppy Quarry 
 
 " 
 
 37108 
 
 41588 
 
 
 Mean 
 
 
 39124 
 
 42484 
 
 By the foregoing experiment it required to fracture, and 100: 86 
 
 will be observed that the resisting 
 
 in the force required to crush this 
 
 powers of stone to compression, 
 
 description of stone. Hence, as 
 
 are greatest when the pressure is 
 
 already observed, the powers of re- 
 
 applied perpendicularly upon the 
 bed or laminated surface, and are 
 
 sistance of every description of la- 
 minated stone, are most effective 
 
 in the ratio of 100 : 82 in the force 
 
 when the beds are placed horizon- 
 
STO 
 
 STONE. 
 
 STO 
 
 tally or perpendicularly to the di- 
 rection of the pressure, and this 
 position is the more important 
 when the stone is exposed to the 
 atmosphere, as it partially prevents 
 
 the absorption of moisture, which 
 in winter tends to destroy the ma- 
 terial by the contraction of the 
 stone and the expansion of the 
 water at low temperatures. 
 
 Experiments to determine the force required to fracture and crush 1 in., 
 1^ in., and 2 in. cubes of stones, from Scotland, Wales, and other jjlaces. 
 
 No. 
 of 
 Expl 
 
 Weight 
 laid on 
 in Ibs. 
 
 Remarks. 
 
 No. 
 of 
 Expt 
 
 Weight 
 laid on 
 in Ibs. 
 
 Remarks. 
 
 Specimen No. 12. Grauwacke. 
 Penmaenmawr, Wales. 
 2-in. cube. 
 
 Specimen No. 14. Granite. 
 Mount Sorrel. 
 2-in. cube. 
 
 16 
 
 40692 
 
 slight fracture. 
 
 19 
 20 
 21 
 22 
 
 46068 
 47860 
 49652 
 51444 
 
 fractured, and after a 
 slight rest crushed. 
 
 29 
 30 
 31 
 
 63988 
 65780 
 67572 
 
 second fracture, 
 crushed. 
 
 Specimen No. 15. Grauwacke. 
 Ingleton. 
 2-in. cube. 
 
 Specimen No. 16. Granite. 
 Aberdeen. 
 2-in. cube. 
 
 13 
 
 20 
 25 
 
 35316 
 
 first fracture. 
 
 8 
 9 
 10 
 11 
 
 26356 
 27546 
 28148 
 28340 
 
 fractured, 
 not crushed. 
 
 47860 
 53236 
 
 second fracture. 
 
 not crushed. 
 
 Specimen No. 17. Syenite. 
 Mount Sorrel. 
 2-in. cube. 
 
 Specimen No. 18. Granite. 
 Bonaw. 
 l-in. cube. 
 
 17 
 
 18 
 19 
 20 
 
 42484 
 44276 
 46068 
 47284 
 
 crushed. 
 
 2 
 3 
 
 7 
 
 15604 
 17396 
 
 24564 
 
 f fractured into two 
 \ nearly equal parts. 
 
 crushed. 
 
 Specimen No. 19. Furnace Granite. 
 Inverary. 
 1^-in. cube. 
 
 Specimen No. 20. Granite. 
 1^-in. cube. 
 
 4 
 5 
 6 
 7' 
 
 19188 
 20980 
 22772 
 24564 
 
 crushed. 
 
 4 
 5 
 6 
 
 7 
 
 191.88 
 20980 
 22772 
 24564 
 
 fractured, 
 crushed. 
 
ITO STONE. STO 
 
 No. 
 of 
 3xpt 
 
 Weight 
 laid on 
 in Ibs. 
 
 Remarks. 
 
 No. 
 of 
 
 Expi 
 
 Weight 
 laid on 
 in Ibs. 
 
 Remarks. 
 
 Specimen No. 21. Limestone. 
 B. 
 H-in. cube. 
 
 Specimen No. 22. Limestone. 
 C. 
 H-in. cube. 
 
 1 
 
 2 
 3 
 4 
 
 13812 
 15604 
 17396 
 19188 
 
 fractured, 
 crushed. 
 
 2 
 3 
 4 
 5 
 
 15604 
 17396 
 18292 
 19188 
 
 fractured, 
 crushed. 
 
 specimen No. 23. Magnesian Lime- 
 stone. Anston. 
 1-in. cube. 
 
 Specimen No. 24. Magnesian Lime- 
 stone. Worksop. 
 1-in. cube. 
 
 1 
 
 2 
 
 10 
 
 1258 
 2154 
 
 3050 
 
 fractured. 
 
 13 
 14 
 
 3834 
 3946 
 
 fractured. 
 
 crushed. 
 
 38 
 
 7098 
 
 crushed. 
 
 Specimen No. 25. Sandstone. 
 1-in. cube. 
 
 Specimen No. 26. Sandstone. 
 2-in. cube. 
 
 8 
 9 
 
 13 
 
 2938 
 3050 
 
 3498 
 
 fractured. 
 
 11 
 12 
 
 20 
 
 9770 
 10218 
 
 12228 
 
 fractured. 
 
 crushed. 
 
 crushed. 
 
 Results of experiments on stone from North Wales and other places. Spe- 
 mens Nos. 12, 14, 17, 18, 19, 20, 21, 22, 23, 24, 25, and 26. 
 
 o. of 
 peci- 
 nen. 
 
 12 
 14 
 17 
 18 
 19 
 20 
 21 
 22 
 23 
 24 
 25 
 26 
 
 Description 
 of 
 Stone. 
 
 Locality. 
 
 Size. 
 
 Weight 
 with 
 which it 
 fractured, 
 in Ibs. 
 
 Weight 
 with 
 which it 
 crushed, 
 in Ibs. 
 
 67572 
 51444 
 47284 
 24564 
 24564 
 24564 
 19188 
 19188 
 3050 
 7098 
 3489 
 12228 
 
 Pressure 
 required 
 to crush a 
 2in. cube, 
 in Ibs. 
 
 Grauwacke 
 Granite ... 
 Syenite .... 
 Granite ... 
 
 
 
 Limestone 
 Sandstone 
 
 H 
 
 Penmaenmawr... 
 Mount Sorrel ... 
 
 Bonaw, Inverary 
 Furnace 
 (A) 
 (B) 
 (C) 
 A.nston 
 
 2 in. cube. 
 
 > 
 
 1 in. cube. 
 
 >3 
 5 
 
 1 in. cube. 
 }> 
 
 2 in. cube. 
 
 40692 
 51444 
 47284 
 17396 
 24564 
 22772 
 17396 
 18292 
 2154 
 3946 
 3050 
 10218 
 
 67572 
 51444 
 47284 
 43669 
 43669 
 43669 
 34112 
 34112 
 12200 
 28392 
 13992 
 12228 
 
 Worksop 
 
STO STONE. STO 
 
 The Welsh specimen of grau- 
 
 show experimentally the ratio of 
 
 wacke, from Penmaenmawr, ex- 
 
 the powers of resistance as the size 
 
 hibits great powers of resistance, 
 
 is changed. The results are suf- 
 
 nearly double that of some of the 
 
 ficiently near to prove that the 
 
 Yorkshire sandstones, and about 
 
 crushing weights are as the areas 
 
 one-third in excess of the gra- 
 
 of the surface subjected to pres- 
 
 nites, excepting only the granite 
 
 sure. 
 
 from Mount Sorrel, which is to 
 
 The specific gravity and poro- 
 
 the Welsh grauwacke as -7571 : 1. 
 
 sity of the different kinds of rock 
 
 Some others, such as the Ingleton 
 
 varv greatly : those from the neigh- 
 
 grauwacke, supported more than 
 
 bourhood of Bradford were carefully 
 
 the granites, but are deficient when 
 
 tested in regard to their powers 
 
 compared with that from Penmaen- 
 
 of absorption ; the experiments, 
 
 mawr. The specimen No. 23 is 
 
 which were conducted by Mr. 
 
 the stone of which the Houses of 
 
 Fairbairn with great precision, 
 
 Parliament are built. Specimens 
 
 gave the following results : 
 
 Nos. 25 and 26 were broken to 
 
 
 Experiments to ascertain the amount of water absorbed by various kinds 
 
 of stone. 
 
 a 
 
 
 
 
 Weight 
 
 
 
 " - 
 
 o g 
 d'S 
 
 Description 
 of 
 
 Locality. 
 
 Weight 
 jefore im- 
 
 after im- 
 mersion 
 
 )iffer'nce 
 of 
 
 Proportion 
 
 i ..i < 
 
 tel 
 
 Stone. 
 
 
 mersion. 
 
 for 
 
 Weight. 
 
 absorbed. 
 
 02 
 
 
 
 
 48 hour s. 
 
 
 
 
 
 
 Ibs. 
 
 
 
 
 I 
 
 Sandstone 
 
 Shiplev 
 
 5-4687 
 
 5-5546 
 
 0859 
 
 in 63-6 
 
 2 
 
 
 
 5-2578 
 
 5-3632 
 
 1054 
 
 in 49-S 
 
 3 
 
 
 Heaton Park 
 
 5-1718 
 
 5-2896 
 
 1171 
 
 in 44-1 
 
 4 
 
 
 
 5-2968 
 
 5-4726 
 
 1758 
 
 in 30-1 
 
 5 
 
 
 Idle Quarry 
 
 5'7178 
 
 5-8203 
 
 1016 
 
 in 5f-? 
 
 C 
 
 
 Jegrum's-lane .... 
 
 5-5976 
 
 5-7187 
 
 1211 
 
 in 40-2 
 
 7 
 
 
 Spinkwell 
 
 5-6757 
 
 5-7851 
 
 1094 
 
 in 53-8 
 
 8 
 
 
 Coppv Quarry .... 
 
 5-5703 
 
 5-6914 
 
 1211 
 
 in 46-C 
 
 9 
 
 
 OldWhatley 
 
 5-4720 
 
 5-6132 
 
 1406 
 
 in 38-f 
 
 10 
 
 
 
 Manningham-lane 
 
 5-4882 
 
 5-6093 
 
 1211 
 
 in 46-: 
 
 11 
 
 
 
 ? 
 
 5-6289 
 
 5-7539 
 
 1250 
 
 in 45-f 
 
 12 
 
 Grauwacke 
 
 Wales 
 
 6-4101 
 
 6-4140 
 
 0039 
 
 1 n 164H 
 
 13 
 
 Granite .. 
 
 Mount Sorrel .... 
 
 5-G875 
 
 5-6992 
 
 0117 
 
 in 485-( 
 
 14 
 
 M 
 
 > 
 
 5-8007 
 
 5-8124 
 
 0117 
 
 in 49.VI 
 
 15 
 
 Grauwacke 
 
 [ngleton . 
 
 5-7500 
 
 5-7539 
 
 0039 
 
 1 in 1962-1 
 
 
 
 
 
 
 
 
 From the above table it will be lated, take up much more watei 
 
 observed that specimen No. 15, 
 
 than the grauwackes, but less than 
 
 the Ingleton grauwacke, is the 
 
 the sandstones. The resistance o; 
 
 least absorbent, and No. 12, the 
 
 the grauwacke specimens to the 
 
 W r elsh grauwacke, absorbs almost 
 
 admission of water is four times 
 
 as little, while Nos. 9 and 14 of 
 
 that of the granite, and thirty-sis 
 
 the sandstones absorb most. The 
 
 times that of sandstone, such ae 
 
 granites, though closely granu- is found in the Yorkshire quarries 
 
 464 
 
TO STONE. STO 
 
 No. of Specimen. 
 
 Description 
 of 
 
 Stone. 
 
 Locality. 
 
 Size. 
 
 Speci- 
 fic 
 gra- 
 vity. 
 
 Pres- 
 sure 
 to 
 frac- 
 ture 
 speci- 
 men. 
 
 Pres- 
 sure 
 to" 
 crush 
 speci- 
 men. 
 
 Pres- 
 sure 
 per 
 square 
 inch 
 to crush 
 speci- 
 men. 
 
 Cubic 
 feet 
 in a 
 ton. 
 
 Eatios 
 of 
 powers 
 of 
 absorp- 
 tion. 
 
 1 
 2 
 3 
 
 4 
 5 
 
 6 
 
 7 
 8 
 9 
 LO 
 LI 
 o 
 L3 
 14 
 
 LO 
 
 16 
 .7 
 .8 
 L9 
 20 
 21 
 22 
 23 
 24 
 25 
 26 
 
 Sandstone 
 
 33 
 33 
 
 Grauwacke 
 
 Granite ... 
 
 Grauwacke 
 Granite . . . 
 Syenite ... 
 Granite . . . 
 
 33 
 
 Limestone 
 
 
 Sandstone 
 
 Shipley 
 
 cube 
 
 2 in. 
 
 33 
 
 t 
 
 3 
 
 
 
 
 55 
 33 
 
 U-m. 
 
 33 
 
 35 
 
 lin. 
 
 33 
 
 2m. 
 
 2-452 
 
 2-420 
 2-385 
 2-329 
 2-464 
 2-400 
 2-456 
 2-408 
 2-415 
 2-401 
 2-421 
 2-748 
 2-657 
 2-675 
 2-787 
 
 Ibs. 
 33524 
 33524 
 39940 
 defec- 
 42484 
 45172 
 31732 
 37108 
 35316 
 28148 
 fai 
 40692 
 
 51444 
 35316 
 27546 
 
 47284 
 17396 
 24564 
 22772 
 17396 
 18292 
 2154 
 3946 
 3050 
 10218 
 
 Ibs. 
 38900 
 40692 
 31732 
 tive 
 43380 
 47860 
 37108 
 41588 
 35316 
 37108 
 led. 
 67572 
 
 51444 
 
 (53236) 
 (28340) 
 
 47284 
 24564 
 24564 
 24564 
 19188 
 19188 
 3050 
 7098 
 3498 
 12228 
 
 Ibs. 
 9725 
 10173 
 7933 
 
 10845 
 11965 
 
 9277 
 10397 
 8829 
 9277 
 
 16893 
 
 12861 
 not crd 
 not crd 
 11821 
 10917 
 10917 
 10917 
 8528 
 8528 
 3050 
 7098 
 3498 
 3057 
 
 14-616 
 14-809 
 15-027 
 15-388 
 14-545 
 14-933 
 14-592 
 14-833 
 14-840 
 14-927 
 14-804 
 13-042 
 13-489 
 13-389 
 12-866 
 
 lin. 
 63-6 
 49-8 
 44-1 
 30-1 
 56-3 
 46-2 
 53-8 
 46-0 
 38-9 
 46-3 
 45-0 
 1641-0 
 485-3 
 495-0 
 1962-6 
 
 Jdeaton 
 Heaton Park ... 
 Spinkwell 
 
 Idle Quarry 
 Jegrum's-lane ... 
 Spinkwell 
 Coppv Quarry ... 
 OldWhatley ... 
 Manning'm-lane 
 
 Penmaeninawr 
 Mount Sorrel 
 
 Ingleton .: 
 Aberdeen 
 Mount Sorrel ... 
 Bonaw 
 
 Furnace 
 A 
 B 
 
 C 
 Anston 
 
 Worksop 
 
 D 
 
 E 
 
 On comparing the results of 
 the experiments on the Yorkshire 
 sandstones, it will be seen that 
 the difference of resistance to 
 pressure does not arise so much 
 from the variable character of the 
 stone in different quarries, as froi.i 
 the position in which it is placed 
 as regards its laminated surface, 
 the difference being as 10:8 in 
 favour of the stone being crushed 
 upon its bed to the same when 
 crushed in the line of cleavage ; 
 the same may be said of the lime- 
 stones. 
 
 Comparing the strengths indi- 
 cated by the above experiments, 
 there is found to be a very close 
 approximation in the granites, 
 but considerable difference in the 
 Yorkshire sandstones. Mr. Rennie 
 obtained his specimens from the 
 
 same district, the valley of the 
 Aire ; but the force required to 
 crush the Bromley Fall stone was 
 much less than that required to 
 fracture similar specimens from 
 the Shipley quarries. The follow- 
 ing table gives some useful re- 
 sults for comparison. 
 
 From the above it is evident 
 that there is a considerable differ- 
 ence between the results of Mr. 
 Rennie's experiments and those in 
 the preceding tables. This may, 
 perhaps, be due to the different 
 methods pursued in the experi- 
 ments, or from taking the first 
 appearance of fracture as the ulti- 
 mate power of resistance. Where- 
 as there is in some cases a differ- 
 ence of nearly a third between 
 the weight required to produce 
 the first crack, and that required 
 
 4G5 
 
STO 
 
 STONE. 
 
 STC 
 
 subsequently to crush tbJ speci- 
 men. This is the more remark- 
 able, as all the specimens did not 
 appear to follow the same law, 
 
 as in some the weight which frac 
 tured the specimen by a continua 
 tion of the process ultimate!} 
 crushed it. 
 
 Description of Material. 
 
 Crushing force 
 in Ibs. per 
 square inch. 
 
 Authority. 
 
 Porphvry 
 
 40416 
 
 Gauthey. 
 
 Granite, Aberdeen 
 
 11209 
 
 Rennie. 
 
 mean of 3 varieties . . 
 Sandstone, Yorkshire 
 
 11564 
 6127 
 
 Experiments 14, 18, 19. 
 Rennie 
 
 mean of 9 
 Brick, hard 
 
 9824 
 1888 
 
 Experiments 1 to 9. 
 Rennie. 
 
 red 
 
 805 
 
 Rennie. 
 
 
 
 
 The necessity of these experi- 
 ments was more apparent some 
 years since, in the construction of 
 the Britannia and Conway tubu- 
 lar bridges, when fears were enter- 
 tained of the security of the ma- 
 sonry to support, upon the given 
 area, the immense weight of the 
 tubes, upwards of 1,500 tons, 
 resting on one side of the tower. 
 To ascertain how far the material 
 (Anglesea limestone) was calcu- 
 lated to sustain this load, the fol- 
 lowing experiments were made : 
 
 BRICKWORK. 
 
 No. 1. 9-in. cube of cemented 
 brickwork (Nowell and Co.), No. 1 
 (or best quality) weighing 54 Ibs., 
 set between deal boards. Crushed 
 with 19 tons 18 cwt. 2 qrs. 22 Ibs. 
 zz 551*3 Ibs. per sq. inch. 
 
 No. 2. 9-in. cube of brickwork, 
 No. 1 weighing 53 Ibs., set in ce- 
 ment, crushed with 22 tons 3 cwt. 
 
 qr. 17 Ibs. = 6 12-7 Ibs. per sq. 
 inch. 
 
 No. 3. 9-in. cube of brickwork, 
 No. 3 weighing 52 Ibs. set in ce- 
 ment. Crushed with 16 tons 
 8 cwt. 2 qrs. 8 Ibs. = 454*3 Ibs. per 
 sq. inch. 
 
 No. 4. 9^-in. brickwork, No. 4 
 weighing 55^ Ibs., set in cement. 
 Crushed with 21 tons 14 cwt. 
 
 1 qr. 17 Ibs. zz568*5 Ibs. per square 
 inch. 
 
 No. 5. 9-in. brickwork, No. < 
 weighing 54^ Ibs., set betweei 
 boards. Crushed with 15 tons 
 2 cwt. qr. 12 Ibs. 417 Ibs. pe 
 sq. inch. 
 
 Mean of the above experiment 
 = 521 Ibs. per sq. inch. 
 
 The last three cubes of commoi 
 brick continued to support tin 
 weight, although cracked in all di 
 rections ; they fell to pieces whet 
 the load was removed. All tin 
 brickwork began to show irregula; 
 cracks a considerable time befon 
 it gave way. 
 
 The average weight supporte( 
 by these bricks was 33'5 tons pe; 
 square foot, equal to a column 
 583-69 feet high, of such brick, 
 work. 
 
 SANDSTONE. 
 
 No. 6. 3-in. cube red san 
 stone, weighing 1 Ib. 14f oz., set 
 between boards (made quite dn 
 by being kept in an inhabitet 
 room). Crushed with 8 tons 4 cwt 
 qr. 19 Ibs. = 2043 Ibs. per sq 
 inch. 
 
 No. 7. 3-in. cube sandstone 
 weighing 1 Ib. 14 oz., set in ce- 
 ment (moderately damp). Crushet 
 with 5 tons 3 cwt. 1 qr. lib. = 
 1285 Ibs. per sq. inch. 
 
 No. g. 3-in. sandstone, weigh- 
 ing lib. 15^-oz., set in cement 
 (made very wet). Crushed witl 
 
 466 
 
TO 
 
 STONE. 
 
 STO 
 
 with 4 tons 7 cwt. qr. 21 Ibs.zz 
 1085 Ibs. per sq. inch. 
 
 No. 9. 6-in. cube sandstone, 
 weighing 18 Ibs., set in cement. 
 Crushed with 63 tons 1 cwt. 2 qrs. 
 6 Ibs. =z 3924-8 Ibs. per sq. inch. 
 
 No. 10. 9-in. cubes and stone, 
 weighing 58^ Ibs., set in cement 
 (77^ tons were placed upon this 
 without effect, = 2042 Ibs. per sq. 
 inch, which was as much as the 
 machine would carry). 
 
 Mean of the above experiments 
 =z 2185 Ibs. per sq. inch. 
 
 All the sandstones gave way sud- 
 denly, and without any previous 
 cracking or warning. The 3-in. 
 cubes appeared of ordinary de- 
 scription ; the 6-in. was fine grained, 
 and appeared tough and of supe- 
 rior quality. After fracture the 
 upper part generally retained the 
 form of an inverted square pyra- 
 mid about 2 in. high and very 
 symmetrical, the sides bulging 
 away in pieces all round. The 
 average weight of this material 
 was 130 Ibs. 10 oz. per cube foot, 
 or 17 feet per ton. 
 
 The average weight required to 
 crush this sandstone is 134 tons 
 per square foot, equal to a column 
 2351 feet high of such sandstone. 
 
 LIMESTONE. 
 
 No. 11. 3'in. cube Anglesea 
 limestone, weighing 2 Ibs. 10 oz. 
 set between boards. Crushed with 
 26 tons 11 cwt. 3 qrs. 9 Ibs. zz 
 6618[lbs. per sq. inch. This stone 
 formed numerous cracks and splin- 
 ters all round, and was considered 
 crushed; but on removing the 
 weight about two-thirds of its area 
 were found uninjured. 
 
 No. 12. 3-in. limestone, weigh- 
 ing 2 Ibs. 9 oz., set between deal 
 boards. Crushed with 32 tons 
 6 cwt. qr. 1 Ib. = 8039 Ibs. per 
 sq. inch. This stone also began to 
 splinter externally with 25 tons 
 (or 6220 Ibs. per sq. in.), but ulti- 
 mately bore as above. 
 
 No. 13. 3-in. limestone, weigh- 
 
 467 
 
 ing 2 Ibs. 9 oz., set in deal boards. 
 Crushed with 30 tons 18 cwt. 
 3 qrs. 24 Ibs. = 7702-6 Ibs. per sq. 
 inch. 
 
 No. 14. Three separate 1-in. 
 cubes of limestone, weighing 2 Ibs. 
 9 oz., set in deal boards. Crushed 
 with 9 tons 7 cwt. 1 qr. 14 Ibs. = 
 6995-3 Ibs. per sq. in. All crushed 
 simultaneously. 
 
 Mean of the above experiments, 
 7579 Ibs. per sq. inch. 
 
 All the limestones formed per- 
 pendicular cracks and splinters a 
 long time before they crushed. 
 
 Weight of the material from 
 above ~ 165 Ibs. 9 oz. per cubic 
 foot, or 13| feet per ton. 
 
 The weight required to crush 
 this limestone is 471'15 tons per 
 square foot, equal to a column 
 6,433 feet high of such material. 
 
 Previously to the experiments 
 just recorded, it was deemed ad- 
 visable not to trust to the resisting 
 powers of the material of which 
 the towers of either bridge were 
 composed ; and, to make security 
 doubly sure, it was ultimately ar- 
 ranged to rest the tubes upon ho- 
 rizontal and transverse beams of 
 great strength, and by increasing 
 the area subject to compression, 
 the splitting or crushing of the 
 masonry might be prevented. This 
 was done with great care, and the 
 result is the present stability of 
 those important structures. 
 
 To the consideration of the prac- 
 tical builder the general summary of 
 results on the next page is submitted, 
 obtained from various materials, 
 showing their respective powers of 
 resistance to forces tending to crush 
 them. 
 
 Professor Hodgkinson has also 
 experimented on round and square 
 columns of sandstone from Ped 
 Delph, Littleborough, Lancashire, 
 a much harder stone than that 
 found on the banks of the Aire. 
 With regard to these experiments, 
 it appears " that there is a falling 
 off in strength in all columns from 
 
STO STONE. STC 
 
 General Summary of Results on Compression. 
 
 Description of Material. 
 
 Crushing 
 ! orce in Ibs. 
 per sq. inch. 
 
 Authority. 
 
 Iron 
 
 and ' 
 Steel. 
 
 Stone. ' 
 Timber. ' 
 
 Cast steel 
 Blister steel 
 Cast iron (white derived 
 from 14 meltings) . . 
 Ditto (from 12 meltings) . 
 Ditto (from ordinary cast- 
 
 2148161 
 163744) 
 
 89600J 
 40416 
 16893 
 11565 
 6127 
 9824 
 2185 
 8528 
 7579 
 5074 
 1888 
 805 
 1424 
 9771\ 
 9509 
 9363 
 8241 
 6402 / 
 5748 
 5674 
 5375J 
 
 Fairbairn's Experiments on 
 the Mechanical Properties 
 of Metals. Transactions 
 of the British Association 
 1854. 
 Gauthey. 
 Experiment No. 12. 
 Ditto Nos. 14, 18, 19. 
 Kennie. 
 Experiments 1 to 10. 
 Clark. 
 Experiments 21, 22, 
 Clark. 
 Experiments 23, 24. 
 Rennie. 
 
 Clark. 
 Hodgkinson, 
 
 
 Grauwacke, Penmaenmawr 
 Granite, mean of 3 . . . 
 Sandstone, Yorkshire . . 
 Ditto, mean of 9 exprmts . 
 Ditto, Runcorn .... 
 Limestone . 
 
 Ditto, Anglesea .... 
 Ditto, Magnesian mean . 
 
 Ditto red 
 
 v Ditto, mean of 4 exprmts. 
 /Box 
 
 English Oak (dried) . . 
 Ash (ditto) . . 
 Plum-tree (ditto) . . 
 Beech . . 
 
 Red Deal . . . 
 
 Cedar 
 
 s Yellow Pine 
 
 the shortest to the longest, but 
 that the diminution is so small, 
 when the height of the column is 
 not greater than about twelve times 
 the side of its square, that the 
 strength may be considered uni- 
 form, the mean being 10,000 Ibs. 
 per square inch or upwards. 
 " From the experiments on the 
 columns 1 in. square, it appears 
 that when the height is fifteen 
 times the side of the square, the 
 strength is slightly reduced ; when 
 the height is twenty-four times the 
 height of the base, the falling-off 
 is from 138 to 96 nearly ; when it 
 is thirty times the base, the strength 
 is reduced from 138 to 75 ; and 
 when it is forty times the base, the 
 strength is reduced to 52, or to 
 
 little more than one-third. Thesi 
 numbers will be modified to sonru 
 extent by experiments now in pro 
 gress. 
 "As long columns always giv< 
 way first at the ends, showing tha 
 part to be weakest, we might ec 
 nomize the material by makinj 
 the areas of the ends greater thar 
 that of the middle, increasing th< 
 strength from the middle both way 
 towards the ends. If the areas o 
 the ends be to the area of th< 
 middle, as the strength of a shor 
 column is to that of a long one 
 we should have for a column, whos< 
 height was twenty-four times th< 
 breadth, the areas of the ends ant 
 middle as 13,769 to 9595 nearly 
 This, however, would make th< 
 
 468 
 
STO 
 
 STONE-COAL FURNACES. 
 
 STO 
 
 ends somewhat too strong, since 
 the weakness of the long columns 
 arises from their flexure. 
 
 " Another mode of increasing the 
 strength would he that of prevent- 
 ing flexure, by increasing the di- 
 mensions of the middle. 
 
 " From the experiments it would 
 appear that the Grecian columns, 
 which seldom had their length more 
 than about ten times the diameter, 
 were nearly of the form capable of 
 bearing the greatest weight when 
 their shafts were uniform, and that 
 columns tapering from the bottom 
 to the top were only capable of 
 bearing weights due to the smallest 
 part of their section, though the 
 larger end might serve to prevent 
 lateral thrusts. This latter remark 
 applies, too, to the Egyptian co- 
 lumns, the strength of the column 
 being only that of the smallest part 
 of the section. 
 
 " From the two series of experi- 
 ments, it appeared that the strength 
 of a short column was nearly in 
 proportion to the area of the sec- 
 tion, though the strength of a larger 
 one is somewhat less than in that 
 proportion." 
 
 These extracts from Mr. Hodg- 
 kinson's paper show the advantages 
 to be derived from proper attention 
 to the construction of columns, not 
 only as regards their resistance to 
 a crushing force, but as to th'e pro- 
 priety of enlarging the ends to in- 
 crease their powers of resistance. 
 Experimental data cannot always 
 be applied in architectural construc- 
 tions ; but it is, nevertheless, essen- 
 tial that the architect and builder 
 should be cognizant of the facts, in 
 order that they may prepare their 
 plans, as far as possible, in accor- 
 dance with them, and effect the 
 greatest amount of work with the 
 least waste of material. 
 Stone - Coal Furnaces Anthracite 
 Furnaces (American). In eastern 
 Pennsylvania more than sixty blast- 
 furnaces, supplied by anthracite, 
 are most generally in operation. 
 
 469 
 
 These produce on an average from 
 seventy-five to eighty tons of iron 
 per week. This immense number 
 of furnaces, supplied by stone coal 
 alone, was the result of ten years' 
 industry; and the perfection to 
 which they have been brought is a 
 security that nothing can check 
 their use, or prevent their extension. 
 
 Anthracite furnaces resemble, to 
 a greater or less degree, coke and 
 charcoal furnaces. They are sel- 
 dom so high as coke furnaces, and 
 their horizontal dimensions are 
 usually greater than those of char- 
 coal furnaces. The following are 
 the dimensions of several of the 
 furnaces recently erected in eastern 
 Pennsylvania. One belonging to 
 Mr. Ecket, at Reading, is 37 feet in 
 height ; the top or throat 6 feet in 
 diameter; height of hearth, 5 feet ; 
 tuyeres, 22 inches above its bottom : 
 the hearth is 5 feet square at the 
 base, and 6 feet at the top; the 
 boshes are inclined 67^, or at the 
 rate of 6 inches to the foot, and 
 measure 14 feet at their largest 
 diameter. At the point where the 
 slope of the boshes joins the lining, 
 a perpendicular cylindrical space, 
 5 feet in height, commences, and 
 from this point the general taper to 
 the throat is continued in a straight 
 line. The hearth, as well as the 
 boshes, is built of coarse standstone. 
 but the latter are covered with a 
 lining of fire-brick, 9 inches thick. 
 The in-wall consists of two linings, 
 and the interior is the lining which 
 covers the boshes ; outside of this 
 is a space 4 inches wide, filled with 
 coarse sand, and this is protected 
 by a rough lining of slate, 2 feet 
 thick. The rough walls of the 
 stack are not heavy, but they are 
 well secured by binders. 
 
 Two furnaces erected at the 
 Crane Works, near Allentown, may 
 be considered as the greatest im- 
 provement. The stack is 35 feet- 
 high, 40 feet square at the base, and 
 at the top 33 feet. This furnace 
 is therefore but slightly tapered, 
 
STO 
 
 STONE-COAL FURNACES. 
 
 STO 
 
 and requires heavy stonework. It 
 generates steam from the trunnel- 
 head gas flame. At most anthra- 
 cite furnaces, this is done hy putting 
 the boilers on the top of the fur- 
 nace. The hearth is 5 feet high, 
 4 feet square at the bottom, and 
 6 feet at the top; the inclination 
 of the boshes is 75, and the cylin- 
 drical part of the in-wall above the 
 boshes is 8 feet high and 12 feet 
 in diameter. From the cylindrical 
 part up to the top, which is 6 feet 
 in width, the in-wall runs in a 
 straight line. 
 
 A furnace erected by Messrs. 
 Reeves and Co., at Phoenixville, 
 is 34 feet in height : the hearth is 
 6 feet high, 4 feet 3 inches square 
 at the bottom, and 5 feet 3 inches 
 at the top : the boshes taper 68, 
 or at the rate of rather less than 
 6 inches to the foot : they measure 
 13 feet at the widest part. Great 
 care is taken that the lining and 
 the boshes form a gradual curve, 
 that sticking and scaffolding in the 
 boshes may be obviated. The top 
 of this furnace is 8 feet square. 
 There is no doubt that the form 
 and construction of these anthracite 
 furnaces have been carried, within 
 the short space of a few years, to 
 so high a state of perfection as to 
 leave but little room for future im- 
 provements. Their shape is worthy 
 of imitation, particularly by Western 
 manufacturers; for coal adapted to 
 all of these furnaces is abundant in 
 the western States of America. 
 
 Most of these furnaces generate 
 the steam for the motive ppwer of 
 the blast as well as the heat for the 
 hot-blast apparatus at the top of the 
 furnace. In this way expense is not 
 only saved, but a uniform genera- 
 tion of steam and heating of air are 
 produced. The cost of erecting 
 such a furnace cannot be readily 
 estimated, as it must depend greatly 
 upon locality, material, wages, and 
 individual tastes ; but it may be 
 laid down as a general rule that a 
 stone-coal furnace costs less than 
 
 a coke furnace, and that, in most 
 cases, a good charcoal stack can be 
 altered so as to serve for stone 
 coal. 
 
 In the Western States, many 
 charcoal furnaces are in operation, 
 and there is no limit to their ex- 
 tension, so far as raw material, 
 wood and ore are concerned. One 
 circumstance, however, will neces- 
 sitate the introduction of stone-coal 
 furnaces in the West, namely, the 
 price of charcoal iron. Some lo- 
 calities can successfully compete 
 against stone-coal iron ; but those 
 which, besides enjoying that ad- 
 vantage, are situated near navi- 
 gable streams or canals, are very 
 few in number. It is said that 
 the average cost of producing char- 
 coal pig at Pittsburgh is 20 dollars; 
 some furnaces produce it at a cost 
 of 15 dollars: in as many cases, 
 however, 25 dollars is paid for iron. 
 The market price at Pittsburgh 
 varies from 25 to 30 dollars, ac- 
 cording to quality; and at this price 
 little profit is left to the owners of 
 the furnaces. How far the stone- 
 coal furnaces are in advance of this 
 will be shown by the following 
 statement of the average result of 
 three years' smelting. This state- 
 ment was furnished by Mr. Reeves, 
 of Philadelphia. 
 
 Amount of material consumed to pro- 
 duce one ton of iron at anthracite 
 furnace No. 1, at Phoenixville. 
 Tons. 
 
 Iron ore .... 2-59 
 Anthracite coal . . 1'83 
 
 Lime 1-14 
 
 Amount consumed at furnace No. 2, 
 at the someplace. 
 
 Tons. 
 
 Iron ore .... 2'65 
 Anthracite coal . . T89 
 Lime T15 
 
 These furnaces smelt brown he- 
 matite, hydrated oxide of iron. The 
 wages for producing one ton ol 
 anthracite iron, including all inci- 
 dental expenses, amount to 2 dollars 
 
STO 
 
 STONE OCHRE. 
 
 STO 
 
 50 cents, to which is to be added 
 the interest on capital employed. 
 
 Anthracite furnaces require wider 
 tops than coke furnaces, while the 
 latter require far wider tops than 
 charcoal furnaces. This width of 
 the top may be considered the most 
 essential improvement on the blast- 
 furnace which is supplied by an- 
 thracite coal. The height of the 
 stack in anthracite is much less 
 than in coke furnaces, and some- 
 what lower than in charcoal fur- 
 naces. Anthracite furnaces vary 
 from 30 to 35 feet in height; char- 
 coal furnaces, from 30 to 40 feet 
 in height ; and coke furnaces from 
 40 to 60 feet. The width of the 
 trunnel-head varies, in the United 
 States, considerably. In Pennsyl- 
 vania, Ohio, Kentucky, and Ten- 
 nessee, the width of furnaces at the 
 boshes is 9 and often 10 feet, and 
 at the top from 18 to 20 inches ; 
 or in the proportion of 30 square 
 feet at the boshes to 1 square foot 
 at the top. The Cold Spring fur- 
 nace measures at the boshes 9 feet, 
 and at the top 32 inches : here the 
 proportion is 11 feet at the boshes 
 to 1 foot at the top. 
 
 The dimensions of charcoal fur- 
 naces in Europe which smelt re- 
 fractory ores, are generally in the 
 proportion of 5 feet at the boshes 
 to 1 foot at the throat ; frequently 
 in the proportion of 4 to 1. In 
 coke furnaces, the proportion of 
 the horizontal section of the boshes 
 to that of the top is seldom less than 
 4 to 1. though sometimes even 2-5 
 to 1. In anthracite furnaces, the 
 diameter of the throat is 6 feet, and 
 that of the boshes 12 feet ; that is, 
 in the proportion of 1 to 4. But 
 sometimes the boshes measure 13 
 and the tops 8 feet square : in this 
 case, the proportion is as 2 to 1. 
 Taking into consideration the small 
 height of the stack, and the strong 
 blast which is applied, it is found 
 that this arrangement in anthracite 
 furnaces is, in an economical point 
 of view, very favourable ; for, in- 
 
 stead of retarding, it facilitates the 
 vent of the gases. Narrow tops 
 answer where loamy ore and soft 
 coal are used ; but, in such cases, 
 to obtain favourable results, weak 
 blast and high stacks should be 
 employed. But these conditions 
 can be observed only where coal 
 and labour are cheap. If any doubt 
 exists concerning the proper di- 
 mensions of a furnace, the best 
 course is to commence with a 
 comparatively low stack, wide 
 throat, and with as high a pressure 
 in the blast as the fuel will pos- 
 sibly bear. 
 
 Stone ochre. The true stone ochres 
 are found in balls or globular 
 masses of various sizes, in the solid 
 bodies of stones lying near the sur- 
 face of rocks among the quarries in 
 Gloucestershire or elsewhere. These 
 balls are of a smooth compact tex- 
 ture, in general, free from grit, and 
 of a powdery fracture ; they vary 
 exceedingly in colour, from yellow 
 to brown, murrey, and grey, but 
 do not differ in other respects from 
 the Oxfordshire ochre, and may be 
 safely used in oil or water in the 
 several modes of painting, and for 
 browns and dull reds in enamel. 
 
 Stools, pieces of plank fastened to a 
 ship's side to receive the bolting of 
 the gallery. 
 
 Stopper-bolts, large ring-bolts drove in 
 the deck of a ship before the main- 
 hatch, for the use of the stoppers. 
 
 Stopping, in mining, cutting down 
 mineral ground with a pick. 
 
 Stories, in architecture. Palladio di- 
 rects that the height of the story 
 immediately above the principal 
 floor be a sixth part less than that 
 below; and if there be an attic, 
 or third story, if should be nine- 
 twelfths of the height of that im- 
 mediately under it. 
 
 Stoup, an old English term for the 
 holy- water basin placed at the en- 
 trance to a church : it is applied 
 also to a vessel for carrying about 
 and distributingholy-water amongst 
 a Roman Catholic congregation. 
 
STR 
 
 STRENGTH OF MATERIALS. 
 
 STU 
 
 Stroke, in ship-building, one range of 
 planks fore and aft. 
 
 Strap, in carpentry, an iron plate 
 placed across the junction of two 
 or more tirrbers, either branched 
 out or straight, as may be found 
 requisite, and each branch bolted 
 or keyed with one or more bolts or 
 keys, through each of the timbers, 
 for the purpose of securing them 
 together. 
 
 Strata, in geology, extensive layers 
 of any mineral substance, such as 
 rocks, etc. Secondary strata are 
 nearly all comprised under the 
 heads of sandstone, limestone, and 
 shale. 
 
 Streamers, in mining, the persons 
 who work in search of stream-tin. 
 
 Stream-tin, in mineralogy, particles 
 or masses of tin found beneath the 
 surface of alluvial ground, and se- 
 parated from the earthy matter by 
 passing a stream of water over it : 
 hence the name. 
 
 Strength and stress of materials. The 
 works of Barlow and Tredgold con- 
 tain the most useful information 
 on these subjects. Barlow shows 
 that there are four distinct strains 
 to which every hard body may be 
 exposed, and which are, 1st, a 
 body may be pulled or torn asun- 
 der by a stretching force, applied 
 in the direction of its fibres, as in 
 the case of ropes, stretchers, king- 
 posts, tie-beams, etc. ; 2ndly, it 
 may be broken across by a trans- 
 verse strain, or by a force acting 
 either perpendicularly or obliquely 
 to its length, as in the case of 
 levers, joists, etc. ; 3rdly, it may 
 be crushed by a force acting in the 
 direction of its length, as in the 
 case of pillars, posts, and truss- 
 beams ; 4thly, it may be twisted 
 or wrenched by a force acting in a 
 circular direction, as in the case of 
 the axle of a wheel. 
 
 Stretching-course, in brickwork and 
 in masonry, a row or course in 
 which the bricks or stones are 
 placed with their longest faces ex- 
 posed to view. The bricks or stones 
 
 thus laid are called stretchers; and 
 those disposed with the ends out- 
 wards are called headers. 
 
 Strigce, in ancient architecture, what 
 are now called flutings. 
 
 String, in mining, a small vein. 
 
 String, the strake under the gunwale 
 withinside, generally worked the 
 same thickness as the sheer-strake, 
 and scarfed in the same manner: 
 the string and sheer-strake are 
 bolted through a ship's side. 
 
 String-course, a narrow, horizontal, 
 and slightly projecting course of 
 brickwork or masonry in the wall 
 of a building. 
 
 Stucco, in architecture, a composition 
 of white marble pulverized and 
 mixed with plaster or lime, but the 
 ingredients vary; it is employed 
 commonly for facing exterior and 
 interior works; it is also sometimes 
 used for floors 
 
 Stuck or Wulfs oven, a furnace for 
 the reduction of iron, at one time 
 common in Europe, now little em- 
 ployed. The interior of this fur- 
 nace has the form of two cones 
 ' united at their bases: it is usually 
 from 10 to 16 feet high, 24 inches 
 wide at bottom and top, and 5 feet 
 at the centre. There are generally 
 two tuyeres, both on the same side. 
 The opening called the breast is 
 closed after the furnace is heated, 
 after which, charcoal and ore are 
 thrown in, and the blast introduced. 
 As soon as the ore passes the tuyere, 
 iron is deposited at the bottom of 
 the hearth: when this amounts to a 
 ton, the blast is stopped, the breast 
 wall removed, and the metal lifted 
 out in a solid mass, or stuck, wulf, 
 as it is called by the Germans. 
 
 Studding-sails, in navigation, certain 
 light sails extended beyond the 
 skirts of the principal sails in mo- 
 derate steady breezes ; named also 
 ' goose-wings.' 
 
 Studies. In painting, these signify 
 works which a painter undertakes, 
 to acquire a practical knowledge 
 of his art and facility of execution. 
 The term is also applied to the 
 
STU 
 
 SULPHUR. 
 
 SUL 
 
 parts taken separately, which the 
 artist afterwards transfers to the 
 picture. 
 
 Stuffing -boxes, in a locomotive engine, 
 those with recesses for admitting 
 some soft material, such as white 
 spun-yarn, to render steam-tight 
 any rod working through this stuff- 
 ing or packing. The piston-rods, 
 slide-valve rods, regulator-rods, and 
 pump-plunger, all work through 
 stuffing-boxes of this description. 
 
 Stull, timber placed in the backs of 
 bevels and covered with boards, or 
 small piles, to support rubbish. 
 
 Sturt, in mining : when a tributer 
 takes a pitch at a high tribute, and 
 cuts a course of ore, he sometimes 
 gets two, three, or five hundred 
 pounds in two months : this great 
 profit is called ' a sturt.' 
 
 Styles of early Architecture in Eng- 
 land. The several examples, usually 
 denominated Gothic, are as follows: 
 1. The Anglo-Roman, which existed 
 about 300 years. 2. The Anglo- 
 Saxon, about 450 years. 3. The 
 Anglo-Norman (which continued in 
 use even on the introduction of the 
 Pointed style], about 85 years. 4. 
 Early Pointed (termed also the Lan- 
 cet style and early E-iglish], about 
 140 years. 5. The Pointed style 
 (called by some pure Gothic), about 
 110 years. 6. The Florid Pointed 
 (termed also the Perpendicular], 
 about 140 years. 7. The Tudor, 
 Elizabethan, and Stuart. 
 
 Stylobate, the substructure of a Greek 
 temple below the columns, some- 
 times formed of three steps, which 
 were continued round the peristyle; 
 and sometimes of walls raised to a 
 considerable height, in which case 
 it was approached by a flight of 
 steps at one end. 
 
 Subtangent, in geometry, in any curve 
 is the line which determines the 
 intersection of the tangent in the 
 axis prolonged. 
 
 Subtense, in geometry, the chord of 
 an arch; that which is extended 
 under anything. 
 
 Sucker, in mechanics, the embolus or 
 
 piston of a pump. In pneumatics, 
 a round piece of leather, which 
 laid wet on a stone and drawn up 
 in the middle, leaves a vacuum 
 within, which, by the pressure of 
 the atmosphere, makes it adhere. 
 
 Sulphate of copper (blue vitriol), in 
 chemistry, metallic salt, a com- 
 pound of sulphuric acid and copper. 
 
 Sulphate of iron (copperas or green 
 vitriol), in chemistry, a metallic 
 salt, a compound of sulphuric acid 
 and iron. 
 
 Sulphate of lead, an exceedingly white 
 precipitate from any solution of 
 lead by sulphuric acid, -much re- 
 sembling the blanc d'argent, and 
 which has, when well prepared, 
 quite neutral, and thoroughly edul- 
 corated or washed, most of the pro- 
 perties of the best white-leads, but 
 is rather inferior in body and per- 
 manence. 
 
 Sulphate of lime (gypsum, etc.), in 
 mineralogy, a compound of sul- 
 phuric acid and lime. 
 
 Sulphate of zinc (white vitriol), in 
 chemistry, a metallic salt, a com- 
 pound of sulphuric acid and zinc. 
 
 Sulphur, a simple combustible sub- 
 stance found native in a loose pow- 
 der, either detached or in veins. It 
 is met with in the neighbourhood 
 of volcanoes, where it is deposited 
 as a crust on stones contiguous to 
 them. It can be prepared by ex- 
 posing iron pyrites to heat, when 
 part of the sulphur is driven off in 
 vapour, and may be collected in 
 water: when vaporized, it condenses 
 in small crystalline particles, called 
 flowers of sulphur. It is inflam- 
 mable, burning slow with a pale 
 blue flame. Sulphur is found in 
 connection with silver, copper, lead, 
 antimony, and iron. Sulphur oc- 
 curs, in nature, crystallized in acute 
 octohedrons with rhombic bases. 
 It is principally brought to this 
 country from Sicily. 
 
 Sulphuret of hydrogen. This gas, com- 
 monly known as sulphuretted hy- 
 drogen, is invaluable as a re-agent 
 in separating one class of metals 
 
SUL 
 
 SURVEYING. 
 
 SUR 
 
 from another, is precipitated* by it 
 in acid solutions from another gas, 
 and only acted upon by it in alka- 
 line solutions. 
 
 Sulphurets of iron. Iron has a very 
 great affinity for sulphur: there 
 are five definite compounds of these 
 substances. It is very difficult to 
 separate iron from sulphur by heat 
 alone. Of the five different com- 
 positions, two only deserve atten- 
 tion, the white and yellow sul- 
 phurets. 
 
 White sulphuret of iron (while 
 pyrites} abounds in coal-beds, and 
 in the accompanying strata of clay ; 
 also in regular veins, along with 
 ores of lead, copper, and iron, in 
 the transition rocks. Before the 
 flame of the blow-pipe, it becomes 
 red ; upon charcoal, the sulphur is 
 evaporated, and oxide of iron re- 
 mains. It is very liable to decom- 
 position: it is preferable to the 
 yellow kind in the manufacture of 
 copperas, and is, in coal-mines, the 
 most dangerous of any, as it often 
 decomposes so quickly as to kindle 
 the coal-slack. Its composition is, 
 in 100 parts, 
 
 4.V07 iron. 
 
 53 35 sulphur. 
 9-58 manganese. 
 
 99-00 white pyrites. 
 Yelloio sulphuret of iron, yellow 
 pyrites. This variety becomes red 
 before the blow-pipe; and in the 
 reducing flame it melts into a glo- 
 bule, which continues red-hot for 
 a short time, and possesses, after 
 cooling, a crystalline appearance. 
 In nitric acid it is slowly soluble, 
 with the precipitation of sulphur, 
 but in no other acid. It is com- 
 posed of 
 
 47-30 iron. 
 
 52-70 sulphur. 
 
 100-00 yellow pyrites. 
 
 Yellow pyrites is almost identical 
 with the white pyrites, and the lat- 
 ter appears to be only different in 
 
 474 
 
 containing more foreign matter : 
 both are widely diffused among the 
 ores of iron, and are found in mas- 
 sive nodules, crystals, and veins, 
 in the coal-beds, clay-slate, grau- 
 wacke, greenstone, limestone, and 
 in beds of primitive slate. It is 
 the main material which is used for 
 manufacturing copperas, alum, oil 
 of vitriol, Spanish brown, and sul- 
 phur. 
 
 Summer, a horizontal beam or girder. 
 
 Sump, in mining, a pit sunk in the 
 engine-shaft below the lowest work- 
 ings. 
 
 Sump-shaft, the engine-shaft. 
 
 Supercilium, the transverse antepag- 
 ment of a doorway. The word is 
 also used to denote the small fillets 
 or bands above and below the scotia 
 of the Ionic base. 
 
 Superficies, in geometry, the surface 
 of any body or figure, considered 
 as possessing two dimensions, or 
 extension in length and breadth, 
 but destitute of thickness : in men- 
 suration, it is estimated as area. 
 
 Supporters, in heraldry, figures stand- 
 ing on a scroll and placed by the 
 escutcheon, such as the lion and 
 the unicorn in the British, and the 
 angels in the French arms. 
 
 Supporters, in ship-building, the 
 knee-pieces under the cathead. 
 
 Surmarks, in ship-building, the sta- 
 tions of the ribbons and harpings 
 which are marked on the timbers. 
 
 Surveying is the art of applying the 
 principles of geometry and trigo- 
 nometry to the measurement of 
 land. The principal operations are 
 laying down or driving base lines, 
 and triangles on either side of the 
 base. In large surveys it is de- 
 sirable to lay down these triangles 
 by measuring each angle with an 
 instrument called the theodolite, by 
 which the accuracy of the measure- 
 ment of the sides may be checked. 
 The theodolite is also avail- 
 able in fixing the true position of 
 points, the distances between which 
 are immeasurable, owing to the 
 intervention of buildings, rivers, or 
 
sus 
 
 SUSPENSION. 
 
 SUS 
 
 other obstacles. Rectangular or 
 irregular areas of land are similarly 
 reduced to triangles, and their exact 
 position referred to a base line. In 
 driving lines over land, three long 
 poles are requisite : these are ranged 
 in the direction of the intended 
 line at the greatest distance at 
 which they can be seen, either 
 with the naked eye or with the as- 
 sistance of a telescope, and driven 
 firmly into the ground. Interme- 
 diate stakes are then fixed, by 
 which the line is marked out. In 
 proceeding onward to extend the 
 line included between the front and 
 back pole, the latter only is re- 
 moved, and carried before the front 
 pole to the greatest practicable dis- 
 tance, and being ranged by the two 
 remaining poles, is there driven. 
 Thus the middle pole becomes the 
 back one, and is in like manner 
 removed to the front, and there 
 ranged and fixed : and in this 
 manner, by successively removing 
 the back pole, and conveying it to 
 the front, the line is extended as 
 far as necessary. These poles should 
 be as light as possible, consistent 
 with strength, and shod with iron 
 points, to facilitate driving. On 
 the top of each pole a flag or disk 
 is fixed, to render them conspicuous 
 from a long distance. Distances 
 are measured with a chain formed 
 of wire links, the length of the 
 chain being 66 feet, and formed 
 with 100 links, each link measuring 
 7*92 inches. The end of each chiin 
 is marked by driving a wire pin or 
 arrow into the ground, by counting 
 which the number of chains mea- 
 sured is ascertained. The base 
 line being thus driven and measured, 
 it is recorded in a book, and all 
 intersections offences, etc., marked, 
 and their relative distances on the 
 base are entered. A distant point 
 on either side of the base is then 
 determined, and a pole erected 
 upon it, and the distance of this 
 point from two fixed points upon 
 the base measured with the chain, 
 
 475 
 
 and duly recorded. By this means, 
 a triangle is completed, and after- 
 wards correctly filled in with all 
 intervening fences, etc. ; and by re- 
 peated processes of this kind the 
 survey is extended to any required 
 distance on each side of the base. 
 If the triangles first laid down are 
 of great extent, they should be de- 
 termined, and the position of their 
 angles ascertained with the theodo- 
 lite. This instrument consists of a 
 pair of horizontal circular plates, 
 the upper of which is called the 
 vernier plate, turning freely on a 
 centre upon the lower plate, the 
 edge of which is chamfered off, and 
 accurately graduated with degrees 
 and subdivisions. By these plates 
 and their adjusting screws, etc., 
 horizontal angles are measured, the 
 sight of the surveyor being aided 
 by a powerful telescope on the 
 upper part of the instrument, and 
 a microscope to read off the gradu- 
 ations upon the vernier. An upper 
 frame which carries the telescope 
 also supports a vertical arc or semi- 
 circle, which is likewise graduated, 
 and with the aid of another mi- 
 croscope the elevation of any high 
 object, as a tower, etc. (observed 
 through the telescope) may be cor- 
 rectly read off. This part of the 
 apparatus thus enables vertical an- 
 gles to be measured, and by the 
 application of trigonometry, heights 
 or distances may be thus exactly 
 determined without the actual mea- 
 surement of all the lines in each 
 vertical triangle. 
 
 Suspension, in mechanics, as in a 
 balance, are those points in the 
 axis or beam where the weights 
 are applied, or from which they 
 are suspended. 
 
 Suspension. Bridges of suspension 
 are of several kinds and of various 
 dimensions, consisting of several 
 iron chains, not formed of small 
 links, like cables, but of whole bars 
 of iron jointed at their ends, passed 
 over a tower, being the access to 
 the bridge on each side of the river, 
 
SWE 
 
 SYMPIESOMETER. 
 
 SYP 
 
 while their extreme ends are irmly 
 attached to large and ponderous 
 stones that are sunk a great depth 
 into the ground on each side of the 
 stream. These masses of masonry 
 are named abutments. The chains 
 hang in parallel festoons over the 
 river, between the supporting tow- 
 ers, and carry a number of vertical 
 bars of iron that are attached to and 
 hang down from them for the pur- 
 pose of suspending beams of wood 
 or iron hanging horizontally in the 
 direction of, or obliquely to, the 
 stream, and serving as joists to 
 support a strong planked platform 
 or roadway that extends across the 
 river: frequently these roadways 
 are paved, or at least gravelled or 
 ballasted over for horses, carriages, 
 and pedestrians. Extraordinary ex- 
 amples exist of this species of build- 
 ing in our own country, viz. that at 
 Bangor, crossing the Menai Strait, 
 by Telford, that at Hammersmith, 
 by Tierney Clark, Ilungerford, by 
 Brunei ; but the most extraordi- 
 nary structure is the stupendous 
 work of Tierney Clark, uniting 
 Pesth with Buda, in Hungary. 
 Mr. Dredge has constructed several 
 smaller bridges of suspension, ac- 
 cording to his arrangement, both 
 in England and Scotland. Suspen- 
 sion bridges have been constructed 
 also with wire as a material at 
 Fribourg, in Switzerland, and at 
 other places. 
 
 Sweep, or Tiller-Sweep, a circular 
 plank fitted to support the fore- 
 most end of the tiller, or handle of 
 a rudder, much improved by con- 
 veying the tiller-rope round it, and 
 keeping it always tight. 
 
 Swivel, in mechanics, something fixed 
 in another body so as to turn round 
 on it ; a kind of ring made to turn 
 round in a staple or other ring. 
 In artillery, a very small cannon, 
 which carries a shot of about half 
 a pound. 
 
 Sycamore, a species of Ficus, or fig- 
 tree, common in Egypt and other 
 parts of the East ; its timber is of 
 
 476 
 
 little value. The name is also ap- 
 plied to a species of maple, the 
 Acer Pseudo- Plat anus, a native of 
 the middle and south of Europe, 
 but common in England. The colour 
 of the young wood is silky white, and 
 of the old, brownish white ; the 
 wood of the middle age is in- 
 termediate in colour, and the 
 strongest. It is used in furniture, 
 pianofortes, and harps, and for 
 the superior kinds of Tunbridge 
 ware. Sycamore may be cut into 
 very good screws, and is used for 
 presses, dairy utensils, etc. 
 
 Symmetry, in sculpture, etc., adap- 
 tation of parts to each other ; pro- 
 portion ; harmony ; agreement of 
 one part with another. 
 
 Sympiesometer, a barometrical instru- 
 ment in which the atmospheric 
 pressure is indicated by the ascent 
 of a column of oil in a short glass 
 tube against the elastic pressure of 
 an enclosed volume of hydrogen 
 gas. Its indications require cor- 
 rection for the changes produced 
 by temperature on the gas. The 
 instrument is more compact, but 
 also more complex, than the mer- 
 curial barometer. 
 
 Synagogue, a word which primarily 
 signified an assembly, but, like the 
 word church, came at length to be 
 applied to places in which any as- 
 semblies, especially those for the 
 worship of God, met, or were con- 
 vened. Jewish synagogues were 
 not only used for the purposes of 
 divine worship, but also for courts 
 of judicature. The present ordi- 
 nary meaning of the term syna- 
 gogue is a Jewish church. 
 
 Syphering, in ship-building, lapping 
 one edge of a plank over the edge 
 of another for bulk-heads, making 
 the edges of the planks and the 
 sides of the bulk-head plain sur- 
 faces. 
 
 Syphon, a bent tube, having one leg 
 shorter than the other. It acts 
 from the pressure of the atmo- 
 sphere being removed from the 
 surface of a fluid, which enables it 
 
SYR 
 
 TALMUD. 
 
 TAL 
 
 to ris.e above its common level, 
 and is used for the purpose of 
 emptying liquors from casks, etc. 
 Syringe, a small hand-pump : in its 
 simplest form, it is provided with 
 a piston and rod, but is destitute 
 of valves, one simple aperture at 
 the extremity serving for the ad- 
 mission and ejection of fluid : those 
 
 constructed with valves, however, 
 are available, on a smaller scale, for 
 all the purposes of an air-pump. 
 Systyle, a term applied to a building 
 in which the pillars are closely 
 placed, but not quite so close as in 
 the pycnostyle, the intercolum- 
 niation being only two diameters, 
 or four modules, of the columns. 
 
 T. 
 
 TABERD (Saxon), a jerkin, a coat 
 without sleeves ; also, a herald's 
 coat. 
 
 Tabernacle, a movable fabric : among 
 the Jews, the name of a portable 
 temple which was constructed in 
 the Wilderness : the term is also 
 applied in Christian architecture 
 to richly ornamented niches. 
 
 Table, in architecture, a smooth, 
 simple member or ornament of 
 various forms, but most usually in 
 that of a long square. 
 
 Table or Tablet mouldings, horizontal 
 bands or mouldings, such as base- 
 mouldings, strings, cornices, etc. 
 
 Tables were in the Tudor age usu- 
 ally described as ' bordes,' and were 
 not in any great variety : the sorts 
 were but few, and little distin- 
 guished by workmanship ; but the 
 splendour of their coverings amply 
 compensated for the rudeness and 
 simplicity of the works so con- 
 cealed. The most elaborate em- 
 broidery, wrought on the finest 
 grounds, velvets and satins fringed 
 with gold and silver, Turkey car- 
 pets, and the choicest tapestry, 
 were used as table-covers. 
 
 Table-cloths, carpets, which at earlier 
 periods were almost the only co- 
 verings for dining-tables and cup- 
 boards; wiping was possessed by 
 the higher orders only. In 1520, 
 Thomas, Duke of Norfolk, be- 
 queathed his naperie to Agnes his 
 wife. 
 
 Tabling, in ship-building, letting one 
 piece of timber into another, in the 
 same manner as the beams are put 
 together. 
 
 Tablinum, an apartment of a Roman 
 house which was entered imme- 
 diately from the atrium, and in 
 which records were preserved in 
 cases, and the hereditary statues 
 placed. 
 
 Tack, in navigation, to change the 
 course or turn about a ship during 
 a contrary wind from the starboard 
 to the larboard, etc. 
 
 Tack, in navigation, a rope used to 
 confine the clues of the main and 
 fore courses forward, occasionally 
 in a fixed position : it has a large 
 wall-knot at one end. The word 
 has also various other applications. 
 
 Tacks, in navigation, the foremost 
 lower corner of all fore and aft 
 sails. 
 
 Tacking, in navigation, signifies a 
 manoeuvre by which a ship make* 
 an oblique progression to windward 
 in a zigzag direction, named also 
 ' beating to windward.' 
 
 Tackle, in mining, the windlass, rope, 
 and kibble. 
 
 Tcenia, the band or fillet surmounting 
 the Doric epistylium. 
 
 Taffrail, the carved work at the upper 
 part of the stern of a vessel, the 
 ends of w r hich correspond with the 
 quarter-pieces. 
 
 Tail-water, the waste water dis- 
 charged from the buckets of a 
 water-wheel in motion. 
 
 Talmud, or Thalmud, a book in great 
 veneration among the Jews, con- 
 tainingtheir doctrines and morality. 
 There are two of these works, the 
 old called the Talmud of Jerusalem, 
 the other, of Babylon ; the first, 
 composed by Rabbi Johanan, pre- 
 
TAL 
 
 TAPESTRY. 
 
 TAP 
 
 sident of the academy of Palestine, 
 about the 300th year of Christ: 
 this consists of two parts, the 
 Mishna, or the second law, con- 
 taining the traditions of the Jewish 
 doctors, collected about the year 
 190 by Rabbi Judah ; and the Ge- 
 mara, or the finishing or completing 
 the whole, which was done by 
 Johanan, and published both to- 
 gether. The Talmud of Babylon 
 contains also the Mishna, and the 
 Gemara of Rabbi Asa, of Baby- 
 lon, about the year 400: this is 
 much more valued than the other, 
 on account of its great clearness or 
 perspicuity, and also for its ex- 
 tensiveness, though it abounds in 
 fables and ridiculous stories, which 
 the Jews entertain with such eager- 
 ness, that they compare the Bible 
 to water, the Mishna to wine, and 
 the Gemara to hippocras, affirming 
 that Moses revealed those traditions 
 and explications to Aaron, to his 
 sons, and the elders, and that he 
 received them from God. 
 
 Talus, in architecture, the inclination 
 or slope of a work, as the outside 
 of a wall, where its thickness is 
 diminished by degrees as it rises 
 in height. 
 
 Tamping, \T\ mining, the material, usu- 
 ally soft stone, placed upon the gun- 
 powder to confine its force, which 
 would otherwise pass up the hole ; 
 also the process of placing the ma- 
 terial. 
 
 Tamping*iron, a tool used for beating 
 down the earthy substance in the 
 charge used for blasting. 
 
 Tangent, in geometry, a right line 
 perpendicularly raised on the ex- 
 tremity of a radius, which touches 
 a circle so that it would never cut 
 it, although infinitely produced, or, 
 in other words, it would never 
 come within its circumference. 
 
 Tank, that part of the tender of a loco- 
 motive engine which contains the 
 water : tanks vary in size, according 
 to the power of the engine to which 
 they are attached, and are from about 
 500 to 1600 gallons in capacity. 
 
 478 
 
 Tap, in mechanics, a hardened steel 
 screw with a square head, so that 
 it may be turned by a wrench : it 
 is grooved from end to end, and is 
 also slightly tapered : it is used 
 for cutting an internal screw, as 
 that of a nut, etc. 
 
 Tap-wrench, the handle for turning a 
 wrench. 
 
 Taper, a gradual diminution in the 
 size of a body, so as to form a 
 wedge or cone. 
 
 Taper-chain bridge, a suspension 
 bridge invented by Mr. Dredge. 
 
 Tapestry, or Arras, described as 
 ' hangings,' enriched the walls of 
 superior apartments from very early 
 times : the most ancient tapestry 
 now existing is preserved in the 
 church of Bayeux, in Normandy, 
 and exhibits an entire series of the 
 circumstances attending William 
 the Conqueror's descent in England. 
 The arras was loosely hung in pro- 
 jecting frames, by tenter-hoo s, 
 across the walls, which were some- 
 times not even plastered, covering 
 the whole surface from the floor to 
 the ceiling, and was, like most other 
 furniture, removable from one resi- 
 dence of its owner to another. The 
 most costly materials were em- 
 ployed in the fabrication of the 
 best sort of hangings. The apart- 
 ment of Henry VIII. at Calais, 
 whither he was accompanied from 
 Boulogne by Francis I. in 1520, was 
 hung with cloth of gold, adorned 
 with precious stones and pearls. In 
 the old inventories, cloth of gold, 
 and cloth of silver, and embroidery, 
 frequently occur, as well as cloth 
 of silk and gold mixed, called bal- 
 dikin. The walls of the gallery at 
 York House, the residence of Car- 
 dinal Wolsey, which was seized by 
 the king, were " hanged with cloth 
 of gold, and tissue of divers mak- 
 ings, and cloth of silver likewise 
 on both sides, and rich cloths of 
 bandikin ef divers colours." 
 
 Tappet-motion, the apparatus for 
 working the steam-valve of a Cor- 
 nish steam-engine, consisting of 
 
TAR 
 
 TEMPERATURE. 
 
 TEM 
 
 levers connected to the valves, 
 moved at proper intervals by tap- 
 pets or projecting pieces fixed on a 
 rod connected to the beam. 
 
 Tartan, a small coasting vessel of the 
 Mediterranean, with one mast, a 
 bowsprit, and a lateen sail. 
 
 Taunt, a sea term, signifying too high 
 or tall, as the mast of a ship. 
 
 Teak-wood is a native of the moun- 
 tainous parts of the Malabar coast, 
 of Java, Ceylon, etc. It grows 
 quickly, straight, and lofty. The 
 wood is light and porous, and easily 
 worked ; but it is nevertheless 
 strong and durable. It is soon 
 seasoned, and, being oily, does not 
 injure iron, and shrinks but little 
 in width. Its colour is light brown, 
 and it is esteemed a most valuable 
 timber in India for ship-building 
 and house-carpentry. It has many 
 localities. In twenty-five years the 
 teak attains the size of 2 feet dia- 
 meter, and is considered service- 
 able timber, but it requires 100 
 years to arrive at maturity. 
 
 Tegula, a roofing tile : roofing tiles 
 were made by the Greeks, like 
 bricks, of baked clay. 
 
 Telamqnes, or Atlaiites, statues of 
 men, employed in columns or pilas- 
 ters in classical architecture. 
 | Telegraph, a machine adapted for 
 communicating intelligence rapidly 
 at a considerable distance by means 
 of various signals previously ar- 
 ranged. 
 
 Telescope, a large optical instrument 
 for observing the celestial bodies, 
 whereby several new phenomena 
 have been discovered, and great 
 improvements made in astronomy : 
 by properly grinding and placing 
 the lenses" or glasses in a tube or 
 pipe of various lengths, objects at 
 a great distance are brought nearer 
 to the eye, and much more distinct- 
 ly seen than by the natural eye : 
 there are various kinds of tele- 
 scopes, which are called by distinct 
 names. 
 
 Temperature. The temperature of 
 the surrounding atmosphere exer- 
 
 479 
 
 cises a powerful influence in the 
 preservation or decomposition of 
 all organic bodies exposed to it. 
 Thus, while a high temperature 
 hastens the decay of animal and 
 vegetable matter, this is completely 
 arrested at or near the freezing- 
 point of water. Hence, by artificial 
 means, these substances may be 
 preserved for a length of time. A 
 citizen of the United States has 
 thus accomplished the means of 
 preserving meats, fruits, etc. A 
 large apartment is built under the 
 ground, the sides of which are 
 lined with a double wall containing 
 saw-dust : over the ceiling is a room 
 filled with ice, which, gradually 
 melting, filters through the saw- 
 dust, and keeps the temperature of 
 the underground apartment always 
 at 34 Fahr., or two degrees above 
 the freezing-point. In this apart- 
 ment, lemons, oranges, apples, 
 strawberries, flowers, etc., are pre- 
 served with complete freshness for 
 any length of time that may be re- 
 quired. 
 
 Temperature of different Thermome- 
 ters. A thermometer is an instru- 
 ment for measuring the tempera- 
 ture of bodies, or the degree of 
 intensity of their sensible heat. In 
 Europe there are three different 
 kinds of thermometers : 1. Fahren- 
 heit's, which is used chiefiyin Great 
 Britain, Holland, and North Ame- 
 rica, the freezing-point on which is 
 at 32?, and the boiling-point 212. 
 2. Reaumur's,which was that chief- 
 ly used in France before the Revo- 
 lution, and now generally used in 
 Spain and in some other Conti- 
 nental States : the freezing-point, 
 or zero, is 0, and the boiling-point 
 80 Q . 3. The Celsius, or Centigrade 
 thermometer, now almost univer- 
 sally used throughout France, and 
 in the northern and middle king, 
 doms of Europe : the zero or freez- 
 ing-point is 0, and boiling-point 
 100. Hence, in order to reduce 
 degrees of temperature of the cen- 
 tigrade thermometer, and of that of 
 
TEM 
 
 TEMPERATURE. 
 
 TEM 
 
 Reaumur, to degrees of Fahrenheit's 
 scale, and conversely, Rule I. 
 Multiply the centigrade degrees by 
 9, and divide the product by 5 ; or 
 multiply the degrees of Reaumur 
 by 9, and divide the product by 4 ; 
 then add 32 to the quotient in 
 either case, and the sum is the de- 
 grees of temperature on Fahren- 
 heit's scale. Rule II. From the 
 number of degrees on Fahrenheit's 
 scale subtract 32, multiply the re- 
 mainder by 5 for centigrade de- 
 grees, or by 5 for those of Reau- 
 mur's scale, and the product in 
 either case, being divided by 9, 
 will give the temperature re- 
 quired. 
 
 In all inquiries into the effects 
 of heat, it is necessary to attend to 
 the following rules respecting the 
 application of the term Temper- 
 ature : 
 
 Istly. If a body subject to no 
 pressure, or to a constant pressure, 
 have at two different times the 
 same bulk, it is said on both occa- 
 sions to have the same tempera- 
 ture. 
 
 2ndly. Two bodies are said to 
 have the same temperature, if, be- 
 ing kept in contact, the tempera- 
 ture of either remains unaltered by 
 the action of the other. 
 
 3rdly. When bodies of different 
 temperatures are in contact, the 
 temperature of the hotter body 
 decreases, and that of the colder 
 increases, till they become equal. 
 
 4thly. If the bodies be equal in 
 mass or in weight, and of the same 
 substance, the increase of tempe- 
 rature in one will be equal to its 
 decrease in the other. 
 
 Hence it will be seen that dif- 
 ferences of temperature are mea- 
 surable and comparable with each 
 other, quite independently of any 
 change of bulk ; that is, without 
 using the latter as a measure of 
 temperature, but only as a test by 
 which change of temperature is de- 
 tected. 
 
 In this way it has been disco- 
 
 covered that the same increment 
 (not equal increments, as from 40 
 to 50, and from 50 to 60) of 
 temperature causes all masses of 
 the same substance to expand in 
 the same ratio to their whole for- 
 mer bulk ; but this is by no means 
 the case with different substances, 
 as is obvious by looking at a com- 
 mon thermometer, an instrument 
 for measuring changes in the bulk 
 of a mass of liquid contained in a 
 glass vessel, of such a form that 
 changes, very small compared with 
 the whole bulk of the liquid, may 
 cause its surface to rise and fall 
 through a considerable space. 
 But this could not be done if the 
 glass and the measuring scale, in 
 undergoing the same changes of 
 temperature as the liquid, expe- 
 rienced also the same change of 
 bulk ; for, if such were the case, 
 the liquid surface would always re- 
 main opposite the same degree on 
 the scale. The value of this sim- 
 ple instrument therefore depends 
 on the fact that liquids are more 
 expansible than solids. 
 
 But it will further be seen that 
 the ratio of the change of bulk 
 to the whole bulk is different for 
 every different substance, when the 
 change of temperature is the same 
 in all. It is necessary, however, 
 to guard against a very common 
 error respecting the relation be- 
 tween temperatures and the num- 
 bers by which they are represented ; 
 namely, the degrees of the ther- 
 mometer. 
 
 Although the differences of tem- 
 peratures are known and compara- 
 ble quantities, yet their ratios are 
 not so : they can be compared by 
 addition and subtraction, but not 
 by multiplication or division. We 
 cannot say, " This temperature is 
 so many times that," because we 
 do not know the real zero of tem- 
 perature ; that is, we do not know 
 whatis the smallest bulk into which 
 a given body is capable of being 
 condensed by cold. We cannot, 
 
 480 
 

 
 M 
 
 TEMPERING. 
 
 TEM 
 
 therefore, say, " This body exceeds 
 its minimum bulk by twice as much 
 as that body exceeds its minimum 
 bulk ;" or, in other words, " This 
 body is twice as hot as that ;" for 
 although the temperature of one 
 body may be 80 and that of an- 
 other 40, these numbers are only 
 reckoned from an arbitrary zero or 
 starting-point, adopted because the 
 real zero is unknown. But al- 
 though we cannot say that A has 
 twice the temperatureof B, we can 
 say that the temperature of A ex- 
 ceeds that of B by twice as much 
 as the temperature of C exceeds 
 that of D. 
 
 The first question, then, regard- 
 ing the relation of expansion to 
 temperation, is " Do equal dif- 
 ferences of temperature cause the 
 bulk of a body to vary by equal 
 differences ?" This question had 
 to be settled before it could be 
 known whether the common ther- 
 mometer (the scale of which is 
 divided into equal parts) measured 
 differences of temperature cor- 
 rectly. For this purpose, Dr. 
 Brooke Taylor heated two equal 
 weights of water, one to 200 and 
 the other to 100, and on mingling 
 them together, he found them to 
 indicate exactly 150; thereby 
 showing that equal differences of 
 temperature cause equal differences 
 in the expansion of mercury; or 
 rather in the excess of its expansion 
 over that of glass, which is cleanly 
 all that the thermometer can mea- 
 sure. More accurate experiments, 
 however, have shown that this rule 
 does not exactly apply to any solid 
 or liquid, but only to gases. When 
 equal masses of the same liquid, at 
 different temperatures, are mixed, 
 their combined bulk becomes a 
 very little diminished. Liquids, 
 therefore, instead of expanding by 
 equal increments of space for equal 
 increments of temperature, expand 
 faster as the temperature increases 
 equably ; and it appears that the 
 correctness of the mercurial ther- 
 
 481 
 
 mometer observed by Dr. Brooke 
 Taylor was the result of a fortunate 
 coincidence, by which the expan- 
 sion of the glass, which is very 
 small compared with that of the 
 mercury, exactly compensated the 
 increasing rate of the latter. This 
 however, would not be the case 
 with thermometers constructed 
 with other liquids, for their rates 
 of expansion increase more rapidly 
 than that of mercury. Hence 
 spirit thermometers cannot be de- 
 pended on for temperatures above 
 the atmospheric range (or above 
 100). 
 
 Tempering, in metallurgy, the pre- 
 paring of steel or iron, so as to 
 render them more compact, hard, 
 and firm, or the reverse, more soft 
 and pliant. 
 
 Tempering of steel. Nearly every kind 
 of steel requires a particular degree 
 of heat to impart to it the greatest 
 hardness of which it is susceptible. 
 If heated, and suddenly cooled be- 
 low that degree, it becomes as soft 
 as iron: if heated beyond that de- 
 gree, it becomes very hard, though 
 brittle ; and its brittleness is an in- 
 dication of the degree of its heat, 
 when cooled off. These are the 
 reasons why, in hardening steel, it 
 is generally overheated, and then 
 tempered. To hit the exact heat 
 required is a matter of extreme 
 delicacy. 
 
 The hardening of steel may be 
 perfectly understood by studying 
 its nature. In endeavouring to 
 arrive at the temperature best 
 adapted to a particular case, a 
 case, for instance, in which a 
 strange kind of steel has to be dealt 
 with, a practical test, namely 
 drawing the bar into a tapered 
 point or chisel, is applied. This 
 wedge-shaped chisel will, of course 
 be more warm towards the point 
 than at the thick part; and it is 
 evident that this part will, when 
 cooled in the same cold medium, 
 be harder than the thick part. By 
 breaking, and continuing to break 
 
TEM 
 
 TEMPLE. 
 
 TEM 
 
 off, the point, the difference of 
 grain will show the different tem- 
 peratures which have been applied. 
 The finest and closest grained is 
 considered the best. In hardening 
 such steel, it is heated with a 
 due relation to the degree of the 
 test-heat. Though this manipu- 
 lation is very imperfect, careful and 
 intelligent workmen are generally 
 quite successful in arriving at a 
 knowledge of what degree is fa- 
 vourable. The degree of hardness 
 depends, in some measure, upon 
 the heat of the steel, but mainly 
 upon the difference between the 
 heat of the steel and that of the 
 water or medium in which it is 
 cooled. The coldest water will 
 make the hardest steel. Mercury 
 is better adapted to harden steel 
 than water; so is water acidu- 
 lated with any kind of acid, or con- 
 taining any kind of salt in solution. 
 The process of hardening is per- 
 formed with due relation to the 
 quality of the steel and the pur- 
 poses for which it is designed. In 
 most instances, the hardening is 
 effected in water or brine. Saw- 
 blades are thus hardened, after 
 being heated in melted lead ; and 
 sabres are heated in a choked fire 
 of charcoal, and then swung rapidly 
 through the air. Mint stamps are 
 hardened in oil or metallic compo- 
 sitions. The common method of 
 procedure in hardening is this : 
 The steel is overheated, cooled in 
 cold water, and then annealed or 
 tempered by being so far re-heated 
 that oil and tallow will burn on its 
 surface ; or the surface is ground 
 and polished, and the steel re- 
 heated until it assumes a certain 
 colour. The gradations of colour 
 consecutively follow : a light straw- 
 yellow, violet, blue, and finally grey 
 or black, when the steel again be- 
 comes as soft as though it had 
 never been hardened. 
 Templa, certain timbers introduced 
 in the roofs of temples ; they were 
 placed upon the canterii, or prin- 
 
 cipal rafters, extending the whole 
 length of the temple from one fas- 
 tigium to the other, corresponding 
 in situation and use with the com- 
 mon purlins. 
 
 Temple, a building set apart for the 
 services of religious worship, espe- 
 cially the Jewish, and those which 
 were dedicated to the heathen 
 deities : the name is not unfre- 
 quently applied to Christian sanc- 
 tuaries, for example, the Temple 
 church, London. The first Jewish 
 temple, built by Solomon, was 
 erected at vast expense ; the gold 
 and silver only, which was pro- 
 vided for the purpose, amounting, 
 it is said, to an almost incredible 
 sum. It was built much in the 
 same form as the Tabernacle, only 
 every way of larger dimensions. 
 It was surrounded, except the front 
 or east end, with three stories of 
 chambers, each 5 cubits square, 
 which reached to half the height 
 of the temple, and the front was 
 graced with a magnificent portico, 
 which rose to the height of 120 
 cubits, so that the shape of the 
 whole was notunlikesome churches 
 which have a lofty tower in the 
 front and a low aisle running along 
 each side of the building. This 
 temple was plundered by Nebu- 
 chadnezzar, King of Babylon, and 
 the building itself destroyed, ac- 
 cording to Josephus, after it had 
 stood between 400 and 500 years. 
 The second temple, erected after 
 the Jews' return from Babylon, 
 stood for 500 years, when Herod 
 rebuilt it in a style of great mag- 
 nificence. Tacitus, the Roman his- 
 torian, calls it a temple of immense 
 opulence. This magnificent temple 
 was at length destroyed by the 
 Romans in the same month and 
 on the same day of the month as 
 Solomon's temple was destroyed by 
 the Babylonians. Of the temples 
 of classic history, the most cele- 
 brated are those of Greece, con- 
 sisting of the Parthenon, built un- 
 der Pericles, the Erechtheum, and 
 
TEM 
 
 TEMPLE OF SOLOMON. 
 
 TEN 
 
 others noticed in Stuart's ' Anti- 
 quities,' and in the works of the 
 Dilettanti Society, of Cockerell, 
 Donaldson, etc. : of Rome, the 
 chief temples were, the Capitol, 
 the Pantheon (built by Agrippa), 
 the temple of Apollo, the temple 
 of Janus, and others interestingly 
 described by Degodetz, and also by 
 Taylor and Cresy. 
 
 Temple of Solomon had no arches. 
 In the Tabernacle, the Holy of 
 Holies, where the ark was placed, 
 was a cube of 15 feet. (Exod. 
 xxvi.) The Holy Place, where 
 the golden lamps and the table of 
 shew-bread stood, was a double 
 cube of 15 feet. In the Temple, 
 the Holy of Holies was a cube of 
 30 feet, the Holy Place a double 
 cube of 30 feet. 
 
 The whole structure was 90 feet 
 long and 45 feet high. The front 
 over the porch seems to have been 
 adorned with a towering edifice of 
 some kind or other, of an elevation 
 of 180 feet. 
 
 The Brazen Pillars, or two co- 
 lumns standing before the gate of 
 the Temple, seem to have been 6 
 feet in diameter and 52 feet 6 in. 
 high, or nearly 9 diameters (com- 
 pare 1 Kings vii. 15, with 2 Chron. 
 iii. 15, although there is in the 
 first passage a proportion of height 
 mentioned which causes some con- 
 fusion). The capitals were 6 feet 
 in diameter exclusive of their pro- 
 jecting ornaments, and 1\ feet high, 
 or one diameter and a quarter. 
 
 The portico of the Temple was 
 30 feet long and 15 feet wide, in 
 open height 45 feet. 
 
 The Cherubim on each side of 
 the ark were 15 feet high ; their 
 wings, which were extended to 
 meet each other, were 7 feet, and 
 the Cherubim and Palm-trees on 
 the wall, which were of carved work 
 covered with gold, seem to have 
 been of just the same proportion. 
 
 The greatest part of the cloisters 
 are affirmed to have been construc- 
 ted of beams of wood laid upon 
 
 483 
 
 massy pillars. Their outside wall 
 was of stone, 12 feet thick. 
 
 The roof was probably flat, ac- 
 cording to the general usage of 
 building in Eastern countries, as 
 we know that the Romans sta- 
 tioned a guard of soldiers on the 
 roof of the cloisters to preserve 
 order at public festivals. 
 
 Yet as the seditious Jews are 
 said to have set fire to the north- 
 west cloister in order to prevent 
 the Romans from taking the Temple 
 through the castle of Antonia; and 
 afterwards we are told that they 
 filled that part of the western 
 cloister which was between the 
 beams and the roof with dry ma- 
 terials and with bitumen and pitch, 
 and setting it on fire the flame burst 
 out on every side. There appears 
 a probability that the roof was not 
 flat, at least it is evident that the 
 interior ceiling was not the floor of 
 the external covering. 
 
 Templet, a gauge cut out of a thin 
 piece of metal to the form of the 
 work to be executed. 
 
 Templum (Latin), a temple. Tem- 
 ples appear to have existed in 
 Greece from the earliest times ; 
 they were separated from the pro- 
 fane land around them, and the en- 
 trances were much decorated as 
 architecture advanced. 
 
 Tenacity, that quality of bodies by 
 which they resist tension or tear- 
 ing asunder. 
 
 Tender, the carriage which is attached 
 to a locomotive engine, and con- 
 tains the supply of water and coke. 
 
 Tenon, in carpentry, the square end 
 of a piece of wood or metal dimin- 
 ished to one-third of its thickness' 
 to be received into a hole in ano- 
 ther piece, called the mortise, for 
 the jointing or fastening of the two 
 together. 
 
 Tension, a force pulling or stretching 
 a body, as a rod. Animals sustain 
 and move themselves by the ten- 
 sion of their muscles and nerves. 
 A chord, or string, gives an acuter 
 or deeper sound as it is in a greater 
 
TEN 
 
 TESSERA. 
 
 THE 
 
 or less degree of tension, th#t is, 
 more or.less stretched or tightened. 
 
 Tension-rod, an iron rod applied to 
 strengthen timber ormetal framing, 
 roofs, etc., by its tensile resistance. 
 
 Term, a piece of carved work placed 
 under each end of the taffrail of 
 a ship, at the side timbers of the 
 stern, and extended down as low 
 as the foot-rail of the balcony. 
 
 Terra Cotta, in the arts, baked earth, 
 bricks, tiles, etc. 
 
 Terra di Sienna, or Raw Sienna 
 Earth, a ferruginous native pig- 
 ment, which appears to be an 
 iron ore, and which may be con- 
 sidered as a crude natural yellow 
 lake, firm in substance, of a glossy 
 fracture, and very absorbent. It is 
 in many respects a valuable pig- 
 ment, of rather an impure yellow 
 colour, but has more body and 
 transparency than the ochres ; and 
 being little liable to change by the 
 action of either light, time, or im- 
 pure air, it may be safely used, ac- 
 cording to its powers, either in oil 
 or water, and in all the modes of 
 practice. By burning, it becomes 
 deeper orange and more trans- 
 parent and drying. 
 
 Terre-verte, an ochre of a bluish- 
 green colour ; in substance mode- 
 rately hard, and smooth in tex- 
 ture. It is variously a bluish or 
 grey coaly clay, combined with 
 yellow oxide of iron, or yellow 
 ochre. Although not a bright, it 
 is a very durable pigment, being 
 unaffected by strong light and im- 
 pure air, and combining with other 
 colours without injury. It has not 
 much body, is semi-transparent,and 
 dries well in oil. There are varieties 
 of this pigment ; but the green 
 earths which have copper for their 
 colouring matter are, though ge- 
 nerally of brighter colours, inferior 
 in their other qualities, and are not 
 true terre-vertes. 
 
 Tessellated, in the arts, variegated by 
 squares ; exemplified in the beau- 
 tiful pavements of the ancients. 
 Tessera, small cubical pieces of brick, 
 
 484 
 
 stone, or composition, forming part 
 of an ancient Roman mosaic or 
 tessellated pavement. 
 
 Testace ous, consisting of shells ; made 
 of baked earth, or of tiles or bricks. 
 
 Tetragon, a quadrangle, or a figure 
 having four angles. 
 
 Tetrahedron, in geometry, one of the 
 five regular bodies of 'solids com- 
 prehended under four equilateral 
 and equal triangles. It may be 
 conceived as a triangular pyramid 
 of four equal faces. 
 
 Tetrants, the four equal parts into 
 which the area of a circle is divi- 
 ded by two diameters drawn at 
 right angles to each other. 
 
 Tetrastyle, a portico, etc., consisting 
 of four columns. A cavsedium was 
 called tetrastyle when the beams 
 of the compluvium were supported 
 by columns placed over against the 
 four angles of a court. 
 
 Thatch, straw or reeds employed for 
 covering the roofs of buildings ; 
 particularly used for cottages. 
 
 Thaughts or Thwarts, in navigation, 
 the benches or seats in a boat. 
 
 Theatres, edifices of various but prin- 
 cipally of large dimensions, for 
 dramatic exhibitions. 
 
 Theatrum, a theatre. The Athenians, 
 before the time of vEschylus, had 
 only a wooden scaffolding on which 
 their dramas were performed. It 
 was merely erected for the time of 
 the Dionysiac festival, and was 
 afterwards pulled down. 
 
 Theodolite, in surveying, a mathe- 
 matical instrument for measuring 
 heights and distances. (See Hea- 
 ther's work on Instruments.) 
 
 Theorem, a term used in mathema- 
 tics to signify a proposition which 
 states a conclusion and requires its 
 demonstration ; as distinguished 
 from a Problem, which leaves the 
 conclusion to be discovered. 
 
 Theory, a doctrine which terminates 
 in the sole speculation or consi- 
 deration of its object, without any 
 view to the practice or application 
 of it. To be learned in an art, 
 the theory is sufficient ; to be mas- 
 
FHE 
 
 THEORY (MATHEMATICAL) EXPLAINED. 
 
 THE 
 
 ter of it, both the theory and prac- 
 tice are requisite. Machines often 
 promise very well in theory, but fail 
 in practice. A remarkable circum- 
 stance may be instanced of a gen- 
 tleman of British North America 
 selling his estate and leaving his 
 home to give practical effect to a 
 theory he had, as he considered, 
 beautifully worked out in figures, 
 for an important improvement in 
 steam-machinery. His theory, how- 
 ever, wholly failed on its first ap- 
 plication in practice. 
 Theory, mathematical, the algebraic 
 elucidation of the principles of any 
 physical system, where assumptions 
 are made, in the absence of positive 
 data: the calculated results are 
 expressed in formulae, which are 
 easily convertible into arithmetical 
 rules. Among others, the ' Theory 
 of the Steam Engine,' by the Count 
 de Pambour, has been found to 
 be most useful for practice; and 
 the following is an explanation of 
 his mathematical investigation, de- 
 signed for persons not familiar with 
 the algebraic signs, and intended 
 to render clear and easy the use of 
 the formulae contained in the above- 
 mentioned work, and which may be 
 said to have reference to all ma- 
 thematical works. 
 
 Among persons engaged in the 
 construction or working of steam- 
 engines, there is a great number to 
 whom the algebraic terms are little 
 familiar, and who usually give .ip 
 the readingof a hookas soon as they 
 perceive that it steps beyond the 
 simple notions of arithmetic. When 
 it is intended to make a work pro- 
 fitable to those persons, the usual 
 practice is to annex to each of the 
 definitive formulae an explanation, 
 in full words, of the arithmetical 
 operations which it represents. 
 
 The want of such explanation 
 may be very advantageously sup- 
 plied, by giving the signification of 
 everysign employed in the formulae; 
 by explaining what are the arith- 
 metical operations represented by 
 
 those signs. With the help of a 
 very few rules on this subject, per- 
 sons will find that the reading of 
 the formulae is quite as easy in 
 algebraic signs as if they were 
 written in words ; since, after all, 
 it is but an abridged way of ex- 
 pressing the same things, and, 
 moreover, the operations to be per- 
 formed, in order to attain the result, 
 are much more clear, and more 
 easy for the mind to seize. Again, 
 a perfect acquaintance with the 
 signification of the signs in common 
 use can require but a few hours of 
 attention, and when once a person 
 shall have made himself master of 
 them, he will be capable of reading 
 the formulae of all works. 
 
 A, B ..... a, b, ---- l,m,n,.. 
 .. a, ,.... etc. The letters are 
 an abridged manner of writing the 
 numbers which those letters repre- 
 sent. Thus, when the stroke of 
 the piston has been measured, and 
 found, for instance,to be 17^ inches, 
 it would be inconvenient to write 
 in all the formulae the number 1 7^. 
 But if the length of stroke, what- 
 ever it might be, has been repre- 
 sented by a letter, as /, for in- 
 stance, then, every time the letter 
 / occurs, there needs only to re- 
 collect that it represents the num- 
 ber 17 2-, and performing with that 
 number the operations indicated 
 in the formulae, relative to the 
 letter I, the result sought will be 
 attained. 
 
 = . . . . This sign signifies equal 
 to; it expresses that a quantity 
 sought is equal to the number re- 
 sulting from certain operations 
 performed on other quantities 
 known. Thus, for instance, if we 
 find the expression 
 
 this will signify that the quantity 
 V is equal to 60 times the quantity 
 v. Consequently, if we know be- 
 sides that the letter v represents 
 the number 100, it will follow 
 that the unknown quantity V will 
 
 485 
 
THE 
 
 THEORY (MATHEMATICAL) EXPLAINED. 
 
 THE 
 
 have for its value 60 times POO, or 
 6000. 
 
 + . . . . This sign signifies plus 
 (more). Placed between two let- 
 ters or two numbers, it indicates 
 that they are to be added together. 
 If, for instance, there be in a for- 
 mula an expression of the form 
 
 1 + 5, 
 
 it means that to the number 1 
 must be added the number 5. If, 
 then, we know besides that the 
 letter 8 represents the number '14, 
 it follows that the expression 1 + 5 
 will have for its value 
 
 1 + 5 = 1 + -14 = 1-14. 
 
 ... .This sign indicates minus 
 (less). Thus, when an expression 
 occurs of the form 
 
 P-/-2118, 
 
 the expression amounts to saying 
 that, from the number P the num- 
 bers/and 2118 are to be suc- 
 cessively subtracted. If, then, we 
 know that the letter P represents 
 the number 9360, and that the 
 lettery represents the number 144, 
 the expression will have for its 
 value 
 
 P -/- 2118 = 9360- 144 
 -2118 = 7098. 
 
 x .... This sign expresses mul- 
 tiplied by. Thus the expression 
 
 indicates that the two numbers 
 represented by the letters a and v 
 are to be multiplied one by the 
 other; and the product of that 
 multiplication will be the quantity 
 expressed here by a x v. This 
 multiplication to be performed is 
 equally expressed by a point be- 
 tween the two letters, or by writ-ng 
 the two letters simply together 
 without any sign interposed ; so 
 that the expressions 
 
 amount to the same, all three ex- 
 pressing the result of the mul- 
 
 tiplication of the numbers repre- 
 sented by a and v. If, for instance, 
 an expression occur like the fol- 
 lowing, 
 
 a r Vj 
 
 and it be known that the letter a 
 expresses the number 1-57, the 
 letter r the number 2640-96, and 
 the letter v the number 300, the 
 expression a r v will have the 
 value 
 
 1-57 x 2640-96 
 = 1243800. 
 
 300 
 
 -j- . . . . This sign denotes divided 
 by. Thus the expression 
 
 S 
 a 
 
 expresses S divided by a, or the 
 quotient resulting from the division 
 of the number expressed by S, by 
 the number expressed by a. 
 
 For instance, if we have S = '67 
 and a T57, it is plain that the 
 
 term _ will have for its value 
 a 
 
 -^=4268. 
 1-57 
 
 A fraction may have its nume- 
 rator or its denominator composed 
 of several numbers, on which di- 
 vers operations are indicated. In 
 that case, those operations must 
 first be performed, so as to reduce 
 the numerator and the denomina- 
 tor to single numbers, before per- 
 forming the division of the one by 
 the other, as has just been said. 
 
 If, for example, we have the 
 fraction 
 
 10000 
 1-492 + -002415 P' 
 
 and know besides that the letter P 
 represents the number 93GO ; we 
 must first perform the multiplica- 
 tion of the number 9360 by the 
 number -002415, and then add to 
 the product the number 1-492. 
 
 486 
 
'HE 
 
 THEORY (MATHEMATICAL) EXPLAINED. 
 
 THE 
 
 The result will be the number 
 24-0964, which will therefore re- 
 present the denominator of the 
 fraction. The fraction may then 
 be written under the form 
 
 10000 
 24-0964* 
 
 and consequently it is reduced to 
 the simple indication of the quotient 
 of two numbers, as in the preceding 
 case. 
 
 If two fractions occur, separated 
 by the sign of addition, or that of 
 subtraction, or that of multiplica- 
 tion, the meaning is that, after 
 having sought separately the quo- 
 tient indicated by each of those 
 fractions, they are either to be 
 added together, or one deducted 
 from the other, or one multiplied 
 by the other. Thus, the expression 
 
 10000 
 
 1-492 + -002415 P 
 
 signifies that, after having sought 
 the quotient indicated by each of 
 the two fractions, the first of these 
 quotients is to be multiplied by 
 the second. Supposing the letters 
 to be of the same numerical value 
 as in the preceding cases, the pro- 
 duct of the two fractions would 
 here be the definitive number 176. 
 It would be the same if we 
 were to find one fraction divided 
 by another. Each of them should 
 be first reduced to a single numler 
 by finding the quotient they repre- 
 sent, and then the one of these 
 quotients divided by the other. 
 
 ( ) or [ ] or { } . . . . Paren- 
 
 theses indicate that the different 
 quantities contained between them 
 are to be reduced to a single num- 
 ber before performing the other 
 operations indicated in the formula. 
 Thus, for instance, if we find in 
 a formula the expression 
 
 (1 + 5) v, 
 this means, that it is the expression 
 
 (1 + 5) entire, which is to be 
 multiplied by v. The sum then of 
 1 + 5 is first to be formed, and 
 afterwards multiplied by the num- 
 ber v ; whereas, had we only 
 
 1 + 80, 
 
 this would mean that the product 
 S v is first to be formed, and after- 
 wards the number 1 added to it. 
 
 There may occur several paren- 
 theses comprised one within the 
 other, but their signification is 
 always the same. The expression 
 
 002415 [(1 + 5)r +/] 
 
 denotes that the sum of 1 + 5 is 
 to be formed first, this to be mul- 
 tiplied by r, and the product added 
 to the quantity/, which gives the 
 number represented by the outer 
 parenthesis ; and finally, that this 
 number is to be multiplied by 
 002415. 
 
 Lastly, when there occurs in 
 the formulae a letter with a small 
 figure or exponent above it, it is 
 the same thing as writing that 
 letter as many times successively as 
 there are units in the figure or ex- 
 ponent. 
 
 For instance, the expression 
 
 is equivalent to the expression 
 v x v, or v written twice; that is 
 to say, it is the product of v by 
 itself. If then v were known to be 
 equal to 300, the quantity repre- 
 sented by v 2 would be 
 
 v 2 = 300 x 300 = 90000. 
 
 These short explanations are all 
 that is necessary, in order to read 
 and perfectly understand all prac- 
 tical formulae. Replacing each of 
 the signs that are met with in a 
 formula, by the periphrasis which 
 the sign represents, you read the 
 formula such as it ought to be ex- 
 pressed ; and effecting the arithme- 
 tical operations indicated by those 
 signs, you attain the result sought. 
 A formula is, then, nothing more 
 
 487 
 
THE 
 
 THEORY (MATHEMATICAL) EXPLAINED. 
 
 THE 
 
 than an abridged manner of Writing 
 the series of operations to be per- 
 formed, in order to arrive at the 
 result which we want to obtain. 
 
 We will subjoin to this explana- 
 tion some examples, taken from 
 the practical formulae of high- 
 pressure engines. 
 
 I. Suppose we have the formula 
 
 _ 8 10000 
 
 ~~ a ' 6-6075 + '00:2415 [(!'+) r+/]' 
 
 which is intended to determine 
 the unknown value oft?; and let 
 it be supposed that we know, be- 
 sides, that the other letters com- 
 prised in this formula have the 
 following value : 
 
 S- = -67 
 
 a = 1-57 
 
 5 = -14 
 
 r = 2641 
 
 f = 144. 
 
 First form the sum (1+5), indi- 
 cated in the inner parenthesis, 
 which will be 
 
 1 + 5 = 1-14. 
 
 Then multiply this number by r, or 
 2641, and the result will be 
 
 (1 + 5) r= 1-14x2641 =3010. 
 
 Add to this/, or 144, and the sum 
 will consequently be the quantity 
 indicated by the outer parenthesis, 
 
 [(l+5)r+/]=3154. 
 
 Now multiply this sum by the num- 
 ber -002415, and the product will 
 evidently be 
 
 002415 [(1+5) r + f] =-002415 x 
 3154 = 7-6170. 
 
 Add to this last result the number 
 6'6075, and you obtain 
 
 6-6075+ -002415 [(l+5)r+/] = 
 6-6075 + 7-6170 = 142245. 
 
 This is then the denominator of 
 the fraction which forms the second 
 member of the formula. Perform- 
 ing the division of the number 
 
 10000 by the number just obtained, 
 the quotient will be 
 
 10000 
 
 6-6075 + -002415 [(l+5)r +/J 
 10000 
 
 14-2245 
 
 703-04 
 
 On the other hand, dividing S 
 by a, or the number -67 by the 
 number 1-57, you have the value 
 
 a 
 
 of the fraction -, viz. 
 a 
 
 -=r^=' 4268 
 
 a 1-57 
 
 Finally, then, multiplying this lat- 
 ter quotient by that obtained im- 
 mediately above, you have defini- 
 tively 
 
 _ S 10000 
 
 = a' 6-6075 + -002415[(1 + 5)r +/] 
 = 4268x703-04=300. 
 
 Thus it is clear that by effecting 
 successively the series of calcula- 
 tions indicated by the few signs 
 which are explained, and proceed- 
 ing gradually from the most simple 
 terms to the more compounded 
 ones, we arrive without difficulty 
 at the definitive result. 
 
 We will give some other exam- 
 ples of these calculations ; but, in- 
 stead of effecting the operations, 
 we will merely express in words 
 the signification of the formula, 
 which amounts to the same. 
 
 II. Suppose we have the formula 
 
 1 + 5 
 
 (2736 +/); 
 
 this signifies that the required value 
 of a r will be obtained by perform- 
 ing the following arithmetical ope- 
 rations : 
 
 Add 1 to the number represented 
 by the letter 5, and multiply the 
 sum by the number v. 
 
 Then divide the number S by 
 the product thus obtained ; multi- 
 ply the quotient of this division by 
 the number 4140750; and write 
 
 488 
 
'HE 
 
 THEORY (MATHEMATICAL) EXPLAINED. 
 
 THE 
 
 apart this first partial result, which 
 represents the first term of the 
 formula. 
 
 Add again to unity the number 
 5, and by that sum divide the 
 number a. 
 
 Similarly add to the number 
 2736 the number/, and multiply 
 the sum by the last found quotient ; 
 and set apart this partial result, 
 which represents the second term 
 of the formula. 
 
 Finally, from the first partial re- 
 sult subtract the second, and the 
 difference will be the quantity a r 
 sought. 
 
 Performing these different ope- 
 rations with the values of S, a, 5, r, 
 and/, given above, and supposing 
 the case wherein the letter v has 
 the value t> = 300, you find that 
 the quantity a r will have for its 
 definitive value 
 
 ar =4146. 
 III. If we have the formula 
 
 6-6075 + -002415 
 
 v a 
 10000 
 
 it will amount to the following 
 arithmetical explanation : 
 
 To the number 1 add the num- 
 ber 5, and multiply the sum by the 
 number r. 
 
 To this product add the number 
 /, and multiply the resulting sum 
 by the number -002415. 
 
 To the latter product add the 
 number 6*6075, and keep apart this 
 partial result, which expresses, in 
 one number, what proceeds from 
 all the operations comprised in the 
 great parenthesis. 
 
 Then multiply the number a by 
 the number v, and divide the pro- 
 duct by the number 10000, which 
 will give you another partial result, 
 expressing the portion of the for- 
 mula situated beyond the paren- 
 thesis. 
 
 Finally, multiply the former par- 
 tial result by the latter, and the 
 
 489 
 
 definitive product will be the re- 
 quired value of S. 
 
 For the values above attributed 
 to the different letters contained in 
 the formula, the result of the cal- 
 culation will give S = -67. 
 
 IV. If we have the formula 
 
 S 10000 
 
 a 1-492 + -002415 P 
 
 it will be paraphrased as follows : 
 
 Multiply the number -002415 by 
 the number P, and add to the pro- 
 duct the number 1-492; divide the 
 number 10000 by the sum thus 
 obtained, and write the quotient 
 apart. 
 
 Then divide the number S by 
 the number <z, which will give a 
 second quotient. 
 
 Finally, multiply the former quo- 
 tient by the latter, and the result- 
 ing product will be the required 
 value of v'. 
 
 With the values already indi- 
 cated for the letters, and, more- 
 over, for P = 9360, the result of 
 the preceding formula will give 
 v' = 176. 
 
 V. In fine, as a last example, we 
 will suppose the formula 
 
 It plainly will signify as follows : 
 
 From the number P deduct first 
 the number /, and again from the 
 remainder deduct the number 2118. 
 
 Then to the number 1 add the 
 number 5, and divide the number a 
 by the sum thus obtained. 
 
 Finally, multiply this quotient 
 by the difference before obtained, 
 and the definitive product thus 
 formed will be the required value 
 of a /. 
 
 The operations thus indicated 
 would, for the case wherein the 
 letters should have the values al- 
 ready given above, produce for the 
 required value of a r' the quantity 
 9777. 
 
 Thus we see how easy it is to 
 
THE 
 
 TIDE. 
 
 TID 
 
 replace all the formulae bf their 
 expressions in words ; and, conse- 
 quently, the sight of algebraic for- 
 mulae ought in nowise to intimi- 
 date persons unfamiliar with al- 
 gebra. 
 
 Theotheca, Monstrance, or Remon- 
 strance, sacrament-house in the Ro- 
 man Catholic Church (the pix), the 
 receptacle of the consecrated host, 
 made generally of the most costly 
 materials, and, in some cases, of 
 expensive and beautiful design. 
 Two magnificent examples are 
 given in the ' Divers Works of 
 Early Masters.' The sacrament- 
 house in the church of St. Law- 
 rence at Nuremberg, date 1510, is 
 64 feet in height ; and another, in 
 the church of St. George at Lim- 
 bourg, is upwards of 30 feet high. 
 
 Thermometer, an instrument used for 
 measuring the degrees of heat. (See 
 Temperature of different Thermo- 
 meters.} 
 
 Thesaurus (Greek), a treasure-house. 
 That buildings of this description 
 were required, especially by kings 
 and states, in the earliest period of 
 civilization, is self-evident ; and 
 tradition points to subterranean 
 buildings in Greece, of unknown 
 antiquity and of peculiar formation, 
 as having been erected during the 
 heroic period, for the purpose of 
 preserving precious metals, arms, 
 and other property. 
 
 Thole, a term used in building : the 
 scutcheon or knot in the midst 
 of a timber vault ; also a place in 
 temples where donaries (gifts) were 
 hung up. 
 
 Tholobate, a cupola, and a base: 
 that part of a building on which a 
 cupola is placed. 
 
 Tholus, an appellation given to all 
 buildings of a circular form. Vi- 
 truvius uses it to signify the roof 
 of a circular building. 
 
 Thowl, a piece of timber by which oars 
 are kept in their places in rowing. 
 
 Throat, in ship-building, the hollow 
 part of knee-timbers. 
 
 Throttle-valve, a valve in the steam- 
 
 pipe of an engine, for regulating 
 the supply of steam to the cylinder. 
 In land engines it is generally con- 
 nected to a governor. 
 
 Thucydides informs us, that the 
 Athenians were first among the 
 Greeks to lay aside the custom of 
 bearing arms, and to cultivate ease 
 and luxury (Gladstone). 
 
 Thurible, a censer used in some of the 
 services of the Roman Catholic 
 Church, made usually of metal, in 
 the form of a vase. 
 
 Thurl, a long adit in a coal-pit. 
 
 Thymele, in antiquity, a sort of altar, 
 surrounded with steps, placed in 
 front of the Greek stage or or- 
 chestra. 
 
 Thyrorea, the doors of a Greek tem- 
 ple or house. 
 
 Thyroreum, a passage in the houses 
 of the Greeks, at one end of which 
 was the entrance from abroad, and 
 at the other the doorway leading 
 to the peristyle. 
 
 Tiara, an ornament for the head, an- 
 ciently used by the Persians. 
 
 Ticketinys, the weekly sales of ores. 
 The adventurers or their agents 
 meet together at noon, and whilst 
 sitting round a table, each buyer 
 gives in his ticket, offering a cer- 
 tain sum per ton for so many tons 
 of ore. The tickets are then read 
 aloud by the chairman, and the 
 persons present note the prices 
 offered, the lots or different samples 
 being sold to the highest bidder. 
 
 Tide, the natural fluctuation of the 
 water of the sea and some rivers, 
 whereby it increases and diminishes 
 its quantity at particular times and 
 places, the first being called the 
 tide of flood, the last the tide of 
 ebb : when the tide or flow of water 
 runs against the wind, it is called 
 a windward tide, in which case the 
 sea breaks most, and runs highest. 
 
 Tide-gauge. The merit of this in- 
 vention is due to Mr. Meik, the 
 engineer of Sunderland Harbour, 
 whose attention had been for some 
 time directed to the necessity of 
 having conspicuous tide - gauges 
 
ID 
 
 TIDE-GAUGE. 
 
 TID 
 
 erected at all harbours and docks. 
 Entrusted with the management of 
 a tidal harbour with an intricate 
 and narrow channel, and where 
 frequently from 150 to 200 sail of 
 vessels entered or quitted during a 
 single tide, he perceived that the 
 number of vessels that could safely 
 depart on their outward voyage 
 depended not only on the extent 
 of each tide, but also on the know- 
 ledge of those in charge as to the 
 rate of its flow, by which alone 
 they would be enabled to form a 
 correct judgment as to the suffi- 
 ciency of water to enable the ves- 
 sels to proceed to sea. 
 
 It was evidently essential that 
 any tide - gauge for this purpose 
 should be rendered intelligible to 
 seamen of all grades, and so situ- 
 ated as to be seen from all vessels 
 in time to allow the course of those 
 outward bound to be checked, 
 should there not be sufficient depth 
 of water to enable them to pass 
 over the bar ; or should the vessel 
 be inward bound, and the depth in- 
 dicated by the gauge proved insuf- 
 ficient, she might be brought up, 
 or put off again to sea ; also if the 
 vessel was at anchor in the road- 
 stead, the captain on board should 
 be able to know, from prominent 
 characters,the earliest timeat which 
 he could take the harbour. 
 
 The first port provided with a 
 regular set of signals for this pur- 
 pose was that of Leith. The 
 signals used there are very com- 
 plete, and, with the assistance of a 
 careful man to work the system 
 according to the rise of the tide, 
 are of essential benefit to the ship- 
 ping. But few seamen pay suf- 
 ficient attention to matters of this 
 kind to carry in their memory the 
 exact depth of water corresponding 
 to the signals shown ; and before 
 the book is consulted, the vessel 
 may be driven on the shore, or 
 stranded on the bar. 
 
 The signals at Leith, although 
 perfect of their kind, are used 
 
 4Q1 
 
 only during the day ; while it is 
 evident that night is the time when 
 they are most required by sea- 
 men, to inform them of the state 
 of the tide. By day they generally 
 have some imperfect mode of ar- 
 riving at the depth of water, by 
 observing when the tide reaches 
 certain points on shore, or covers 
 some known rocks at sea ; but at 
 night they cannot guess at the 
 tidal flow even by such inaccurate 
 means, and consequently the gauge- 
 marks or figures should have the 
 property of being clearly distin- 
 guished at night as well as by day, 
 otherwise little advantage will be 
 gained, nor will the loss of life be 
 materially lessened. 
 
 From these considerations, and 
 for the purpose of exhibiting the 
 advantages to be derived from 
 their adoption at the different 
 ports, a self-acting tidal gauge, 
 combining the above - mentioned 
 properties, as far as relates to out- 
 ward-bound ships, has been erected 
 at Sunderland Harbour, by Mr. 
 Meik, in conjunction with Mr. Wat- 
 son, of Newcastle. 
 
 The construction of the gauge is 
 as follows : A well, carefully boxed 
 in, and of similar depth to the 
 water on the bar, is sunk below the 
 building which contains the appa- 
 ratus. Within this well, in an in- 
 terior pipe or trunk, and rising and 
 falling with the tide, works a float 
 suspended by a copper wire cord, 
 which is carried over a spiral cone 
 fixed in an upper story of the build- 
 ing. By the simple arrangement 
 of a wheel and pinion at the oppo- 
 site end of the axle to which the 
 cone is fixed, a web of wire gauze 
 works on two rollers fixed at the 
 upper and lower ends of the web. 
 The lower roller is regulated by the 
 movement of this wheel and pinion ; 
 the upper one by a balance-weight 
 attached to a copper wire cord, 
 which also passes over another 
 spiral cone, having at the extremity 
 of its axle a second wheel and 
 
TID 
 
 TIE-BEAM. 
 
 pinion similar to the first. Jfs the 
 float rises and falls with the tide, 
 the wheels and pinions connected 
 with the cones, over which the 
 cords of the float and balance- 
 weight respectively pass, move the 
 rollers on which the gauze web 
 travels. On this web are painted 
 in large figures the various depths 
 from high to low water, and as the 
 web works, two fixed pointers in- 
 dicate the number of feet and half- 
 feet on the bar at any hour of the 
 tide. 
 
 The web and the figures on it 
 can be made of any size, and to 
 travel 4, 6, 8, 10, or any other pro- 
 portion to 1 of the float, by regu- 
 lating the size of the wheels and 
 pinions. By day the figures on the 
 web are shown white on a black 
 ground; by night they appear dis- 
 tinctly lighted up, the ground still 
 remaining dark. A white trans- 
 parent varnish is used for the 
 figures, and an opaque black for the 
 ground. The illumination by night 
 is so steady and powerful, that the 
 figures, if made large enough, and 
 the apparatus fixed at a sufficient 
 elevation, are visible at a con- 
 siderable distance at sea, and thus 
 afford vessels the means of knowing 
 the exact depth of water at the 
 mouth of any harbour before enter- 
 ing it. This simple piece of me- 
 chanism is applicable to all places 
 where the want of a correct and 
 conspicuous gauge has been felt, 
 not only in harbours and dock's, 
 but at railway stations, for signals 
 and such-like purposes. The appa- 
 ratus used occupies so little space, 
 that it can all be contained and 
 worked in a column or pillar, with- 
 out any other building. 
 
 In the same building is erected, 
 for the Commissioners of the River 
 Weir, a self-registering tide-gauge, 
 to which it is also intended to fix 
 a barometer. The working of 
 this self-registering gauge, which 
 has for some time been in use at 
 a few other ports, is as follows : 
 
 A pencil is fixed in a rack, which 
 registers the variations of the tide, 
 the time of each change being also 
 marked; and immediately under 
 which is a cylinder. On this is 
 fastened a sheet of paper, properly 
 ruled for the purpose, and of suf- 
 ficient size to receive the variations 
 of the tide, traced by the pencil, 
 for fourteen days. The rack con- 
 taining the pencil is connected with 
 a wheel, over which a copper wire 
 cord passes, having attached to it 
 a float, which works in a well of 
 similar construction to that already 
 described as used for the new tide- 
 gauge. This float and cord move, 
 by the action of the tide, the rack 
 and the pencil in it, and trace the 
 diagram on the paper below. A 
 dial on one side of the rack is 
 worked by the same machinery. 
 and points out as a clock the hours 
 and minutes of the day, and the 
 number of feet from high to low 
 water. 
 
 A time-piece, furnished with a 
 strong minute-hand, gives the re- 
 volving movement to the cylinder 
 on which the paper is rolled, and 
 serves to mark the time of the 
 variations of the tide. The float 
 and wheel, in fact, are the means of 
 showing the depths of water ; the 
 time-piece, the exact hour and mi- 
 nute of each change of tide. 
 
 Tie-beam, a beam which acts as a 
 string or tie, to hold together two 
 things which have a tendency to 
 spread apart. 
 
 Tie-rod, a wrought-iron bar or rod 
 for bracing together the frames of 
 steam-engines, roofs, etc. 
 
 Tierce, a vessel containing forty-two 
 gallons, or the third part of a 
 pipe. In the Romish Liturgy, it 
 is one of the canonical hours for 
 prayers, viz. eight in the winter, 
 and ten in the summer, at night. 
 At cards, it is a sequence, or three 
 following cards of one sort. In 
 heraldry, it is the division of a 
 shield into three equal parts. 
 
 Ties, in navigation, the ropes by which 
 
TIG 
 
 TIN. 
 
 TIN 
 
 the yards hang; in mechanics, 
 tension rods. 
 
 Tigna, the principal timbers of a roof 
 extending across ancient temples, 
 in contradistinction to the trahes, 
 which were timbers placed upon 
 the columns or walls in the same 
 direction with them. The tigna 
 correspond to our tie-beams. 
 
 Tiles, baked clay in thin plates of 
 different shapes, used tocover roofs. 
 Tiles curiously and richly orna- 
 mented were formerly used in the 
 early Christian churches for pave- 
 ments. 
 
 Tiller, a piece of timber fitted into the 
 head of a rudder, to which it forms 
 a handle. 
 
 Tilt-hammer. The most simple ma- 
 chine by which iron is forged is 
 the German forge-hammer, often 
 called the tilt-hammer. This ma- 
 chine, often of a fanciful form, is 
 very extensively employed. The 
 leading principle sought in its con- 
 struction is solidity ; and various 
 forms have been invented to give 
 permanency to the structure, which 
 is mainly endangered by the action 
 and re-action of the strokes. The 
 cast - iron tilt - hammer varies in 
 weight, according to the purposes 
 for which it is designed, from 50 
 to 400 pounds. For drawing small 
 iron and nail rods, a hammer of 
 the former size is sufficiently heavy ; 
 but for forging blooms of from 60 
 to 100 pounds in weight, a ham- 
 mer weighing 300 or 400 pounds 
 is employed. Such a hammer 
 should be cast from the strongest 
 grey iron, and secured by wooden 
 wedges to the helve. 
 
 Timber-man, in mining, the man em- 
 ployed in placing supports of tim- 
 ber in the mine. 
 
 Timbers, in ship-building, the ribs 
 which branch outwards from the 
 keel in a vertical direction. 
 
 Timber -framed roofs. Timber - 
 framed roofs occur in the great 
 halls of castles and palaces. Those 
 at Westminster, Christchurch (Ox- 
 ford), and Hampton Court, are 
 
 scarcely inferior in beauty and 
 constructive skill to stone vaults. 
 (Ball. p. 41.) 
 
 The fashion of timber-framed 
 roofs originated about the reign of 
 Edward III., as applied to great 
 halls. They are common about 
 1400 in churches, to which the 
 stone vaulting prior to that date 
 seems to have been peculiar. The 
 first Norman castles had arches of 
 stone in their halls, as had all those 
 built by Edward I. in North Wales.. 
 (Ibid.) 
 
 The skill in construction is ac- 
 knowledged to be great in the tim- 
 ber roofs alluded to, but none of 
 them can vie with the best exe- 
 cuted roofs of stone in beauty. All 
 the tracery and carving which I 
 have seen in timber roofs are 
 clumsy, ill-formed, and unhand- 
 some. The effect was sometimes 
 grand, but never elegant. The 
 effect of time also on the material 
 produces cracks and chasms, which 
 offend as much as ill workman- 
 ship, and indeed destroy that which 
 was once good. In stone the 
 softening of the edges and slight 
 mutilations adds richness and va- 
 riety without injury to the repu- 
 tation of the workman, because 
 enough usually remains perfect to 
 attest his skill and taste. 
 
 Timbers inthehead, in ship-building, 
 pieces with one end bearing on the 
 upper cheeks, and the other ex- 
 tended to the main rail of the 
 head. 
 
 Timbers of ermine, a term in armoury 
 or blazon ; the rows or ranks of 
 ermine in noblemen's capes. 
 
 Tin. This very useful metal is found 
 in small round lumps, in the beds 
 of some rivers near the mines, the 
 principal of which are in Cornwall, 
 but it is generally in nature as 
 an oxide, though occasionally as a 
 sulphate, and associated with many 
 other metals. Tin is a silvery white 
 metal, with a very slight shade of 
 yellow : the purest is the grain-tin, 
 which is prepared from what is 
 
TIN 
 
 TOOLS. 
 
 TOO 
 
 found in the river-beds, and known 
 as stream-tin, and is judged by its 
 splitting when a mass is heated till 
 it is brittle and allowed to fall from 
 a height. It is very malleable and 
 soft : it dissolves in hydrochloric 
 acid, evolving hydrogen gas : nitric 
 acid converts it into a hydrated 
 binoxide. 
 
 Tin, oxide of. When tin is digested 
 in strong nitric acid, a whitish 
 powder is deposited, which, after 
 being washed, and subsequently 
 fused and pulverized, is known in 
 the arts under the term puffy- 
 powder, and is used for polishing 
 glass, stones, etc. 
 
 Tin white resembles zinc white in 
 many respects, but dries badly, and 
 has even less body and colour in 
 oil, though superior to it in water. 
 It is the basis of the best white in 
 enamel painting. There are various 
 other metallic whites of great body 
 and beauty, such as are those of 
 bismuth, antimony,quicksilver, and 
 arsenic ; but none of them are of 
 any value or reputation in painting, 
 on account of their great disposition 
 to change of colour, both by light 
 and foul air, in water and oil. 
 Tincture, a staining or dyeing; also 
 a term in heraldry, signifying a 
 variable hue of arms. 
 Tinsel, a kind of cloth composed of 
 silk and silver, glistening like stars 
 or sparks of fire. 
 
 Tire, in mechanics, the strong iron 
 hoop that binds the circumference 
 of a wheel. 
 
 Tires, of locomotive engines, the out- 
 side hoops round the wheels, gene- 
 rally with a flange to keep arid 
 guide them on the rails. Stephen- 
 son's patent engine and eight- 
 wheeled engines are usually made 
 without flanges on the tires of the 
 driving wheels. Some tires are 
 steeled on the part subjected to 
 most wear, which renders them 
 more durable. 
 
 Titanate of iron (Titaniferous iron, 
 Iron sand} is an oxide of iron and 
 titanic acid, and belongs to the class 
 
 494 
 
 of the magnetic oxides. It is at- 
 tracted by the magnet, is of a deoj 
 black colour, metallic lustre, ver\ 
 hard, and perfectly opaque ; melts 
 into a black slag by a high tem- 
 perature. It is generally found 
 near volcanoes or- volcanic rocks, 
 but seldom in quantities sufficient 
 to justify the erection of iron- 
 works ; nevertheless the quality is 
 mostly good, and the volcanic re- 
 gions aiound the lakes of America 
 may present, in the course of time, 
 encouraging prospects. 
 Titanium. This metal is found oc- 
 casionally in the slag of smelting- 
 furnaces, in small cubical crystals 
 of a copper colour: it exists in 
 anatase, and several varieties of 
 titanate of iron, but combined with 
 oxygen. 
 
 Ton, a weight which varies in dif- 
 ferent districts : the common ton 
 is 20 cwts. of 112 Ibs., or 2240 Ibs. ; 
 in Cornwall the miner's ton is 21 
 cwts. of 112 Ibs., or 2352 Ibs. 
 Tontine, a term derived from the name 
 of the inventor, Lorenzo Tonti, a 
 native of Naples, who originated the 
 scheme so called, first adopted in 
 1653 in France. The subscribers 
 were divided into ten classes, ac- 
 cording to their ages, or were al- 
 lowed to appoint nominees, who 
 were so divided ; and a proportion- 
 ate annuity being assigned to each 
 class, those who lived the longest 
 had the benefit of their survivor- 
 ship, by the whole annuity being 
 divided amongst the diminished 
 number. Some remarkable cases 
 have occurred in England : a ton- 
 tine of a recent date consisted of 
 a less number than ten members, 
 all of whom, with the exception 
 of one, died within a very few 
 years from the commencement, 
 leaving this survivor in the receipt 
 of an enormous sum of money 
 annually, derivable from the pro- 
 fits of the undertaking, which are 
 unvarying. 
 
 Tools, instruments employed in the 
 manual arts for facilitating mecha- 
 
:oo 
 
 TOOLS. 
 
 TOO 
 
 nical operations, namely, hammers, 
 punches, chisels, axes, adzes, planes, 
 saws, drills, files, etc., by means of 
 percussion, penetration, separation, 
 and abrasion of the substances ope- 
 rated upon ; for all of which ope- 
 rations various motions are required 
 to be given either to the tool or to 
 the work. In handicraft work the 
 tool receives motion, but in self- 
 acting or automatic tools, motion 
 may be given to either. In the 
 case of the turning lathe, the tool 
 remains fixed, and the object moves. 
 In that of the planing machine, the 
 tool may remain fixed, or be made 
 to move according to the duty re- 
 quired to be performed. In almost 
 all other machines, such as the 
 slotting, the key-grooving, the 
 punching, the drilling, the nut- 
 cutting, the teeth of wheels cutting, 
 the boring, the screw-cutting ma- 
 chines, the tools receive motion. 
 In the screw*, bolt, and nut machines 
 the tool is either movable or fixed. 
 The use of handicraft tools is coeval 
 with the earliest periods of anti- 
 quity, and the recent researches of 
 modern travellers have proved the 
 ancients to have been acquainted 
 with almost all the tools now in 
 use. The potter's wheel, the axe, 
 the chisel, the saw, etc., attest the 
 perfection to which the mechanical 
 arts were carried by the Greeks 
 and Romans ; and subsequently in 
 the arts of turning exhibited by the 
 Dondi family, in the construction of 
 their clocks and of machines for 
 spinning silk, in the middle of the 
 13th century, in Italy, and after- 
 wards by Bessoni, De la Hire, De 
 la Condamine, Grand Jean, Plu- 
 mier, and Morin. The three plates 
 of Bessoni show the different modes 
 of turning and cutting screws of 
 all sorts of fancy work. De la Hire 
 shows how all sorts of polygons 
 may bfe made by the lathe, and 
 Condamine shows how a lathe may 
 be made to turn all sorts of irre- 
 gular figures by means of tracers 
 moved over the surface of models 
 
 and sculptures, medals, etc. ; and 
 this is perhaps the first idea of the 
 machine called the Tour a Por- 
 trait. 
 
 The work of Plumier enters most 
 extensively into the art of turning, 
 for he shows the construction of 
 the lathe and its different parts, 
 the art of making, hardening, tem- 
 pering, and sharpening tools, the 
 different kinds of motions which 
 may be given to the lathe by means 
 of wheels, eccentrics, and models, 
 and the different inventions relative 
 to works of art which have been 
 performed by the lathe, among 
 which may be mentioned the mov- 
 able or slide rest. In the common 
 rest which supports the tool, the 
 idea of fixing the tool and pushing 
 it in the direction of the parallel 
 bed of the lathe, so as to cause the 
 tool to traverse the work parallel 
 to it, must have been obvious; and 
 as this could have been easily ef- 
 fected by means of the screw and 
 handle, it required little ingenuity 
 to carry out the idea to its fullest 
 extent, by constructing a rest to 
 allow of the slide traversing the 
 horizontal or vertical plane in any 
 direction. The machine described 
 by Plumier is neither more nor 
 less than the slide-rest and planing 
 machine combined : it consists of 
 two parallel bars of wood or iron 
 connected together at both extre- 
 mities by bolts or keys of sufficient 
 width to admit of the article re- 
 quired to be planed : a movable 
 frame being placed between the 
 two bars, and motion being given 
 to it by a long cylindrical thread, 
 is capable of giving motion to any 
 tool which may be put into the 
 sliding frame, and consequently 
 either causing the screw, by means 
 of a handle at each end of it, to 
 push or draw the point or cutting 
 edge of the tool either way. If 
 also motion be given to the tool by 
 means of guides upwards or down- 
 wards, it is evident that any kind 
 of reticulated form can be given to 
 
 495 
 
 Y 2 
 
TOO 
 
 TOOLS. 
 
 TOO 
 
 the work, as in the machine de- 
 scribed by Plumier, which was in- 
 tended for ornamenting the handles 
 of knives, and which is called by 
 Plumier, Machine a Manche de 
 Couteau d 1 Angleterre, from its 
 having been an English invention. 
 The Machine a Canneler, described 
 by Bergeron, a mode of grooving 
 columns, is probably derived from 
 the same source, from its resem- 
 blance to the English machine. 
 The origin of the planing machine, 
 in more recent times, is said to 
 have arisen from the grooving or 
 fluting of the drawing rollers used 
 in cotton machines, shortly after 
 the introduction of Arkwright's in- 
 ventions. The patent of Sir Samuel 
 Bentham in 1793, for various new 
 methods for working wood, metal, 
 and other materials, certainly con- 
 templates the working of tools 
 similarly to the tools employed 
 in the planing machine, as it 
 comprehends giving all sorts of 
 motion to tools : and the patent of 
 Joseph Bramah, taken out in 1802, 
 was " for machinery for producing 
 straight, parallel, and smooth sur- 
 faces and other materials requiring 
 truth, in a manner more expe- 
 ditious and perfect than can be 
 performed by the use of axes, 
 screws, planes, and other cutting 
 instruments used by hand in the 
 usual way." 
 
 Billlngsby, of Birkenshaw, took 
 out a patent in 1802, for boring 
 cylinders in a vertical position, al- 
 though horizontal machines had 
 their advantages. The boring of 
 large cylinders by horizontal ma- 
 chines had long been practised by 
 Smeaton,\Vilkinson,Walker, Darby, 
 and Boulton and Watt, and at But- 
 terley and other great iron-works ; 
 but it was many years subsequently 
 that the vertical boring machines 
 came into use. 
 
 As respects the introduction of 
 the first planing machines which 
 have been used during the present 
 century ,4 opinions are at variance. 
 
 "496 
 
 Messrs. Fox, of Derby, the eminent 
 tool-makers, state that the first ma- 
 chine employed for this purpose 
 was constructed by Mr. Fox, senior, 
 in the year 1821, for the purpose 
 of planing the wrought and cast 
 iron bars used in the lace machines: 
 the machine was capable of planing 
 an article 10 feet 6 inches in length, 
 22 inches in width, and 12 inches 
 in depth : others give the credit of 
 the invention to Manchester, and 
 G. Rennie, Esq., puts in a claim 
 for constructing a planing machine 
 with a movable bed, urged by an 
 endless screw and rack, and fur- 
 nished with a revolving tool, so 
 early as 1820, having several years 
 previously employed the principle 
 for grooving and planing parallel 
 bars. 
 
 Mr. Bramah, in 1811, employed 
 the revolving cutter to plate-iron. 
 Mr. Clement states that he made a 
 planing machine, for planing the 
 sides of weaving looms and the tri- 
 angular bars of lathes previously to 
 1820. He afterwards constructed 
 a beautiful machine for planing 
 large and small work with the 
 greatest accuracy. The bed moved 
 on rollers, and the tools cut both 
 ways. The beautiful work exe- 
 cuted by this tool , for Mr. Babhage's 
 calculating machine, evinces the 
 perfection of its performance. It 
 is thus by the aid of automatic 
 tools that the greatest precision and 
 identity of parts in machinery is 
 produced; and it is probable that, 
 ere long, the chisel, the file, and the 
 grindstone will be banished from 
 the factory, and that nicety of parts 
 and uniformity and silence of ac- 
 tion, blended with the science of 
 construction, will eventually super- 
 sede the expensive and imperfect 
 construction of the handicraft sys- 
 tem. Subsequently very important 
 tools have been invented by Mr. 
 Joseph Whitworth, of Manchester. 
 For the slide-rest and other tools 
 see second edition of ' Rudimentary 
 Mechanism.' 
 
00 
 
 TRACERY. 
 
 TKA 
 
 n oon wood is of a reddish -brown 
 colour, rather coarse-grained, much 
 used all over India for furniture 
 and cabinet-work. 
 
 n op and But, in ship-building, the 
 general method of working the 
 English plank (except in the top- 
 side) to make good work and con- 
 version, which is by disposing- of 
 the top-end of every plank within 
 6 feet of the but-end of the plank 
 above or below it, leaving all the 
 planks to work as broad as. possible, 
 so that every other seam is fair. 
 
 Fop-timbers, in ship-building, the up- 
 permost timbers : the first general 
 tier of timbers that reaches the top 
 of the side are, or should be, called 
 top-timbers ; those which scarf on 
 the heads of the upper futtock are 
 called short timbers. 
 
 Torricellian tube, in pneumatics, a 
 glass tube named after the inventor, 
 open at one end and hermetically 
 sealed at the other. 
 
 Torricellian vacuum. This is pro- 
 duced by filling a tube with mer- 
 cury, and allowing it to descend to 
 such a height as to be counter- 
 balanced by the pressure of the 
 atmosphere, as in the barometer. 
 
 Torsion is that force with which a 
 thread of wire returns to a state 
 of rest after it has been twisted by 
 being turned round on its axis. 
 
 Torsion-electrometer, an apparatus 
 for measuring the intensity of elec- 
 tricity. 
 
 Torus, the convex member of tLe 
 Tuscan and Ionic bases. In the 
 attic base there is both an upper 
 and lower torus. 
 
 Tossing, Tozing, or Terloobing, a pro- 
 cess consisting in suspending ores 
 by violent agitation in water : their 
 subsidence being accelerated by 
 packing, the lighter and worthless 
 matter remains uppermost. 
 
 Tower, an ancient elongated vertical 
 building, variously formed and con- 
 structed in different countries. 
 
 Town Hall, Mansion House; in France, 
 Hotel de Ville; in Italy, Palazzo 
 Publico ; in Holland, Stadhaus ; an 
 
 edifice in which all the municipal 
 laws and regulations and the inter- 
 ests of a city are conducted. 
 Tracery, that species of pattern-work 
 formed or traced in the head of a 
 Gothic window by the mullions be- 
 ing continued, but diverging into 
 arches, curves, and flowing lines 
 enriched with foliations. 
 
 " Each country," says Mr. Gar- 
 bett in his ' Rudimentary Treatise 
 on the Principles of Design in 
 Architecture,' " has had its succes- 
 sive styles of tracery, and each has 
 begun with the simple subdivision 
 of one arch into two, and these 
 sometimes into two again, filling 
 up the space between the heads 
 with a circle, as at Marburg; a 
 foiled circle, as at Salisbury chap- 
 ter-house, and the aisles of Co- 
 logne ; or finally a foil-circle, as 
 at Westminster, and the clerestory 
 of Cologne, where it is subfoiled: 
 thence proceeding to pack together 
 such forms over an odd number of 
 lights, to which the method of con- 
 tinual bisection would not apply, 
 as at the aisles of York ; and thus 
 the first kind, which may be called 
 packed tracery, became complete. 
 Deviations from the principle of 
 packing led to the general tracery, 
 absurdly called 'geometrical? for 
 all Gothic tracery is geometrical, 
 none is hand-drawn. This beauti- 
 ful purely unmeaning tracery was 
 succeeded in all countries by the 
 flowing loop or leaf, and then by 
 the peculiar national After-Gothic. 
 Germany, however, as it had been 
 the first to perfect, was also the 
 last to abandon the ' geometrical ' 
 tracery, which continued there, 
 even into the fifteenth century, our 
 Perpendicular Period. England and 
 France, however, in the fourteenth 
 century, abandoned the unmeaning 
 for the flowing leaf-tracery ; and 
 this, notwithstanding its beauty, 
 had hardly time to show itself be- 
 fore it was superseded, here by the 
 perpendicular, and in France by the 
 flamboyant. Hence it happens that 
 
 497 
 
TRA 
 
 TRACERY. 
 
 TRA 
 
 of the three great classes of tnfcery, 
 geometrical, flowing and perpen- 
 dicular, while the last is, as every- 
 one knows, by far the commonest 
 in England, the most ahundant kind 
 in France is flowing (flamboyant), 
 and in Germany geometrical, i. e. 
 unmeaning. 
 
 " The unmeaning tracery of Ger- 
 many is very beautiful, and gene- 
 rally partakes of the packed cha- 
 racter ; the following forms, which 
 are the elements of German tracery, 
 occurring very abundantly. 
 
 Elements of German tracery. 
 
 " The convex-sided triangle and 
 square are placed in all positions in- 
 differently, and the frameless tre- 
 foils and quatrefoils are frequently 
 formed on the basis of these figures 
 instead of the circle. The foil- 
 ings and subfoilings, formed by a 
 very narrow but deep chamfered 
 member, leave their little spandrils 
 (called eyes by our workmen) en- 
 tirely open, thus producing almost 
 the lightness of metal-work. 
 
 " The Germans seized on the idea 
 of growth, and the budding and 
 sprouting expression ; but perhaps 
 the French were most successful in 
 increasing the aspiring expression : 
 by a slight change in the prevail- 
 
 ing forms of the flowing tracery, 
 they converted the loops or leaves 
 into flame-like forms, till the 
 flamboyant buildings appeared not 
 vegetating, as in Germany, but 
 blazing from the foundation to the 
 bristling finials. The difference be- 
 tween this style of tracery and our 
 own flowing style (exemplified in 
 the west window at York), is, that 
 
 English leaf-tracery. 
 
 while the upper ends of our loops 
 or leaves are round or simply 
 pointed, t. e. with finite anylr.s, the 
 upper ends in France terminate, 
 like the lower, in angles of contact 
 (those formed by two curves that 
 have a common tangent). It was 
 necessary to the leafy effect that 
 the lower angles should be tan- 
 gential ; but to the flame-like ef- 
 fect, that the upper ones should 
 be so, even if the lower were 
 
 French flamboyant tracery. 
 
 finite; and hence some examples 
 of flamboyant tracery, if turned 
 
 498 
 
TRA 
 
 TRACTION. 
 
 TRA 
 
 upside down, form a kind of leaf- 
 tracery. 
 
 " Our countrymen, however, 
 adopted a method which was less 
 conducive to the aspiring expres- 
 sion, and which conducted them to 
 a style less rich and certainly less 
 
 varied than any of the other After- 
 Gothics. Erroneously supposing 
 that an ahundance of vertical lines 
 would increase this character, they 
 were led to convert all the flowing 
 lines of the window tracery into 
 vertical ones, to omit the capitals 
 of nearly all the smaller shafts 
 or shaftlets, thus converting what 
 had been blank arcades into mere 
 panels, and then to multiply, di- 
 minish, and extend these panels 
 and endless repetition of vertical 
 lines over every part of the inte- 
 rior, and, in florid buildings, even 
 of the exterior." 
 
 Traction, in mechanics, is the act of 
 drawing a body along a plane, 
 usually by the power of men, ani- 
 mals, or steam; as when a vessel 
 is towed on the surface of water, 
 or a carriage moved upon a road. 
 The power exerted in order to pro- 
 duce this effect is called the force 
 of traction. 
 
 Numerous experiments have been 
 made for the purpose of ascertain- 
 ing the value of a force so exerted ; 
 and when men are employed to 
 draw laden boats on canals, it is 
 found that if the work be continued 
 for several days successively, of 
 eight hours each, the force of trac- 
 tion is equivalent to a weight of 
 31^ Ibs. moved at the rate of 2 feet 
 
 499 
 
 per second, or 1-| mile per hour (it 
 being understood that such weight 
 is imagined to be raised vertically 
 by means of a rope passing over a 
 pulley, and drawn in a horizontal 
 direction). The force of traction 
 exerted when, without moving from 
 his place, a man pulls horizontally 
 against a weight so suspended, is 
 estimated at 70 Ibs. The action of 
 a horse in drawing a vessel on a 
 canal is said to be equivalent to a 
 weight of 180 Ibs. raised vertically, 
 as above supposed, with a velocity 
 of 3 feet per second, or 2 miles 
 per hour; but this estimate has 
 been considered too high; and from 
 experiments which have been made 
 on the power of horses in waggons, 
 carts, and coaches, on level ground, 
 it is found that the force of traction 
 exerted by a stout horse is equiva- 
 lent to 80 Ibs. raised at the rate 
 of 4 feet per second, or 3 miles 
 per hour. Tredgold considers that 
 a horse exerts a force of traction 
 expressed by 125 Ibs. raised at the 
 rate of 3f feet per second, or 2 
 miles per hour. A man or a horse 
 can, however, double his power of 
 traction for a few minutes without 
 being injured by the exertion ; and 
 when the carriage is in motion, :o 
 that the friction on the ground is 
 alone to be overcome, a horse can 
 draw, during a short time, on a 
 level road, a weight exceeding 
 1500 Ibs. 
 
 The force of traction is found to 
 vary nearly with the term (w w) 2 , 
 where w is the greatest walking 
 velocity of a man or horse when 
 unresisted (6 feet per second, or 4 
 miles per hour, for a man, and 
 10 feet per second, or 6f miles per 
 hour, for a horse), and v is the 
 velocity with which the vessel or j 
 carriage is moved. From theoreti- 
 cal considerations it has been de- 
 termined that the greatest effect is 
 produced when the velocity of the 
 object moved is one-third of that 
 with which the man or animal can 
 walk when unresisted. 
 
TRA 
 
 TRACTION. 
 
 TRA 
 
 If a wheel-carriage were situated 
 on a level plane which opposea no 
 resistance, it is evident that, what- 
 ever were the diameter of the 
 wheels, the smallest conceivable 
 power of traction applied to the 
 axle w r ould suffice to put the car- 
 riage in motion. But when a wheel 
 in moving meets with an obstacle 
 on the ground, that obstacle is 
 pressed at the point of contact by 
 a force acting in the direction of a 
 line drawn to it from the centre of 
 the wheel, and arising from that 
 part of the weight which is sup- 
 ported by the wheel, together with 
 the force of traction; therefore, by 
 the ' resolution of forces,' the ratio 
 between the resistance which is to 
 be overcome by the moving power 
 and the weight on the wheel will 
 become less as the diameter of the 
 wheel is increased: also the most 
 advantageous direction in which 
 the force of traction can be exerted 
 is perpendicular to the line of pres- 
 sure drawn from the centre of the 
 wheel to the obstacle. But the 
 height of the wheels cannot exceed 
 certain limits, depending on the use 
 to which the carriage is applied; 
 and w hen the latter has four wheels, 
 the height of those which are in 
 front must be such only as will 
 allow it to be turned round within 
 a given space : also, when a horse 
 is employed to move a carriage, 
 attention must be paid to the con- 
 ditions under which his power may 
 be advantageously exerted. 
 
 It was first observed by M. De- 
 parcieux, and published in the 
 ' Memoires de I'Academie des Sci- 
 ences,'! 760, that horses draw heavy 
 loads rather by their weight than 
 by their muscular force. Sir Da- 
 vid Brewster has also remarked 
 that when the resistance is great, 
 a horse lifts both its fore-feet from 
 the ground ; then, using his hinder 
 feet as a fulcrum, he allows his 
 body to descend by its weight, and 
 thus overcomes the obstacle : and 
 it may be added, that when this 
 
 action takes place with a two- 
 wheeled carriage, if the loading is 
 disposed so that some portion of it 
 may press on the horse's back, the 
 effect of the animal's weight will 
 thereby be increased. Now, if the 
 traces, or the shafts of the carriage, 
 were attached to the horse's collar, 
 near his centre of gravity, a line 
 imagined to be drawn from the 
 latter point to his hinder feet may 
 represent his weight, and a line 
 drawn perpendicularly from his 
 feet upon a plane passing through 
 the traces or shafts may represent 
 the lever of resistance : but while 
 the former line remains the same, 
 this lever becomes less as the plane 
 of traction (that of the traces or 
 shafts) inclines more upwards from 
 the wheel ; and therefore, in order 
 that the power of the horse may he 
 advantageously applied, the dia- 
 meter of the wheel should be as 
 small as is consistent with other 
 circumstances. 
 
 Experiments have shown that 
 when the angle of traction, as it is 
 called, that is, the angle which the 
 plane of the traces makes with the 
 road on which the carriage is mov- 
 ing, is 15 or 16 degrees, a horse 
 pulls with good effect ; and the 
 height of the points at which the 
 traces are attached to a horse's 
 collar being about 4 feet 6 inches 
 from the ground, it follows that, in 
 order to obtain this inclination, the 
 lower extremities of the traces or 
 shafts should be 2 feet 3 inches 
 from the ground. In general, how- 
 ever, in two-wheeled carriages the 
 height of these extremities is about 
 3 feet. 
 
 As an example of the force of 
 traction exerted by steam, it may 
 be stated, that on a level line of 
 railway, an engine with an 11-inch 
 cylinder, and having an effective 
 pressure of 50 Ibs. per square inch 
 in the boiler, drew 50 tons at the 
 rate of 30 miles per hour, working 
 10 hours daily; and that the same 
 engine, with an equal pressure in 
 
 500 
 
TRA 
 
 TRAVELLER. 
 
 TRA 
 
 the boiler, drew 160 tons at the 
 rate of 15 miles per hour. 
 
 Trail, a running enrichment of leaves, 
 flowers, tendrils, etc., in the hollow 
 mouldings of Gothic architecture. 
 
 Trail-boards, in ship-building, the 
 carved work between the cheeks : 
 that which is fastened to the knee 
 of the head. 
 
 Trailing springs, the springs fixed on 
 the axle-boxes of the trailing wheels 
 of a locomotive engine, which bear 
 slightly against the side frames, so 
 as to leave as much weight as pos- 
 sible upon the driving springs, and 
 to assist in deadening any shock 
 which may take place. 
 
 Trailing wheels, the wheels placed 
 behind the driving wheels of a 
 locomotive engine. 
 
 Trammel, a rod of iron or wood, 
 with sliding pieces having points, 
 which can be fixed at any distance 
 apart ; used for drawing large cir- 
 cles, or setting off distances. 
 
 Transept, the transverse portion of a 
 cruciform church ; that part which 
 is placed between and extends be- 
 yond those divisions of the building 
 containing the nave and the choir. 
 
 Trannit, a term expressing the pas- 
 sage of a railway train, etc. In 
 astronomy, the passage of any hea- 
 venly body over a larger one, as 
 Mercury or Venus over the sun. 
 
 Transition, as applied to the architec- 
 ture of the middle and later ages, 
 the progress of changing from one 
 style to another. There were seve- 
 ral periods of transition : Roman- 
 esque to Saxon, Norman to Early 
 English, Early English to Deco- 
 rated, from the Decorated to the 
 Perpendicular to that of the Tudor 
 and to that of the Elizabethan age. 
 
 Transom, a horizontal mullion or 
 cross-bar in a window. The most 
 ancient examples are found in the 
 Early English style. 
 
 Transom,'m carpentry, a thwart-beam 
 or lintel over a door. In ship- 
 building, certain timbers extending 
 across the stern-post of a ship, 
 to fortify and strengthen it. In 
 
 mathematics, the vane of an in- 
 strument called a cross-staff, being 
 a piece of wood fixed across, with 
 a square socket upon which this 
 slides. 
 
 Transparency, that quality of certain 
 bodies by which they transmit the 
 rays of light, in contradistinction 
 to opacity. 
 
 Transparent and Opaque Colours. As 
 a general proposition, the Homeric 
 colours are really the modes and 
 forms of light, and of its opposite 
 or rather negative, darkness ; par- 
 tially affected perhaps by ideas 
 drawn from the metals, like the 
 ruddiness of copper, or the sombre 
 effect of dead blue, whatever the 
 substance may have been ; and here 
 and there with an inceptive effort, 
 as it were, to get hold of other 
 ideas of colour ; of the transparent 
 and opaque or chiaroscuro, we can- 
 not expect to hear from Homer. 
 (Gladstone, vol. iii. p. 489.) 
 
 Transposition, in music, the changing 
 a tune or lesson, and putting it into 
 a higher or lower key or clef. 
 
 Transtra, horizontal timbers in the 
 roof of a building. The term is 
 applied to the transverse beams of 
 a gallery which extend from side 
 to side and connect the ribs, in the 
 same manner as those horizontal 
 pieces connect the axis or princi- 
 pals of a roof. 
 
 Transverse, in geometry, something 
 that goes across another, from cor- 
 ner to corner, like the diagonals of 
 a square or parallelogram. 
 
 Transyte, a narrow or triforial pas- 
 sage. 
 
 Trapezium, in geometry, a plane 
 figure contained under four right 
 lines, of which neither of the oppo- 
 site sides are parallel. 
 
 Trapezoid, an irregular figure whose 
 four sides are not parallel, resem- 
 bling a trapezium. 
 
 Traveller, in navigation, a sort of 
 thimble, whose diameter is much 
 larger, in proportion to the breadth 
 of its surface, than the common 
 ones:*it is intended to facilitate 
 
RA 
 
 TRIBUNES. 
 
 TRI 
 
 the hoisting and lowering the top- 
 gallant yards at sea. 
 Travelling crane, a crab fixed on a 
 carriage which may be moved upon 
 rails across a building, and the 
 cross-rails, together with the car- 
 riage, moved lengthwise upon other 
 rails fixed at or near the top of the 
 building. 
 
 Traverse sailing, in navigation, is the 
 variation or alteration of a ship's 
 courseoccasioned by various causes ; 
 or it is a compound course in which 
 several different courses and dis- 
 tances are known. 
 
 Traverse-table, in navigation, is the 
 same as a table of difference and 
 departure, ready calculated for any 
 distance under 100 miles. 
 Treadle, a lever or frame connected 
 by a rod to the crank of a foot- 
 lathe, to give motion to the crank- 
 shaft: it is pressed down by the 
 left foot of the turner, and raised 
 by the centrifugal force of the fly- 
 wheel or large pulley which is 
 fixed on the shaft. 
 
 Treasury, a building or an apartment 
 where money or valuables are de- 
 posited. 
 
 Tree-nails or Trennels, in ship- 
 building, long cylindrical wooden 
 pins. 
 
 Trefoil, an ornament formed by 
 mouldings so arranged as to re- 
 semble the trefoil or three-leaved 
 clover. 
 
 Trellis, a gate or screen of openwork ; 
 lattice -work either of metal or 
 wood. 
 
 Trench, a ditch ; a defence for soldiers. 
 Trenches, approaches, or attacks, 
 are works carried on by besiegers, 
 with parapets for the men to gain 
 ground and draw near a citadel or 
 fortification : if the ground be hard 
 or rocky, trenches are raised above 
 it with fascines, bags of earth, etc.; 
 but if the earth can be easily dug, 
 then a ditch or way is sunk, and 
 edged with a parapet next to the 
 besieged, the depth being com- 
 monly about six or seven feet, 
 and the breadth seven or eight feet. 
 
 Trend, in navigation, to bend, to lie 
 in a particular direction. 
 
 Trestle-trees, in ship-building, two 
 strong bars of timber fixed hori- 
 zontally on the opposite sides of 
 the lower mast-head, to support 
 the frame of the top and the weight 
 of the topmast. 
 
 Tret, an allowance in weight for 
 waste or impurities. 
 
 Triangle, a figure bounded by three 
 sides, and consequently containing 
 three angles. Triangles are of the 
 several kinds, plane or rectilinear, 
 spherical, and curvilinear. 
 
 Triboineter, in mechanics, a term 
 applied to an instrument for esti- 
 mating the friction of metals. 
 
 Tribunes, magistrates among the old 
 Romans, chosen to preserve the 
 privileges and secure the liberties 
 of the people against the power 
 and encroachments of the nobles : 
 at first their number was but two, 
 and these afterwards associated 
 three more to them, whose number 
 was in process of time increased to 
 ten. Their authority was so great 
 that they could assemble the people 
 for what purposes they pleased, 
 hinder the deliberations of the se- 
 nate, approve or annul its decrees, 
 summon the other magistrates be- 
 fore the people, and also their own 
 colleagues and associates : they 
 went so far as sometimes to impri- 
 son consuls and fine dictators. At 
 first their jurisdiction reached but 
 a mile out of the city of Rome, but 
 some time afterwards it was ex- 
 tended into the provinces. These 
 officers kept their doors open day 
 and night, to receive such of the 
 common people as sought for shel- 
 ter with them. The office grew 
 into so much authority and honour, 
 that the greatest men in the state 
 chose it, and by clashing with the 
 consuls and senate occasioned great 
 tumults. There were also military 
 tribunes, but their powers were 
 more limited. 
 
 Tribute, in mining, a proportion of 
 the ore which the workman has 
 
TRI 
 
 TROPICS. 
 
 TRU 
 
 for his labour. Tributers gene- 
 rally work in gangs, and have a 
 limited portion of a lode set them, 
 called a ' tribute pitch,' beyond 
 which they are not permitted to 
 work, and for which they receive a 
 certain portion of the ore, or so' 
 much in the pound as agreed upon 
 in value of what they raise. 
 
 Triclinium, the eating-room of a Ro- 
 man house ; so called because in 
 general it contained couches upon 
 which the ancients or their guests 
 reclined at their meals. The term 
 was also applied to the couches 
 themselves. 
 
 Triforium, the gallery or open space 
 between the vaulting and the roof 
 of the aisles of a church, generally 
 lighted by windows in the external 
 wall of the building and opening to 
 the nave, choir, or transept over 
 the main arches. In the Temple 
 church it is built around the nave, 
 and has a curious and singular 
 effect. 
 
 Triglyphs, in architecture, ornaments 
 repeated at equal intervals in the 
 Doric frieze. Each triglyph con- 
 sists of two entire gutters or chan- 
 nels cut to a right angle, called 
 glyphs, and separated by their in- 
 terstices, ca\\edfennona, from each 
 other as well as from two other 
 half-channels that are formed at 
 the sides. 
 
 Trigonometry, the art of measuring 
 triangles, or of calculating the sides 
 of any triangle sought, either plain 
 or spherical. 
 
 Trim, in navigation, the best posture 
 of a ship's proportion of ballast, 
 arrangement of sails, and position 
 of masts, with a view to her sailing 
 well. 
 
 Trimmer, a piece of timber inserted 
 in a roof, floor, wooden partition, 
 etc., to support the ends of any of 
 the joists, rafters, etc. 
 
 Tringle,in architecture, a name com- 
 mon to several little square mem- 
 bers or ornaments, as regulets, 
 lestets, and platbands. 
 
 Tripod, any utensil or article of 
 
 furniture supported upon three 
 feet. 
 
 Triptic, a tablet in three divisions, 
 to open and shut, the two outer 
 folding over the centre one when 
 closed. 
 
 Trisection, the division of a line, an 
 angle, etc., into three equal parts. 
 
 Trochilus, a hollow moulding ; also 
 called scotia ; constantly occurring 
 in the bases of the classical orders 
 of architecture. 
 
 Trochoid, in geometry, a particular 
 description of curve generated by 
 the motion of a wheel. 
 
 Tropics, two lesser circles on the 
 globe or sphere ; one on each side, 
 distant 23i from the equator, 
 which are the bounds or limits of 
 the sun's deviation from the equa- 
 tor : at his approach to these cir- 
 cles the sun seems to stand still 
 for a few days, and then returns 
 towards the equator again : that 
 on the north side is called the 
 tropic of Cancer, and, when the 
 sun is there, makes our longest 
 day ; and that on the south side 
 is called the tropic of Capricorn, 
 and causes the longest night. 
 
 Troubles, in mining, faults or inter- 
 ruptions in the stratum. 
 
 Trucks, in navigation, circular flat 
 pieces of elm, with a small sheave 
 on each side, fixed upon the upper 
 end of flag-staffs, and used to reeve 
 the halliards. 
 
 Truncated, in geometry, a pyramid 
 or cone, the top or vertex of which 
 is cut off by a plane parallel to its 
 base. 
 
 Trunk Engine, a marine steam-engine 
 
 used for driving a propeller: the 
 cylinder is fixed horizontally. 
 
 Trunking, the process of extracting 
 ores from the slimes : the ores sub- 
 sequently undergo the process of 
 racking and tossing. 
 
 Trunnions, knobs of metal in pieces 
 of ordnance which project from 
 the sides and bear the guns on the 
 cheeks of the carriage. 
 
 Truss, the collection of timbers form- 
 ing one of the principal supports to 
 
TRU 
 
 TUBULAR BOILERS. 
 
 TUB 
 
 a roof, framed together to give mu- 
 tual support and to prevent strain- 
 ing or distortion from the super- 
 incumbent weight. 
 
 Truss, to strain, support or keep tight: 
 a trussed roof is one which, by 
 means of the tie-beams, rafters, 
 king-posts, etc., is strained, or held 
 together in its proper position. 
 
 Trussing, in carpentry and ship-build- 
 ing, a series of diagonal braces dis- 
 posed in triangles, the sides of 
 which give to each other a mutual 
 support and counteraction. 
 
 Trussing beds, in Tudor times, were 
 beds which packed into chests for 
 travelling : in cases of frequent re- 
 moval, they must have been found 
 very convenient. John of Ghent 
 seems to have always slept in such 
 beds. 
 
 Tub, a cast-iron cylinder put in the 
 shaft instead of bricking, for the 
 purpose of beating out the water 
 and making it rise to a level. 
 
 Tubes, in locomotive engines, are of 
 brass or iron, about two inches 
 outside diameter. They are of the 
 same length as the boiler, and fixed 
 in it by a ferrule driven in at each 
 end, which makes them steam- 
 tight. They are surrounded with 
 water externally, and internally 
 open to the atmosphere by the 
 chimney. The heated gases and 
 smoke from the fire pass through 
 them, and they are thus the means 
 of rapidly generating steam. The 
 number of tubes in boilers varies 
 from 60 to 70 up to above 200, 
 according to the power of the 
 engine. 
 
 Tube Ferrules, in locomotive engine^ 
 slightly tapered hoops, one of which 
 is driven in at each end of each 
 tube, to fix it securely in the boiler : 
 formerly they were made of steel 
 and iron ; now, cast-iron ferrules 
 are found to answer very well. 
 
 Tube plugs, in locomotive engines, 
 are formed of tapered iron or wood, 
 and used for driving into the end of 
 a tube when burst by the steam. 
 
 Tube plug -ram, in locomotive engines, 
 
 504 
 
 a long rod with a socket end, into 
 which the plug fits, and is thus 
 driven into the burst tube, and the 
 plug-ram withdrawn. 
 Tubular Boilers. Boilers of an an- 
 gular, prismatic, or indeed any but 
 a cylindrical form, or even then 
 if not made of wrought metal, be- 
 come the peculiar seat of danger 
 in high-pressure engines ; and all 
 sorts of safety apparatus, as well 
 for preventing too great a pressure 
 as for avoiding other sources of 
 danger, are but uncertain in their 
 operation, and not to be depended 
 upon. The great object to he sought 
 is so to construct boilers that their 
 explosion may riot be dangerous in 
 its result. 
 
 This condition has been approxi- 
 mated to by the invention and ap- 
 plication of tubular boilers ; but it 
 would seem that these have been 
 suggested rather by the necessity 
 of providing, for many technical 
 purposes, and particularly for steam 
 carriages, boilers of less content 
 and weight, than by the desire 
 of removing or lessening danger 
 from explosion. Tubes should have 
 that form which is best adapted 
 to resist pressure, viz. the cylin- 
 drical. If they are of small dia- 
 meter, of not too great thickness, 
 and of suitable material, they may 
 be made to carry out the before- 
 named principle ; i. e. they them- 
 selves, in case of bursting, \\ill not 
 cause any dangerous consequences 
 to the neighbouring persons or pro- 
 perty. This has been amply proved 
 by experience. 
 
 Unfortunately, however, there 
 are no tubular boilers which satisfy 
 all conditions required. The sub- 
 ject is often mentioned as one of 
 little difficulty, easy of decision, 
 and unencumbered with practical 
 obstacles ; but such is the language 
 only of the prejudiced and the in- 
 experienced. To arrive at the truth, 
 it must be sought with long-con- 
 tinued perseverance, and with no 
 small share of physical knowledge, 
 
PUB 
 
 TUBULAR BOILERS. 
 
 TUB 
 
 as the subject is beset with diffi- 
 culties on every side. 
 
 It becomes a most complex pro- 
 blem to construct a tubular boiler 
 for a large supply of steam, by rea- 
 son of the difficulty of arranging 
 and connecting the great number 
 of tubes it must contain into one 
 convenient whole. The modern 
 English locomotive boilers cannot 
 be legitimately called tubular boil- 
 ers, because they fail altogether in 
 the grand distinguishing quality of 
 all such, namely, the small dia- 
 meter of the generating apparatus : 
 the tubes of these boilers are no- 
 thing more than a splitting-up or 
 subdivision of the fire-tube of the 
 Trevithick steam - carriage boiler. 
 From their greater outer diameter, 
 locomotive boilers do not avoid 
 the evil of the old capacious form, 
 and therefore do not diminish the 
 objection to it : they have also a 
 defect in the close proximity of the 
 tubes to each other, whereby the 
 water space between them is ren- 
 dered too confined, and the heated 
 tubes become liable to be laid bare 
 of water. This circumstance gives 
 the key to the well-known fact, 
 that the tubes become so soon de- 
 stroyed, or at least require con- 
 stant repair, and add to the mischief 
 occasioned by their expansion, 
 through their connection with the 
 end plates of the cylindrical part of 
 the boiler. It is evident that from 
 the passage upwards of the steam 
 formed among the lower tubes, the 
 upper ones must be most liable to 
 be uncovered with water ; while 
 these, being exposed to the hottest 
 part of the fire current, are most 
 likely to receive damage there- 
 from. 
 
 A tubular boiler ought to pre- 
 serve, as' much as possible, the tu- 
 bular form in all its parts ; or, at 
 least, the larger portions ought to 
 be cylindrical, and not of too great 
 diameter, or should be so strongly 
 made that the tubes should form 
 the weakest part of the whole 
 
 505 
 
 boiler. Thetubes themselves should 
 be of such diameter, and be con- 
 structed of such metal, that in case 
 of their actual bursting, no dan- 
 gerous explosion may ensue. This, 
 however, is only possible when 
 their thickness is so small, and 
 the metal of such a kind, that 
 bursting takes place by a compara- 
 tively small internal pressure, and 
 is followed by only a ripping open 
 of the tube, and not a scattering 
 about of massive fragments. Under 
 all circumstances, however, the 
 tubes must be the sole generating 
 vessels : they alone must receive 
 the action of the fire, and be ex- 
 posed to its destructive influence. 
 All other and larger vessels, or 
 parts connected with the tubes, 
 should be most carefully protected 
 from not only this but all other 
 dangerous influences, in order that 
 they may remain in their original 
 proved condition of strength. 
 
 Only such a tubular boiler as 
 fulfils all these conditions can be 
 called a safe one. In its use there 
 is no further danger from high- 
 pressure steam, and near it its 
 owner may repose undisturbed by 
 a care for the safety of life or pro- 
 perty. 
 
 The requisites in the use of the 
 tubes are the following: They 
 must be placed in such a position 
 with regard to the furnace, that the 
 flame may act upon them in the 
 most favourable manner, and that 
 the heat may be absorbed as com- 
 pletely as possible. They must 
 have such a proportion between 
 their length and diameter, that 
 neither the ebullition in them may 
 become too violent, and the water 
 be thereby ejected from them, nor 
 that they become warped or made 
 crooked by the heat. They must 
 properly convey away all the gene- 
 rated steam, and be regularly sup- 
 plied with water. They must be 
 connected with the main part of 
 the boiler in such a manner, that 
 in case of a rupture of one of them, 
 
TUB 
 
 TUBULAR BRIDGES. 
 
 TUB 
 
 the whole content of water and 
 steam cannot suddenly and dan- 
 gerously discharge itself. They 
 must lie so deep under the general 
 water-level of the boiler (in the 
 receivers or separators), that some 
 considerahle sinking of the water 
 may be allowed to take place with- 
 out leaving any of them empty ; 
 and in case the latter effect should 
 occur, such tubes must first be 
 emptied as are least exposed to the 
 heat of the furnace. Lastly, they 
 must be connected with each other 
 in such manner that po destructive 
 expansion may be allowed to take 
 place, and that all may be easily 
 and conveniently cleansed of the 
 earthy matters deposited in them. 
 
 The larger portions of the boiler, 
 or receiving vessels, may themselves 
 consist of tubes of a larger diame- 
 ter, or may form flat chambers, 
 constructed of a strength to with- 
 stand a very high pressure (say 
 400 to 500 Ibs. per square inch): 
 this involves no difficulty. The 
 diameter of the receivers should 
 not, where it can be avoided, ex- 
 ceed 16 inches, and they should be 
 constructed of plate-iron of at least 
 of an inch thick, securely and 
 exactly riveted together into a cy- 
 lindrical form. "When it is neces- 
 sary that they should be capacious, 
 their length should be increased, 
 and not their diameter beyond that 
 specified, or their number should 
 be greater. Their covering lids 
 may be flat and of cast-iron, but 
 of considerable thickness (1 to 2 
 inches), and these must be con- 
 nected to the cylinders securely, 
 and in such a way that they may 
 be easily taken off when cleaning 
 is required. They must, under all 
 circumstances, be entirely removed 
 from all strong action of the fire, 
 and must at most be exposed only 
 to such currents as have discharged 
 the greatest portion of their heat 
 against the generating tubes. In 
 order to preserve them from rust, 
 their internal and external surfaces 
 
 506 
 
 may be covered with several coats 
 of oil-varnish, and the coating re- 
 newed, at least on the inside, every 
 year. 
 
 Since these receivers or larger 
 parts of the boiler usually serve 
 as separators, and as means of con- 
 nection between the generating 
 tubes, they must be perfectly 
 adapted to fulfil these purposes. 
 As separators, they must efficiently 
 separate the steam from the water, 
 so that none of the latter may pe- 
 netrate into the working parts of 
 the engine ; and to this end the 
 water surface in them must be of 
 sufficient extent. In order that the 
 water may not rise to a dangerous 
 height in them by violent ebulli- 
 tion in their tubes, their \\aicr 
 space must bear a certain propor- 
 tion to that of the tubes and the 
 other parts of the boiler. The 
 steam-room in them must also be 
 proportioned to the content of the 
 engine cylinder ; so that the pres- 
 sure may not be too much lessened 
 by the discharge into the engine, 
 and a foaming of the water thereby 
 be caused. Mr. Fairbairn is the 
 great authority for tubular boilers. 
 Tubular Bridges are those in which 
 the requisite strength and rigidity 
 are obtained by disposing the mate- 
 rials in the form of a hori/.ontal 
 tube, through which the passage is 
 formed for the traffic. They are 
 to be distinguished from trussed 
 bridges, which, when constructed 
 of timber and covered over, as in 
 several of the American bridges, 
 resemble a tube, or two or more 
 parallel tubes, being formed en- 
 tirely without trussing, and there- 
 fore admitting of construction with 
 iron only. Tubular bridges are to 
 be regarded as an original and 
 highly important invention, admi- 
 rably adapted for spanning wide 
 spaces, and affording all required 
 strength with a positive minimum 
 of depth. In all arched bridges 
 some portion of the space below, 
 or head room for navigation, is sa- 
 
'UB 
 
 TUBULAR BRIDGES. 
 
 TUB 
 
 crificed by the depending haunches; 
 or, on the other hand, if the road- 
 way is made np to correspond with 
 the chord of the arch, the crown is 
 necessarily elevated to a consider- 
 able height, and additional weight 
 involved in sustaining and preserv- 
 ing the position of the higher parts 
 of the structure. Hence flatness, 
 or the reduction of the total depth 
 has always been a desideratum in 
 the designing of bridges, and scien- 
 tific skill and boldness have achieved 
 several examples in which this pro- 
 perty is attained in a much greater 
 degree than it was once thought 
 safe and prudent to attempt. The 
 wrought-iron tubular bridge, how- 
 ever, is safely constructed with a 
 total depth of T l T th of its span, and 
 with sufficient strength and rigidity 
 to sustain great loads, such as rail- 
 way trains, without sensible vibra- 
 tion or deflection. For bridges of 
 small span, the tubular principle 
 may be adopted in the construction 
 of malleable-iron girders, each of 
 which is itself a rectangular tube 
 of small section, the roadway being 
 thus supported upon two or more 
 of these tubular girders arranged 
 in parallel positions, and at some 
 distance apart. In these bridges 
 a level roadway is formed with a 
 small depth, but the roadway and 
 traffic occupy an additional depth ; 
 whereas in the tubular bridge, as 
 constructed for large spans, the 
 depth of the tube itself comprises 
 the entire depth of the structure, 
 and it may therefore be considered 
 as a vast hollow girder, through 
 which the roadway is formed. Mr. 
 Robert Stephenson appears to have 
 first suggested the idea of form- 
 ing tubular bridges ; and that over 
 the Conway, erected on the line of 
 the Chester and Holyhead Railway, 
 was completed and opened in 1849. 
 This bridge consists of two tubes, 
 placed parallel to each other over 
 a clear span of 400 feet. Each 
 tube, with its castings, etc., weighs 
 about 1300 tons, and is constructed 
 
 507 
 
 of plate-iron riveted upon malle- 
 able-iron ribs, the section of the 
 tube being a rectangle about 30 feet 
 in height and 15 feet wide. The 
 sides, top, and bottom of the tubes 
 consist of long narrow plates of 
 malleable iron, varying in length 
 up to 12 feet, and in width from 
 1 foot 9 inches to 2 feet 4 inches : 
 they vary in thickness from f to 
 f inch. The internal ribs are of 
 T-iron, 3 inches deep, and placed 
 at intervals of 2 feet. A depth of 
 about 1 foot 9 inches across the 
 tube is occupied at top and bottom 
 with narrow cells formed with 
 plate-iron and L-iron corner pieces, 
 all firmly riveted together. These 
 cells are for the purpose of giving 
 the requisite stiffness to these parts 
 of the tube, and are closer together 
 at the top than at the bottom of 
 the tube, as the tendency of a load 
 is to compress the upper part and 
 distend the lower part of the struc- 
 ture, and wrought-iron is, it ap- 
 pears, much better able to resist 
 extension than compression. In 
 his report to the Directors of the 
 Chester and Holyhead Railway, 
 their engineer, Mr. Stephenson, 
 thus referred to some of the re- 
 sults of the experiments which 
 were made in order to determine 
 the form and proportions for his 
 proposed tubular bridge over the 
 Menai Straits. " The first series 
 of experiments was made with plain 
 circular tubes; the second with 
 elliptical ; and the third with rect- 
 angular. In the whole of these 
 this remarkable and unexpected 
 fact was brought to light, viz. that 
 in such tubes the power of wrought 
 iron to resist compression was much 
 less than its power to resist ten- 
 sion, being exactly the reverse of 
 that which holds with cast-iron : 
 for example, in cast-iron beams for 
 sustaining weights, the proper form 
 is to dispose of the greater portion 
 of the material at the bottom side 
 of the beam ; whereas with wrought 
 iron, these experiments demon- 
 
TUB 
 
 TUDOR BADGES. 
 
 TUD 
 
 strate beyond any doubt that the 
 greater portion of the material 
 should be distributed on the upper 
 side of the beam. We have arrived, 
 therefore, at a fact having a most 
 important bearing upon the con- 
 struction of the tube; viz. that 
 rigidity and strength are best ob- 
 tained by throwing the greatest 
 thickness of material into the upper 
 side. Another instructive lesson 
 which the experiments ha\e dis- 
 closed is, that the rectangular tube 
 is by far the strongest, and that 
 the circular and elliptical should 
 be discarded altogether." 
 
 Another tubular bridge, similar 
 to that at Conway, and the Britan- 
 nia, near Bangor, exceeding these 
 bridges in extent, has just been 
 completed in Canada, over the St. j 
 Lawrence. 
 
 These grand bridges differ little 
 less in the mode of constructing 
 and erecting them than in their 
 design, from ordinary bridges of 
 stone, timber, or iron. Thus the 
 larger tubes over the water-way 
 are put together adjacent to their 
 final resting-place, and when com- 
 plete as tubes, they are launched 
 upon pontoons, floated to the piers, 
 and raised to their places complete 
 and entire by hydraulic presses 
 operating at each end. For this 
 purpose of raising, strong tempo- 
 rary frames of cast-iron are fitted 
 to the ends of the tube, and made 
 fast to solid bar-link chains, the 
 upper ends of which are forced up- 
 wards bv successive lifts of the 
 hydraulifr press, each lift being 6 
 feet, and the ends of the tube being 
 packed up as the raising proceeds, j 
 One end of each tube is perma- 
 nently laid upon cast-iron rollers, 
 to admit of the changes of length 
 produced by variations of tempera- 
 ture. For the purposes of the rail- 
 way, transverse plates of iron are 
 fixed edgewise on the bottom of 
 the tube, and support longitudinal 
 balks of timber, upon which the 
 rails are laid. The height of the 
 
 508 
 
 Conway Bridge is 18 feet at the 
 bottom of the tubes above high 
 water; that over the Menai Straits, 
 called the ' Britannia' Bridge, 102 
 feet above the same level. 
 Tudor Badges. The badges of the 
 house of Tudor were either assumed 
 or derived from descent or alliance : 
 the red rose was the peculiar dis- 
 tinction of the house of Lancaster, 
 and was borne by Henry VII. as 
 Earl of Richmond. The portcullis 
 was the badge of the Beaufort 
 branch of the same family, assumed 
 by the descendants of John of 
 Ghent, born in the castle of Beau- 
 fort; and agreeably to heraldic 
 simplicity, a part of the castle, its 
 most prominent feature, was depict- 
 ed for the w hole. The fleur-de-lis 
 was also a badge of the house of 
 Lancaster, and was introduced, to- 
 gether with the rose, in the border 
 of Henry's arms, as Earl of Rich- 
 mond. Descended from Cadwalla- 
 der, the last of the British kings. 
 and deriving from him the name of 
 Tudor, he assumed the badge of 
 the red dragon, Cadwallader's en- 
 sign. After the battle of Bosworth 
 Field, Henry took as a badge the 
 hawthorn bush, crowned, in allu- 
 sion to the circumstance of the 
 crown being found in a hedge, 
 whence it was taken and placed oti 
 his head. The red rose, or rose of 
 Lancaster, he placed on the sun- 
 beams, as the white rose had been 
 by the head of the house of York. 
 This monarch assumed the Tudor 
 rose, or the red rose charged with 
 the white, as emblematical of his 
 united claims to the throne by 
 his marriage with Elizabeth, the 
 daughter and sole heir of Edward 
 IV. Upon the marriage of Prince 
 Arthur with Catherine of Arragon, 
 he adopted, in compliment to her, 
 the badges of her house. The castle 
 was an ancient badge of the house 
 of Granada. The sheaf of arrows 
 was assumed by the house of Ar- 
 ragon on the conquest of Gra- 
 nada, which had been achieved by 
 
'UD 
 
 TUNNEL. 
 
 TUN 
 
 the superiority of the Arragonese 
 archers. The rose dimidiated with 
 the pomegranate was adopted as 
 heing symbolical of the junction of 
 England and Spain. The phoenix 
 in flames was assumed by Edward 
 VI., in allusion to the particular 
 nature of his birth, and was grant- 
 ed by him to the family of Sey- 
 mour. A white falcon, crowned, 
 and holding a sceptre, was assumed 
 by Queen Anne Boleyn as her pe- 
 culiar badge, and was continued by 
 her daughter, Queen Elizabeth. 
 The harp, an ancient badge of Ire- 
 land, was used by Queen Elizabeth. 
 The rose environed by the garter, 
 with its motto, was a badge of 
 several branches of the Tudor 
 family. All these badges were re- 
 presented crowned, when borne by 
 the monarch, and were occasionally 
 placed between the royal sup- 
 porters. 
 
 Tudor Style of Architecture, a con- 
 tinuation of the Perpendicular 
 Style, merging into a peculiarity in 
 the time of Henry VIII., when it 
 was much applied to domestic pur- 
 poses and to edifices for collegiate 
 halls, and several foundations for 
 educational and charitable uses, thus 
 appropriating the proceeds of mo- 
 nastic revenues. The mansions of 
 the Tudor period usually consisted 
 of an inner and base court, between 
 which stood the gate-house. The 
 principal apartments were the great 
 chamber, or room of assembly, the 
 hall, the chapel, the gallery for 
 amusements, on an upper story, 
 running the whole length of the 
 principal side of the quadrangle, 
 and the summer and winter par- 
 lours. Of quadrangular houses, 
 the seats of the Bishops of Car- 
 lisle, Cowdry, Halnaker, etc., may 
 be taken as fair examples. In 
 a work entitled ' Studies of Ancient 
 Houses' (a book of a convenient 
 size and price) are some fine ex- 
 amples in this style, but of a 
 smaller kind. Very many splendid 
 examples of larger dimensions of 
 
 halls, mansions, etc., still exist 
 scattered over the country. 
 
 Tufa, a calcareous earth, composed 
 of broken and concreted shells, or 
 the deposit from water impregnated 
 with lime. 
 
 Tugs, in mining, hoops of iron fas- 
 tened to the covers to which the 
 tackles are affixed. 
 
 Tugs, steam, small steam-vessels em- 
 ployed in towing other craft. 
 
 Tulip wood, from Brazil, is frequently 
 unsound in the centre, very hand- 
 some, but soon fades ; it is used 
 in turnery and Tunbridge ware. 
 
 Tumbling -home, in nautical language 
 the falling into midships of the 
 top-side above the main breadth, 
 to bring the upper deck guns 
 nearer the centre of the ship. 
 
 Tumbril, a machine for the punish- 
 ment of scolding women, consisting 
 of a chair attached to a long pole ; 
 the offender was placed in the 
 chair, swung over a pond, and im- 
 mersed as often as necessary. 
 
 Tummak, in mining, a great quantity 
 or heap. 
 
 Tumulus, a heap, or mound of earth, 
 sometimes called a barrow, used 
 for the burial of the dead previous 
 to the Roman invasion of Britain. 
 
 Tunnel, a large and subterraneous 
 arch, driven through an elevation 
 or hill, or under a river, for the 
 passage of boats, carriages, etc. 
 
 Among the costly and laborious 
 works of a railway, its tunnels oc- 
 cupy the first place. Like mining 
 and all other subterranean ope- 
 rations, the construction of a tun- 
 nel can be but little aided by me- 
 chanical appliances ; it chiefly re- 
 quires hard manual labour, exer- 
 cised under circumstances which 
 do not admit of that thorough 
 superintendence which promotes 
 economy, and, moreover, liable to 
 unforeseen interruptions, of sur- 
 mounting which neither the man- 
 ner nor the expense can be prede- 
 termined. Thus the Kilsby tunnel, 
 on the London and Birmingham 
 Railway, was estimated to cost 
 
 509 
 
TUN 
 
 Tl'NXEL. 
 
 TUN 
 
 about 40 per yard lineal ; \vhefeas 
 its actual cost' was 130 for the 
 same length, owing to its inter- 
 secting a quicksand, which the 
 trial borings had escaped. Thus a 
 vast expense was necessarily in- 
 curred in setting up and working 
 pumping machinery in order to 
 dry the sand. The pumps brought 
 up nearly 2000 gallons per minute, 
 and were working during a period 
 of nine months. The quicksand 
 extended over a length of about 
 450 yards of the tunnel. The Box 
 tunnel, on the Great Western Rail- 
 way, excavated through oolite rock, 
 and being lined with masonry only 
 through a portion of its length, 
 cost upwards of 100 per lineal 
 yard. The Bletchingley tunnel, on 
 the South-eastern Railway, cost 
 72 per lineal yard; and the Salt- 
 wood tunnel, on the same line of 
 railway, cost 118 per lineal yard. 
 This greater cost in the latter work 
 was occasioned by the great body 
 of water in the lower green-sand 
 which the tunnel intersects. 
 
 The method of proceeding with 
 tunnelling depends mainly upon 
 the kind of material to be ex- 
 cavated. This having been gene-,, 
 rally ascertained by borings and' 
 trial shafts, the work is commenced 
 by sinking the working shafts, 
 which must be sufficiently capa- 
 cious to admit readily of lowering 
 men and materials, raising the ma- 
 terial excavated, fixing pumps, and 
 also for starting the heading of the 
 intended tunnel when the required 
 depth is reached. Besides the trial 
 and working shafts, air-shafts are 
 sunk for the purpose of effecting 
 ventilation in the works below. 
 
 The working shafts are made 
 cylindrical, and from 8 to 10 feet 
 internal diameter : 9 feet is a fa- 
 vourite dimension. They are of 
 brickwork, usually 9 inches thick, 
 and carried up 8 or 10 feet above 
 the surface of the ground, finished 
 with stone coping. These, and all 
 other shafts, rest upon curbs of 
 
 cast-iron, fitted into the crown of 
 the tunnel, and forming a level 
 base for the shaft. The air-shafts 
 are of similar thickness and form, 
 but usually about 3 feet internal 
 diameter. They should not be 
 allowed to be sunk near to the 
 working shaft, or at a less distance 
 than 50 yards from it. All the 
 shafts are of course sunk on the 
 centre line of the intended tunnel. 
 In the Bletchingley tunnel, the 
 trial-shafts, 6 feet diameter in the 
 clear, 9 inches thick, and 35 i yards 
 deep, cost 6 per yard down 
 through the Weald clay. A similar 
 shaft in the Saltwood tunnel, 25 
 yards deep, cost 4. 15*. per yard 
 down, in the lower green-sand. 
 Horse gins are usually employed 
 in raising and lowering the ma- 
 terials, etc., and also in drawing 
 the water up the shafts, unless 
 large pumps are used and worked 
 by steam-power. The engineer cal- 
 culated the expense of horse labour 
 thus exercised at 2|rf. per ton, 
 lifted 100 feet high, and including 
 the boy to drive the horse. 
 
 The number of working shafts 
 will depend chiefly upon the rate 
 of speed with which the work is 
 required to be accomplished. With 
 plenty of men, horses, materials, 
 and plant, the work is much facili- 
 tated by sinking extra shafts, which 
 will usually well repay their cost. 
 The Watford tunnel, 75 chains in 
 length, on. the London and Bir- 
 mingham Railway, was specified to 
 be worked with six shafts, not less 
 than 8 feet diameter within the 
 brickwork, and 9 inches thick; 
 the brickwork moulded to fit the 
 circumference of the shaft, and 
 laid in two half-brick rings ; an 
 . air-shaft at a distance of 50 yards 
 on each side of each working shaft, 
 and not less than 3 feet 6 inches 
 diameter inside ; the arch and side- 
 walls of the tunnel, usually two 
 bricks thick, and the invert, one 
 and a half brick, except in places 
 where the stratum passed* through 
 
 510 
 
TUNNEL. 
 
 TUN 
 
 seemed. to require an increased, or 
 admit a diminished thickness. The 
 form of the top of the tunnel is 
 nearly semicircular, supported by 
 curved side-walls standing on stone 
 footings or skew-backs, which rest 
 on the invert forming the base of 
 the tunnel. The ends of the tunnel 
 are formed with wing-walls. The 
 brickwork at the ends of the tunnel 
 is bound by wrought-iron rods 100 
 feet long, secured at each end in a 
 cast-iron rim or plate built into the 
 brickwork. 
 
 The Northchurch tunnel, which 
 is 16 chains in length, on the same 
 line of railway, was worked with 
 two shafts, each 9 feet diameter. 
 In the construction of this tunnel, 
 [ a heading was driven, 4 feet wide 
 i and 5 feet high, throughout the 
 entire length of the tunnel, and 
 between two shafts sunk for this 
 I purpose, one near each end of it. 
 It was specified that this heading 
 should be driven through before 
 any part of the tunnel was com- 
 menced, and supported and kept 
 open during the execution of the 
 entire work by sufficient timbering. 
 In commencing the works of the 
 Saltwood tunnel, already referred 
 to, great difficulty was encoun- 
 tered from the great quantity of 
 water in the lower green-sand 
 which the tunnel intersects. The 
 course adopted was to make a 
 heading or adit quite through the 
 hill on a level with the bottom of 
 the tunnel, in which the water was 
 collected and drained off. The 
 size of this, and of the Bletch- 
 ingley tunnel, is 24 feet wide at 
 the broadest part, 30 feet including 
 the side-walls ; 55 feet high in the 
 clear, 30 feet including the invert 
 and top arch, or 21 feet clear above 
 the level of rails. The brickwork in 
 the top arch and walls is from two 
 and a half to four bricks in thick- 
 ness ; the invert three bricks thick. 
 When water occurs in the sink- 
 ing of the shafts or the building of 
 a tunnel, the back of the brick- 
 
 511 
 
 work should be well lined with 
 puddle, and Roman or metallic 
 cement substituted for mortar. 
 The whole of the Kilsby tunnel, on 
 the London and Birmingham Rail- 
 way, was built in either Roman or 
 metallic cement, and the thickness 
 of the brickwork is chiefly 27 
 inches. This tunnel is about 2423 
 yards long, and its length is divi- 
 ded by two ventilating shafts, cy- 
 lindrical, and 60 feet in diameter. 
 These shafts are 3 feet thick in 
 brickwork, laid in Roman cement 
 throughout. They intersect the 
 line of the tunnel, and thus form 
 curved recesses by that portion of 
 their circumference which extends 
 beyond the width of J^ie tunnel on 
 either side. These shafts were 
 built from the top downwards, by 
 excavating for small portions at a 
 time, from 6 to 12 feet in length 
 and 10 feet deep. 
 
 The Box tunnel, on the Great 
 Western Railway, intersects oolite 
 rock, forest marble, and lias marl, 
 with fuller's-earth. Eleven prin- 
 cipal shafts, generally 25 feet in 
 diameter, and four immediate shafts 
 12 feet 6 inches, were sunk for the 
 purpose of carrying on the works 
 of this tunnel, the entire length of 
 which is 3123 yards, or a little 
 more than If mile. The section 
 of the tunnel was designed to be 27 
 feet 6 in. wide at the springing of 
 the invert, and 30 feet at a height 
 of 7 feet 3 inches above this ; clear 
 height above the rails 25 feet. As a 
 great portion of the tunnel was con- 
 structed by mere excavation, and 
 without masonry, these dimensions 
 were in some cases departed from, 
 in order to clear away loose por- 
 tions of the stone and secure solid 
 surfaces. Where brickwork is 
 used, the sides are seven half-brick 
 rings in thickness, the arch six, and 
 the invert four. During the con- 
 struction, the constant flow of wa- 
 ter into the works, from the nume- 
 rous fissures in the rock, compelled 
 pumping on a most expensive scale 
 
TUN 
 
 TUNNEL. 
 
 TUN 
 
 to be adopted. From Novefhber, 
 1837, to July, 1838, the works 
 were suspended, the water having 
 gained so completely over the steam 
 pump then employed, that the por- 
 tion of the tunnel then completed 
 was filled with water, as also a 
 height of 56 feet in the shafts. A 
 second purnp, worked by a steam- 
 engine of 50-horse power, was ap- 
 plied, and enabled the works to be 
 resumed. 
 
 When the working shaft saresunk 
 sufficiently deep, a narrow heading 
 is excavated, from 6 to 12 feet in 
 length, 3 or 4 feet wide, and high 
 enough for a man to work in. The 
 top of this heading should be so 
 much above the intended soffit of 
 the tunnfl-arch as to admit the 
 thickness of the brickwork, besides 
 the bars of timber and boarding by 
 which the roof- of the heading is 
 supported,and several inches should 
 be allowed for the settlement of the 
 timber, which always occurs as 
 the excavation is proceeded with, 
 and before the brickwork can be 
 got in. 
 
 This allowance is of the utmost 
 importance, as without it the brick- 
 work will, when the settlement 
 occurs, be forced down, and can 
 only be raised to its proper level 
 by removing the superincumbent 
 earth piecemeal, and at great cost. 
 The bars and polling and packing 
 boards, are introduced in the most 
 convenient manner, according to 
 the nature of soil excavated, and 
 the degree in which it requires 
 support, or may be safely left un- 
 supported. 
 
 The heading isextendedon either 
 side by first cutting narrow gaps 
 horizontally, or rather dipping 
 downwards in directions following 
 the intended form of the tunnel- 
 arch. Into these gaps, crown bars 
 are laid lengthwise, and supported 
 upon props ; and poling boards are 
 put in between them, to retain the 
 earth at the sides of the excavation, 
 when extended. When the head- 
 
 512 
 
 ing has thus been widened by ex- 
 cavating right and left, and a suffi- 
 cient length cleared, the centerings 
 are fixed, and the brickwork is 
 commenced. As this proc eds, the 
 earth is carefully rammed behind 
 it, and all vacancies filled up, to 
 prevent any subsequent settlement 
 of the surrounding earth upon it. 
 The crown bars which are in- 
 serted in the heading, and always 
 during the excavations, are not 
 invariably removed. If they can be 
 drawn forward as the heading ad- 
 vances, without disturbing the adja- 
 cent ground, and the spaces filled 
 up with broken stone, or othei 
 suitable material, no objection can 
 arise ; but otherwise they should 
 be allowed to remain, and be built 
 in. The whole of the operations 
 require carefully regulating, so that 
 none of them shall advance toe 
 rapidly for those which follow 
 Contractors are therefore usuallj 
 restricted to carry the excavatior 
 not more than 6 or 8 feet in ad' 
 vance of the brickwork, or less, ii 
 so directed by the engineer, shoulc 
 any change occur in the strata 
 which he thinks may require sucl 
 precaution. When the faces o; 
 two contiguous excavations ap. 
 proach within about fifty yardi 
 of each other, a heading should b< 
 driven quite through the inter 
 vening ground, and the working! 
 'joined before the whole excavatioi 
 and brickwork are proceeded with 
 Experience has proved that th< 
 quality of the bricks used in tun 
 nel-work is of the utmost import 
 ance. If these contain lime, 01 
 which the weather operates in 
 juriously, the face of the work sooi 
 decays, and requires extensive re 
 pair or restoration. This was tlu 
 case with the Beech wood tunne 
 on the London and Binninghan 
 Railway, which in less than thre< 
 years was considered to be in ai 
 unsafe condition, owing to thi 
 cause. The remedy adopted wa 
 of the most complete character 
 
'UR 
 
 TURBINE WHEEL. 
 
 TUR 
 
 it consisted in an entirely new 
 lining of brickwork, 9 inches 
 thick. This tunnel is about 302 
 yards long, and passes through 
 strata consisting of alternate layers 
 of rock and marl, abounding with 
 springs of water. By judicious ar- 
 rangement, the lining was com- 
 pleted in forty days. The traffic 
 being diverted to one of the two 
 lines of rails which are laid in the 
 tunnel, and a hoarding erected 
 along the centre, the casing was 
 carried up on one side to the 
 height of 4 feet 6 inches above the 
 springing. At this point a course 
 of York paving, 4f inches thick, 
 was bonded into the original work, 
 and the new work was securely 
 attached beneath it with wedges 
 of iron ; half-brick toothings were 
 also inserted in chases cut 2 feet 
 3 inches apart in the original work. 
 The traffic was then turned into 
 the line on the side thus cased, and 
 the other wall was similarly treated. 
 Bearers were then fixed 6 feet 
 apart over-head, and a close floor- 
 ing laid upon them. Upon each 
 bearer a pair of ribs was raised, 
 and keyed stays and laggings were 
 fixed, and the brickwork, in En- 
 glish bond, brought up on each 
 side simultaneously, leaving a cen- 
 tral space 2 feet 3 inches wide at 
 the crown. A movable centre of 
 this length was used to close in 
 this space with two half-brick rings. 
 Vertical chases, 4^ inches square, 
 besides those cut for the toothings, 
 were made in the face of the old 
 walls previous to lining. These 
 formed permanent drains, termi- 
 nating in the culvert beneath the 
 centre of the tunnel. For the ex- 
 traordinary works now in progress 
 tunnelling through the Alps see 
 ' Engineer's Pocket Book 'for 1859. 
 n arline Water-wheel. The hori- 
 zontal water - wheel so called, as 
 used in France and Germany, was 
 invented by M. Fourneyron : the 
 water enters at the centre, and, 
 diverging from it in every di- 
 
 rection, it then enters all the 
 buckets simultaneously, and passes 
 off at the external circumference 
 of the wheel. The pressure with 
 which the water acts on the 
 buckets of the revolving wheel is 
 in proportion to the vertical column 
 of water, or heights of the fall, 
 and it is conducted into these 
 buckets by fixed curved girders se- 
 cured upon a platform within the 
 circle of the revolving part of the 
 machine. The efflux of the water 
 is regulated by a hollow cylindrical 
 sluice, to which stops are fixed, 
 which act together between the 
 guides, and are raised or lowered 
 by screws that communicate with 
 a governor, so that the opening of 
 the sluice and stops may be en- 
 larged or reduced in proportion as 
 the velocity of the wheel requires 
 to be accelerated or retarded. Tur- 
 bines may be divided into high- 
 pressure and low-pressure engines. 
 High - pressure turbines are par- 
 ticularly available in situations such 
 as often occur in hilly districts 
 where high falls of water may be 
 conimanded, and the character of 
 the site affords facilities for con- 
 structing reservoirs, so that a con- 
 stant supply may be ensured. In 
 these cases the height of the co- 
 lumn of water will compensate for 
 the smallness of its volume, and 
 the high-pressure turbine will be 
 found applicable with great ad- 
 vantage to the grinding of corn, 
 crushing ores, working threshing- 
 machines, or actuating other ma- 
 chinery. The low-pressure tur- 
 bines produce great effect with a 
 head of only nine inches, and are 
 suitable for situations in which a 
 large bulk of water flows with 
 little fall. The results of an in- 
 vestigation by MM. Arago, Prony, 
 Gambey, and Savary, who were 
 appointed by the French Academic 
 des Sciences to report upon tur- 
 bines, are given in a treatise by 
 M. Morin on the subject, and are 
 as follows : 
 
TUR 
 
 TURBINE WHEEL. 
 
 TU 
 
 1. That these wheels are appli- 
 cable equally to great and to small 
 falls of water. 2. That they trans- 
 mit a useful effect, equal to from 
 70 to 78 per cent, of the absolute 
 total moving force. 3. That they 
 may work at very different velo- 
 cities, above or below that cor- 
 responding to the maximum effect, 
 without the useful effect varying 
 materially from that maximum. 
 
 4. That they may work from one 
 to two yards deep under water, 
 without the proportion which the 
 useful effect bears to the total 
 force being sensibly diminished. 
 
 5. In consequence of the last pre- 
 ceding property, they utilize at all 
 times the greatest possible propor- 
 tion of power, as they may be 
 placed below the lowest levels to 
 which the water surface sinks. 
 
 6. That they may receive very va- 
 riable quantities of water without 
 the relation of the useful effect to 
 the force expended being mate- 
 rially lessened. 
 
 The practical value of these ma- 
 chines is most obvious when they 
 are applied to small falls of water. 
 Smeaton's experiments proved that 
 with a high fall in which an over- 
 shot water-wheel can be intro- 
 duced, 80 per cent, of the original 
 moving power may be realized. 
 And there is little doubt, accord- 
 ing to Riihlman, whose treatise on 
 turbines has been so well trans- 
 lated and edited by Sir Robert 
 Kane, that where an overshot 
 wheel, or a wheel with tolerably 
 high breasts and overfall sluices, 
 can be erected, they are to be pre- 
 ferred to the turbine, except there 
 is much back - water to contend 
 against, when the turbine may be 
 sunk to a considerable depth in 
 the back-water without any mate- 
 rial loss of its power. Even in 
 cases which admit the working of 
 overshot wheels, the peculiar ap- 
 plicability of the turbine, which 
 affords a direct horizontal motion 
 to the working of corn-mills, should 
 
 command full consideration befoi 
 it is relinquished in favour of th 
 overshot wheel. In every case ( 
 fall, either higher than that suit 
 able for an overshot wheel, c 
 lower than that required for such 
 breast-wheel as just described, th 
 turbine decidedly deserves the pr< 
 ference. Smeaton proved that ui 
 dershot wheels realized only 30 pi 
 cent, of the original force. 
 
 In falls of great height, the vi 
 locity of the machine is so rapi 
 that it may be applied to spinnin 
 machinery without mill-work, c 
 with very little, to produce th 
 required speed. The turbine i 
 its present form is of compar; 
 tively modern date ; the ex per 
 ments of M. Fourneyron, \\liic 
 resulted in its invention, havin 
 been commenced in 1823, and tl; 
 first machine was erected in ]*2. 
 In tracing this form of water-mote 
 to its elements, however, the coi 
 trivance which is known as D 
 Barker's mill must necessarily 1 
 noticed. This machine, which is < 
 very old date, consists of an u| 
 right pipe or tube, which revolve 
 on a vertical axis, and is forme 
 with an open funnel-shaped to| 
 and closed at the bottom, froi 
 which project two horizontal ho 
 low arms or pipes. These arn 
 are closed at their outer ends, In 
 have each a round hole near tii 
 extremity, and so placed that tli 
 two holes are opposite to eac 
 other. The upright pipe is kej 
 filled with water, which flows int 
 the funnel-shaped top. The issi 
 ing of the water from the holes o 
 opposite sides of the horizont; 
 arms causes the machine to n 
 volve rapidly on its axis, with 
 velocity nearly equal to that of th 
 effluent water, the force being i 
 proportion to the hydrostatic pre; 
 sure which is exerted by the vei 
 tical column, and to the area ( 
 the apertures ; there being no soli 
 surface at the hole on which th 
 lateral pressure can exert itse 
 
 514 
 
IUR 
 
 TURBINE WHEEL. 
 
 TUR 
 
 while it is acting with its full 
 force on the opposite side of the 
 arm. This unbalanced pressure is, 
 according to Dr. Robison, equal to 
 the weights of a column having 
 the orifice for its base, and twice 
 the depth under the surface of the 
 water in the trunk for its height. 
 If the orifice were closed, the 
 pressure upon it would equal the 
 weights of a column reaching to 
 the surface ; but when open, the 
 water issues with a velocity nearly 
 equal to that acquired by falling 
 from the surface, and the quantity 
 of motion which is produced is 
 that of a column of twice this 
 length moving with this velocity. 
 The revolution of the machine 
 causes the water, which having de- 
 scended the vertical pipe moves 
 along the arms, to partake of the 
 circular motion, thus producing a 
 centrifugal force that is exerted 
 against the ends of the arms of 
 the machine. According to the 
 laws of motion, this force increases 
 in proportion to the square of the 
 distance from the centre at which 
 it is developed. Thus the velocity 
 of the efflux is increased, and also 
 the velocity of revolution. But as 
 the circular motion has to be im- 
 parted to every particle of water 
 as it enters the horizontal arm, 
 which is done at the expense of 
 the motion already acquired by 
 the arm, there is a limit to the 
 velocity even of an unloaded ma- 
 chine. Barker's mill has been 
 treated of by Desaguliers, Euler, 
 John Bernouilli, and M. Mathon de 
 la Cour, the latter of whom pro- 
 posed, in 1775, to bring down a 
 large pipe from an elevated reser- 
 voir, to bend the lower part of it 
 upwards and attach to it a short 
 pipe with two arms, like Barker's 
 mill reversed, and revolving in like 
 manner upon a vertical spindle ; 
 the joint of the two pipes being 
 contrived so as to admit of a free 
 circular motion without much loss 
 of water. By this arrangement a 
 
 515 
 
 fall of an extended depth may be 
 made available. An improved form 
 of Barker's mill was patented sub- 
 sequently by Mr. Whitelaw, in 
 which the modifications suggested 
 by M. M. de la Cour were partly 
 included, and a peculiar form given 
 to the horizontal arms, adapted to 
 preserve the centrifugal force from 
 loss or counteraction. 
 
 In this mill the two arms form 
 the letter S, the water being 
 emitted from their extremities in 
 the direction of the circle traced 
 by their revolution, the sectional 
 capacity of the arms increasing as 
 they approach the centre of rota- 
 tion, so as to contain a quantity 
 of water, at each section of the 
 arm, inversely proportional to its 
 velocity at that section. 
 
 With a well-made model of this 
 mill, the patentee obtained an 
 effect equal to 73'6 per cent, of 
 the power employed, and nearly 
 equal results are said to have been 
 realized in actual practice. The 
 following particulars of the height 
 of fall and useful effect produced 
 with turbines, already erected on 
 the Continent, will tend to show 
 their increasing value in proportion 
 to the heights of the acting column 
 of water: 
 
 Heights 
 
 of 
 fall in feet. 
 
 7- 
 
 63 
 
 79 
 126 
 144 
 
 Useful effect 
 per cent, 
 of power 
 employed. 
 
 71- 
 75 
 
 87 
 81 
 80 
 
 In 1837 a turbine water-wheel 
 was erected by M. Fourneyron, 
 an account of which is here 
 quoted from Mr. Joseph Glynn's 
 Report to the British Association 
 for the Advancement of Science in 
 1847. This turbine is ''erected 
 at St. Blasier, or Blaise, in the 
 Black Forest of Baden, for a fall 
 or column of water of 72 feet 
 
TUR 
 
 TURF. 
 
 TUR 
 
 (22 metres). The wheel is made 
 of cast -iron with wrought -iron 
 buckets ; it is about 20 inches in 
 diameter, and weighs about 1 05 Ibs. ; 
 it is said to be equal to 56 horses' 
 power, and to give a useful effect 
 equal to 70 or 75 per cent, of the 
 water-power employed. It drives 
 a spinning-mill belonging to M. 
 d'Eichtal. A second turbine, at 
 the same establishment, is worked 
 by a column of water of 108 
 metres, or 354 feet high, which is 
 brought into the machine by cast- 
 iron pipes of 18 inches diameter of 
 the local measure, or about 16j 
 inches English. The diameter of 
 the water-wheel is 14$, or about 
 13 inches English, and it is said 
 to expend a cubic foot of water 
 per second : probably the expen- 
 diture may be somewhat more than 
 this. The width of the water- 
 wheel across the face is '225, or 
 less than a quarter of an inch. It 
 makes from 2200 to 2300 revolu- 
 tions per minute; and on the end 
 of the spindle, or upright shaft of 
 the turbine, is a bevelled pinion of 
 nineteen teeth, working into two 
 wheels on the right and left, each 
 of which has 300 teeth : these give 
 motion to the machinery of the fac- 
 tory,and drive 8000 water-spindles, 
 roving - frames, carding - engines, 
 cleansers, andotheraccessories. The 
 useful effect is reported to be from 
 80 to 85 per cent, of the theo- 
 retical water-power. The water is 
 filtered at the reservoir before it 
 enters the conduit-pipes ; and it is 
 important to notice this, since the 
 apertures of discharge in the water- 
 wheel are so small as to be easily 
 obstructed or choked." 
 Turbith or Turpith mineral ( Queen's 
 yellow] is subsulphate of mercury, 
 of a beautiful lemon-yellow colour, 
 but so liable to change by the action 
 of light or impure air, that, not- 
 withstanding it has been some- 
 times employed, it cannot be used 
 safely, and hardly deserves atten- 
 tion as a pigment. 
 
 Turf is generally found in bogs, in 
 horizontal layers from 10 to 30 
 feet in thickness ; sometimes in the 
 form of a blackish-brown mud; 
 sometimes it is a dark peaty mass, 
 and often a combination of roots 
 and stalks of plants : frequently 
 the turf layers interchange with 
 layers of sand or clay. Sea-water 
 is better adapted to the formation 
 of turf than rain or spring water. 
 
 Turf is simply dug with >{>;ul ;*, 
 and then dried. If too moi>t, 
 the semi-fluid mass is piled upon 
 a dry spot, and there left until 
 the water leaks off, and until the 
 mass appears dry enough to be 
 formed into square lumps in the 
 form of bricks. In many instances, 
 however, the freshly dug turf is 
 triturated under ' revolving edge- 
 wheels, faced with iron plates per. 
 forated all over their surface ; 
 through the apertures in these 
 plates the turf is pressed till it 
 becomes a kind of pap, which is 
 put into a hydraulic press, and 
 squeezed until it looses the greater 
 part of its moisture: it is then 
 dried and charred in suitable ovens. 
 
 The charcoal made in this way 
 deserves the notice of the artisan. 
 The component parts of turf dif- 
 fer from those of wood. This dif- 
 ference is owing to the fact of its 
 being decomposed woody fibre. 
 The following is an analysis of 
 several specimens : 
 
 One hundred parts of good turf 
 contained, besides ashes, 
 
 Carbon. Hydrogen. Oxygen. 
 I. 57-03 5-63 31-76 
 II. 58-09 6-93 31-37 
 
 III. 57-79 6-11 3077 
 
 The charring of turf is far more 
 easily effected than the charring o! 
 wood, partly on account of it 
 square form, partly on account ol 
 its chemical composition. In pits 
 the charring of turf is not difficult 
 if the same method is pursued as 
 that adopted in the charring o 
 wood ; but channels or draft-hole; 
 
 516 
 
TURNING TOOLS. 
 
 TUR 
 
 must be left in the kiln, because 
 the square pieces pack so closely, 
 that, without this precaution, suffi- 
 cient draught would riot be left to 
 conduct the fire. Turf is generally 
 found in considerable masses in 
 one spot ; therefore the erection 
 of char-ovens is no object of mere 
 speculation, but affords all the ad- 
 vantages of a permanent establish- 
 ment. 
 
 Turpentine, an oleo-resin procured 
 chiefly from trees of the fir-tribe ; 
 spirits of turpentine are obtained 
 from this by distillation, the resi- 
 due being the substance known as 
 resin, or rosin. 
 
 TurnbulVs blue (ferricyanide of iron). 
 Professor Graham's account of this 
 variety of Prussian blue is nearly 
 as follows : It is formed by adding 
 ferricyanide of potassium (red prus- 
 siate of potash) to a protosalt of 
 iron; it results from the substi- 
 tution of three equivalents of iron 
 for three equivalents of potas- 
 sium. The same blue precipitate 
 may be, obtained by adding to a 
 protosalt of iron a mixture of yel- 
 low prussiate of potash, chloride 
 of soda, and hydrochloric acid. 
 The tint of this blue is lighter and 
 more delicate than that of Prus- 
 sian blue. It is occasionally used 
 by the calico-printer, who mixes it 
 with perchloride of tin, and prints 
 the mixture, which is in a great 
 measure soluble, upon Turkey red 
 cloth, raising the blue colour after- 
 wards by passing the cloth through 
 a solution of chloride of lime, con- 
 taining an excess of lime. The 
 chief object of this operation is to 
 discharge the red and produce 
 white patterns, where tartaric acid 
 is printed upon the cloth ; but it 
 has also the effect incidentally of 
 precipitating the blue pigment and 
 peroxide of tin together on the 
 cloth, by neutralizing the chlorine 
 of the perchloride of tin. This 
 blue is believed to resist the action 
 of alkalis longer than ordinary 
 Prussian blue. 
 
 517 
 
 Turner's yellow, Cassel yellow, Patent 
 yellow. This is an oxychloride of 
 lead, which may be prepared by 
 different processes : when litharge 
 or the protoxide of lead is acted 
 upon by a solution of common 
 salt, there are formed, soda, which 
 remains dissolved, and a white com- 
 pound, which is hydrated oxychlo- 
 ride of lead ; and this, when heated, 
 loses water, becomes of a yellow 
 colour, and is the compound re- 
 quired. It is composed nearly of 
 one part of chloride and nine parts 
 of oxide of lead : it may also be 
 obtained by heating chloride and 
 oxide of lead together in the requi- 
 site proportions, or by heating a 
 mixture of one part of hydrochlo- 
 rate of ammonia with ten parts of 
 protoxide of lead. In fusing these 
 compounds it is requisite to be ex- 
 tremely careful to avoid any ad- 
 mixture of carbonaceous or com- 
 bustible matter, as that would 
 reduce a portion of the oxide of 
 lead to its metallic state, and thus 
 injure the colour of the product. 
 
 Turning tools. These are of two 
 classes, viz. hand-tools and tools 
 fixed in the slide-rest. Of the 
 former, the principal are the heel- 
 tool, graver, planisher, gouge, ami 
 chisel ; there are many others which 
 however are but modifications of 
 these, and are required only in 
 particular cases. 
 
 The slide-rest tools are distin- 
 guished by the same names as the 
 hand-tools, but vary from them 
 slightly in the forms of their cut- 
 ting parts, which in the hand-tools 
 are in general rather broader, in 
 order that the part to be cut away 
 may be acted on as long as possible 
 before shifting the tool; for forward 
 motion is in their case continuous 
 only for the short period while the 
 cutting edge can be brought to 
 bear on the material without shift- 
 ing forward the resting point of 
 the tool. The face or front edge 
 of the tool should in every case be 
 nearly perpendicular to the hori- 
 
TUR 
 
 TUYERE. 
 
 TUY 
 
 zontal diameter of the work, tmt 
 a small difference is required for 
 clearance. 
 
 The angle of the cutting edge 
 should be more or less acute, ac- 
 cording to the nature of the mate- 
 rial to be turned ; in general, the 
 softer and more uniform the mate- 
 rial, the more acute should be the 
 angle : for wood, it should be very 
 acute, and for iron and steel less 
 acute. The velocity with which 
 the work is made to revolve must 
 also be adapted to the material, 
 and must be such that the tool may 
 take the greatest effect consistent 
 with the preservation of its cutting 
 edge. 
 
 The hardening and tempering of 
 turning tools require much expe- 
 rience on the part of the workman ; 
 for although they may be of the 
 best possible shape, they are worse 
 than useless unless properly hard- 
 ened. The general process of 
 hardening and tempering tools is 
 as follows : The cutting end of the 
 tool is slowly heated in a clear fire, 
 and when of a light red heat is 
 cooled quickly in water ; it is then 
 very hard and Brittle, and requires 
 tempering or reducing to the pro- 
 per degree of hardness ; to effect 
 this, it is necessary to brighten the 
 part, so that a change of colour 
 may be readily observed, and then 
 place it upon a red-hot bar ; when 
 it has become heated to a certain 
 degree by contact, the bright part 
 will have a pale straw-colour ; this 
 gradually deepens, and when it has 
 arrived at the requisite depth of 
 tint, the tool is removed and again 
 cooled, after which it is fit for 
 use. (See also the article Took.} 
 
 Turnsole, a colour used in painting. 
 
 Turn-table, a circular table, with 
 cross-rails fixed on its surface, sup- 
 ported by rollers, and capable of 
 being turned on a central pivot : 
 used for moving a railway carriage 
 from one line of rails to another. 
 
 Turret, a small tower attached to 
 and forming part of another tower, 
 
 filfi 
 
 or placed at the angles of a church 
 or public building, especially in the 
 style of Tudor architecture. 
 
 Tuscan Style of Architecture. This 
 originated in the north of Italy, on 
 the first revival of the arts in the 
 free cities, and beyond which it has 
 never yet travelled, except in some 
 examples which were introduced 
 by Inigo Jones in the first church 
 of St. Paul, Covent Garden, and by 
 Sir Christopher Wren in porticoes 
 at St. Paul's cathedral, London. 
 It is a simpler variety of the Doric, 
 with unfluted columns and without 
 triglyphs. 
 
 Tuyere. A blast pipe. Before pud- 
 dling became so generally in- 
 troduced, the shape and position 
 of the tuyere at a blast furnace re- 
 ceived considerable attention. The 
 chief purpose of the metallic tuyere 
 is the preservation of the fire-proof 
 hearthstones; the direction and 
 form of the blast are of minor im- 
 portance. This protection is ac- 
 complished, in some measure, by 
 making a coating of fire-clay in the 
 tuytVe-hole which is cut in the 
 hearthstones. By this means, con- 
 stant attendance, and repeated re- 
 newal with clay, the tuyere may 
 be maintained narrow : whether 
 formed of clay or metal, it should 
 never be wider than the nozzle. 
 Where one of the former kind ex- 
 ceeds the width of the nozzle, it 
 burns away, and the earth is ex- 
 posed to destruction. The preser- 
 vation of the original dimensions 
 of the earth is the main object 
 which the manager of a furnace 
 seeks to secure ; and as the clay 
 tuyere does not effect this object, 
 those made of copper or cast-iron 
 have been substituted in its place. 
 These reach further into the fur- 
 nace than those of clay, and there- 
 fore, as it is decidedly of advantage 
 that the blast should be driven as 
 far as possible into the centre of the 
 hearth, the former are much pre- 
 ferable to the latter. If formed of 
 vvrought-iron.theyare liable to burn, 
 
UY 
 
 TUYERE. 
 
 TUY 
 
 as the iron, in consequence of its 
 purity, oxidizes, and forms with the 
 clay around it a veryfusible silicate, 
 which is precipitated into the fur- 
 nace. Grey is preferable to white 
 cast-iron, and also to wrought-iron ; 
 the carbon and impurities it con- 
 tains protect it against oxidation 
 and destruction. Copper is the 
 best metal for tuyeres ; it is a good 
 conductor of heat, and is kept cool 
 by the blast more easily than iron. 
 Its silicates also are infusible. If 
 copper oxidizes and forms a silicate, 
 the latter will protect it. The ad- 
 vantages derived from the copper 
 tuyere have, in Europe, been ac- 
 knowledged for more than a cen- 
 tury; still the charcoal furnaces 
 in America, at which cold blast 
 is employed, are generally blown 
 by clay tuyeres, the result of which 
 is the waste of much coal, and the 
 production of inferior iron. This 
 is mentioned as one of those rare 
 cases in which Americans do not 
 make the best use of the means 
 at their disposal. The copper 
 tuyere is protected against the heat 
 of the furnace by the cold blast, 
 which touches it, and for this rea- 
 son should not be wider than the 
 nozzle. In this point of view, it 
 may be regarded merely as a pro- 
 longation of the nozzle, and is, of 
 course, governed by the rules appli- 
 cable to the latter. So long as pig- 
 iron is to be made by the charcoal 
 forge, the desire to make white 
 plate-iron in the blast-furnace will 
 exist, It is very difficult, almost 
 impossible, to keep a blast-furnace 
 constantly running upon a certain 
 kind of iron ; and therefore the dif- 
 ference which the quality of that in 
 the furnace exhibits is modified to 
 a more or less general standard by 
 means of the position of the tuyere, 
 such as its direction and inclina- 
 tion. Very skilful management is 
 required, in many instances, to pro- 
 duce the desired effect. In some 
 parts of Europe, where cold-blast 
 iron for the forge is manufactured, 
 
 519 J 
 
 the copper tuyere is yet in use ; 
 but where pig-irpn for puddling 
 is made, or hot-blast employed, 
 such close attention is not ne- 
 cessary. In America, the niceties 
 involved in adjusting the tuyere 
 can scarcely be appreciated, not 
 even at the forge fires ; but this 
 adjustment is unaccompanied with 
 any practical convenience, as the 
 trouble it requires is never compen- 
 sated. The advantages which arise 
 from a scrupulous attention are, 
 at best, very small ; and such at- 
 tention would, under the condi- 
 tions which exist in America, es- 
 pecially the high price of labour, 
 result in loss instead of gain. 
 
 At cold-blast furnaces in Ameri- 
 ca, clay or cast-iron tuyeres, prin- 
 cipally the former, are consequently 
 generally employed. Water tuyeres 
 are in use at forges, fineries, hot- 
 blast, and at some cold-blast fur- 
 naces. A common one for the Cata- 
 lan forge, the charcoal forge, finery, 
 and charcoal blast-furnaces.is made 
 of boiler plate. The top part is 
 hollow, while the bottom part, 
 which is generally flat, is solid. A 
 water-pipe, of ^-inch bore, con- 
 ducts a current of cold water 
 through the hollow top : this pre- 
 serves the tuyere, and protects it 
 against burning. The bottom is 
 made flat, so as to serve as a sup- 
 port to the nozzle ; and thus the 
 latter may be readily moved to those 
 places where it is most needed. 
 At blast-furnaces and fineries, this 
 precaution is not of much use, as 
 the nozzle remains at the place 
 where it is fixed ; but at forges it 
 must be movable. Both of the 
 water-pipes are, in most cases, at 
 the top : but this arrangement can 
 scarcely be considered so advan- 
 tageous as though one pipe, or the 
 entrance of the water, were nearer 
 the bottom, and the other pipe, or 
 the outflow, at the top. 
 
 Tuyeres for anthracite, coke, and 
 most of the charcoal furnaces, are 
 perfectly round, and made of boiler 
 
TUY 
 
 TUYERE. 
 
 TUY 
 
 plate ; seldom of copper or cast 
 iron. The tapering of them does 
 not affect the furnace ; and for all 
 the evil this tapering occasions, it 
 may be a perfect cylinder. In 
 using hot blast, it makes no differ- 
 ence how the air is conducted into 
 the furnace, provided the tuyere is 
 kept open, and bright ; which is all 
 that is necessary. The nozzle is 
 laid into the tuyere, how far it 
 reaches into it, is a matter of no 
 consequence, and the space be- 
 tween them filled up with clay. 
 At a cold-blast furnace, it requires 
 some attention not to push the 
 nozzle too far in, or to draw it too 
 far back. The water-pipes are of 
 lead, J-inch, seldom 1-inch bore; 
 one on the lower and the other on 
 the top part of the brim. The 
 lower pipe conducts the water to 
 the tuyere, and the upper one from 
 it. The former is, in many cases 
 pushed as far as possible into its 
 interior, to bring the cold water 
 into the furnace ; and the water is 
 thus applied where the heat is 
 greatest. A constant, uninterrupted 
 supply is necessary to prevent the 
 melting of the tuyere. The water 
 must be pure ; else it will leave a 
 sediment in it which is sure to 
 cause its destruction. There must, 
 also be a sufficient supply of cold 
 water: if the formation of steam 
 is going on in the interior of the 
 tuyrre, the latter is sure to be 
 burned. Copper and brass last 
 longer than iron ; but if iron 
 tuyeres are well made, and sol- 
 dered with copper, and if there is 
 no lack of water, they may last a 
 long time. Where there is a de- 
 ficiency of water, or where there 
 are sediments in the interior of a 
 tuyere, a few hours' heat will de- 
 stroy it. If it be found that they 
 do not wear well, attention must 
 be directed to the water; and if 
 nothing appears wrong, the appli- 
 cation of larger pipes, or higher 
 hydrostatic pressure, will then re- 
 medv the evil. Water tuveres are 
 
 generally from 10 to 20 inches long; 
 those that are too short are liable 
 to be burnt, by the fire working 
 around them, because there is not 
 sufficient room to keep it closed 
 up. Another disadvantage is, that 
 their want of length prevents them 
 from being pushed into the hearth ; 
 but length is necessary when the 
 earth is burned out, and when the 
 blast should be carried further into 
 the interior. The external size is 
 also a matter which requires atten- 
 tion in the construction. The total 
 surface determines the amount of 
 water which is necessary. The 
 larger the surface, particularly the 
 diameter, the greater the amount 
 of water necessary, and of course 
 the greater the danger of burning] 
 A tuyere is seldom more than 
 four inches in diameter inside ; but 
 the diameter outside is sometimes 
 tvvelve,and even more inches. \Vith 
 such an increase of the diameter, 
 however.the danger is augmented. 
 Tuyeres may be considered a pro- 
 longation of the nozzle or the blast- 
 pipe, and disconnected from it 
 merely for the sake of preservation, 
 and of more convenient access to 
 the interior of the furnace. Those 
 for cold blast should taper more 
 than those for hot blast, because 
 the former clinker in a greater de- 
 gree, and require cleaning more 
 frequently than the latter. The 
 more acute the angle of the tuyere, 
 the colder it works ; and the more 
 tapered it is, the hotter it work>. 
 These observations are of practical 
 importance. In most cases the 
 blast is required as far in the in- 
 terior of the furnace as possible, 
 because fuel is thus saved, better 
 iron produced, and the hearth pro- 
 tected. There is some difficulty in 
 giving cold-blast tuyeres a slight 
 taper, because they should be very 
 wide outside; but this difficulty can 
 be overcome by making their in- 
 teriors more curved. If the extreme 
 end, as far back as the diameter of 
 the mouth, is cylindrical, the same 
 
 520 
 
'UY 
 
 TUYERE. 
 
 TUY 
 
 purpose is accomplished as though 
 the whole were cylindrical. If too 
 much tapered, which is shown hy 
 its working too hot, the evil is 
 diminished, in some measure, by 
 pushing the nozzle further into the 
 furnace. This is but a temporary, 
 not a radical remedy; and a tuyere 
 of a proper form must be substi- 
 tuted. If it works too cold, that 
 is, sets on too much cold cinder, 
 the only resource is scrupulously 
 to keep it clean, and to replace it 
 as soon as possible by one more 
 tapered, or with a more obtuse 
 cone. From these considerations, 
 it is evident that different kinds 
 of ore require a tuyere of different 
 taper ; but for the exact degree of 
 this taper no general rule <;an be 
 given. Experience must, in this 
 instance, be the only guide. This 
 will appear more evident on taking 
 into consideration the kind of fuel 
 and the pressure of the blast re- 
 quired. Calcareous ore, as well as 
 the pig-iron made from it, works 
 naturally hot at the tuyere ; conse- 
 quently, those more acute are em- 
 ployed, and serve to<drivethe blast 
 far into the furnace, by which 
 means they are kept cool. This 
 result can be effected by a water 
 tuyere. Clay ores, which work 
 naturally cold, work better with 
 one that is tapered. These consi- 
 derations, which have a special bear- 
 ing upon the working of furnaces 
 and forges, are entirely of a practi- 
 cal nature ; and for this reason the 
 management of the furnace or forge 
 is accompanied with such different 
 results. It is evident that the mo- 
 dification of a tuyere cannot, at 
 times, be so quickly accomplished 
 as may be desired : months, and 
 even years, are often consumed, 
 before the required form can be 
 accurately determined; in many 
 eases, this form is never arrived at. 
 The shape is therefore a matter 
 which, as blast-furnaces, generally 
 depends on the decision of the 
 keeper or founder; and as those 
 
 formed of clay may be altered very 
 conveniently, this may be assigned 
 as one of the reasons why so many 
 of that kind are in use. The whole 
 matter, however, is divested of its 
 mystery, when it is found that an 
 obtuse tuyere tends to work warm, 
 while one more acute produces an 
 opposite effect, and is more advan- 
 tageous as respects both the quality 
 and quantity of work ; but it is more 
 difficult to manage. The form of 
 the nozzle, as well as that of a 
 metal tuyere, is permanent ; and 
 as the advantage of either shape 
 can be arrived at, in a more or less 
 perfect manner, by pushing in or 
 drawing back the nozzle, no solid 
 objection exists agai nst those formed 
 of metal. Some difference should be 
 made between the form of the nozzle 
 and that of the tuyere. An obtuse 
 nozzle should work with the latter 
 more acute: a slightly tapered 
 nozzle, with one greatly tapered. 
 The latter form is generally pre- 
 ferred, on account of the facility of 
 cleaning. 
 
 In applying hot blast, the form 
 of the tuyere and the nozzle is a 
 matter of indifference ; but in their 
 construction it is found desirable 
 to adopt the rules here suggested. 
 The advantages of hot Mast are 
 sometimes doubtful; and it is 
 therefore better to unite, by means 
 of perfect forms of apparatus, all 
 the advantages derivable from the 
 cold blast, and thus to regain what 
 is lost in quantity by its employ- 
 ment. 
 
 In forge fires there are generally 
 but one tuyere and two nozzles. 
 At refinery fires the tuyeres are 
 often all on one side ; at other 
 places on opposite sides. All these 
 differences are the result of local 
 causes, originating in the form of 
 the apparatus, the quality of the 
 iron and fuel, the pressure of the 
 blast, and the qualification of the 
 workmen. Their number and their 
 position in the blast-furnace de- j 
 serve attention. In using cold j 
 
 521 
 
TYI 
 
 ULTRAMARINE. 
 
 ULT 
 
 blast, few should be employed, and 
 in using hot blast as many as pos- 
 sible. Cold-blast tuyeres are natu- 
 rally troublesome ; they are apt to 
 become black, and require constant 
 attention, as well in moving the 
 nozzle as in patching them with 
 clay; they also tend to produce 
 white iron, and they cool the lower 
 parts of the hearth. For these 
 reasons their number should be 
 reduced as much as possible, as 
 the hot-blast tuyere works very hot, 
 occasions but little trouble, is much 
 inclined to produce grey iron, and 
 tends to reduce silex, and conse- 
 quently to produce a poor quality 
 of iron. Therefore, the use of as 
 many hot-blast tuyeres as can be 
 conveniently employed is recom- 
 mended. The position of tuyeres 
 is most favourable when placed on 
 both sides of the hearth. The timp 
 is that part of the hearth which is 
 first burnt out ; and if the tuyere 
 is in the back part of the hearth, 
 the distance from it to the op- 
 posite timp is unnecessarily in- 
 creased. 
 
 Tying, in mining, the term for wash- 
 ing ores. 
 
 Tympan of an arch, a triangular space 
 
 or table in the corners or sides of 
 an arch, usually hollowed, and en- 
 riched with branches of laurel, 
 olive, oak, etc., and sometimes with 
 emblematical figures. 
 
 Tympanum, the triangular panel of 
 the fastigium of any building, com- 
 prehended between its corona and 
 that of the entablature : the panels 
 of a framed door were called tym- 
 pana by the Romans. 
 
 Typhoon is a name frequently applied 
 to a tropical storm : it is also given 
 to the hot winds which occasion- 
 ally blow with great violence in 
 Africa, Syria, Arabia, and Persia ; 
 and which are felt, though rarely 
 and with much diminished force, 
 in the southern parts of Italy and 
 Spain. The sirocco of Egypt and 
 the coasts of the Mediterranean, 
 the simoom of Arabia, and the har- 
 mattan of the coast of Guinea, are 
 understood to be so many desig- 
 nations of the typhoon ; all of 
 them being supposed to originate 
 in the same cause, with modifi- 
 cations depending merely on the 
 nature of the particles exhaled 
 from the ground in the different 
 countries. They are also said to 
 cause water-spouts at sea. 
 
 u. 
 
 . ULTRAMARINE, Lazuline, or Azure,'\s 
 prepared from the lapis lazuli, a 
 precious stone found principally in 
 Persia and Siberia. It is the most 
 celebrated of all modern pigments, 
 and, from its name and attributes, 
 is probably the same as the no less 
 celebrated Armenian blue, or cy- 
 anus of the ancients. Of the lat- 
 ter, Theophrastus informs us that 
 the honour of inventing its factiti- 
 ous preparation (by perhaps a very 
 singular chemico-mechanical pro- 
 cess still used for ultramarine) was 
 ascribed in the Egyptian annals to 
 one of their kings ; and it was so 
 highly prized, that the Phoenicians 
 paid their tribute in it, and it was 
 given in presents to princes ; hence 
 
 522 
 
 it was a common practice, in those 
 times, to counterfeit it. 
 Ultramarine ashes (mineral grey) are 
 the residue of lapis lazuli from 
 which ultramarine has been ex- 
 tracted, and vary in colour from 
 dull grey to blue. Although not 
 equal in beauty, and inferior in 
 strength of colour, to ultramarine, 
 they are extremely useful pigments, 
 affording greys much more pure 
 and tender than such as are com- 
 posed of black and white, or other 
 blues, and better suited to the 
 pearly tints of flesh, foliage, the 
 greys of skins, the shadows of dra- 
 peries, etc., in which the old masters 
 were wont to employ them. Ul- 
 tramarine broken with black and 
 
UMB 
 
 UNIT OF WORK. 
 
 UNM 
 
 white, etc., produces the same ef- 
 fect, and is thus sometimes car- 
 ried throughout the colouring of a 
 picture. The brighter sorts of ul- 
 tramarine ashes are more properly 
 pale ultramarines, and of the class 
 of blue; the inferior are called 
 mineral grey. 
 
 Umber, commonly called Raw Umber, 
 is a natural ochre, abounding with 
 oxide of manganese, said to have 
 been first obtained from ancient 
 Umbria, now Spoleto, in Italy. It 
 is found also in England, and in 
 most parts of the world ; but that 
 which is brought from Cyprus, un- 
 der the name of Turkish umber, is 
 the best. It is of a brown citrine 
 colour, semi-opaque, has all the 
 properties of good ochre, is per- 
 fectly durable both in water and 
 oil and one of the best drying co- 
 lours we possess : it injures no 
 other good pigment with which it 
 may be mixed. 
 
 Undecaffon, a polygon of eleven sides. 
 
 Undercroft, a subterraneous apart- 
 ment or crypt. 
 
 Underlay. When a vein in a mine 
 hides or inclines from a perpendi- 
 cular line, it is said to underlay. 
 
 Underlay shaft, a shaft sunk on the 
 course of a lode. 
 
 Underlayer, in mining, a perpendi- 
 cular shaft sunk to cut the lode at 
 any required depth. 
 
 Undershot wheel, in hydraulics, a 
 wheel with a number of flat boards, 
 which receive the impulse of the 
 water conveyed to the lowest 
 part of the wheel by an inclined 
 canal. 
 
 Uniform motion. The velocity of a 
 moving body is said to be uniform 
 when the body passes over equal 
 spaces in equal times. 
 
 Union screws or joints, in locomotive 
 engines, the brass unions for con- 
 necting the elastic bore-pipe of the 
 tender to the feed : pipe of the en- 
 gine ; smaller ones also connect 
 the tender steam-pipe with the 
 feed-pipe and with the boiler. The 
 feed-pipe is likewise attached to 
 
 the lower end of the pump by a 
 large union screw. 
 
 Unit of work. The measure of any 
 amount of work is the work done 
 where a pressure of 1 Ib. is exerted 
 through 1 foot, the pressure acting 
 in the direction in which the space 
 is described. If instead of 1 Ib. 
 being moved through 1 foot, it be 
 moved through 2 feet, it is clear 
 that the work is doubled, or that 
 two units of work have been done. 
 The difference between the aggre- 
 gate work done upon a machine 
 during any time by those forces 
 which tend to accelerate the mo- 
 tion, and the aggregate work, dur- 
 ing the same time, of those which 
 tend to retard the motion, is equal 
 to the aggregate number of units 
 of work accumulated in the moving 
 parts of the machine during that 
 time, if the former aggregate ex- 
 ceed the latter, and lost by them 
 during that time, if the former ag- 
 gregate fall short of the latter. 
 
 In reference to the unit of time, 
 the unit of mechanical power has 
 been assumed to be 1 Ib. raised 1 ft. 
 high, and 1 minute as the unit of 
 time; the unit of work will there- 
 fore be represented by 1 Ib. raised 
 1 foot high in 1 minute. Now, it 
 is assumed that a horse is capable 
 of doing 33,000 such units of work, 
 i. e. that he is capable of raising 
 33,0001bs. 1 foot high in a minute, 
 or 1 Ib. 33,000 feet high ; and this 
 is called a horse's power, and is 
 the unit of work in reference in 
 the unit of time commonly used in 
 this country. 
 
 Universal chuck, a circular plate to 
 screw on the mandril of a lathe, 
 and hold a nut or any small piece 
 of metal to be bored : in the plate 
 are two or more radial slots, fitted 
 by the jaws or pieces which pro- 
 ject from the face of the chuck, 
 moved by screws towards the cen- 
 tre and tightened upon the nut. 
 
 Unmoor, in navigation, to reduce a 
 ship to the state of riding by a 
 single anchor and cable. 
 
UNS 
 
 VALVES. 
 
 VAL 
 
 Unship, to remove anything out of a 
 ship. 
 
 Urn, an ancient utensil, used for a 
 variety of purposes ; sometimes as 
 the receptacle of lots or for votes 
 at the public election of magis- 
 trates ; but its greatest and most 
 frequent use was as a receptacle 
 for the ashes of the dead after their 
 
 Y. 
 
 VACUUM, a vacuity or space unoccu- 
 pied by matter ; in pneumatics, 
 the vacuum caused by an airpump, 
 which is a degree of rarefaction 
 sufficient to suspend the ordinary 
 effects of the atmosphere. 
 
 Vacuum-pump, a pump connected to 
 the boiler of a marine engine, for 
 charging the boiler with water 
 from the sea by discharging the air, 
 causing the water to rise within the 
 boiler, from the pressure of the 
 atmosphere without; by this means 
 much labour and time are saved, 
 which would otherwise be expen- 
 ded in lifting the vats. 
 
 Fair, a term in heraldry, being a fur 
 composed of four distinct colours ; 
 argent, gules, or, and sable. 
 
 Valve, in hydraulics, etc., a lid con- 
 trived to open one way, to admit a 
 fluid into a tube, but which shuts 
 when pressed from the other, to 
 prevent its return. In anatomy, a 
 kind of membrane which opens in 
 certain vessels to admit the blood, 
 and shuts to prevent its regress. 
 
 Valves, in blast machines, are essen- 
 tial in blast-conducting pipes ; first, 
 for shutting up the blast entirely ; 
 secondly, for diminishing and in- 
 creasing it at pleasure. The first 
 kind is needed where the blast is 
 generated, for various purposes, by 
 the same blast machine. The 
 valves in use are, the sliding, the 
 conical, and the trundle. The 
 two first-named are but little em- 
 ployed. If well made, the latter 
 kind of valve is very useful. At 
 one end it has a handle, and, in 
 many instances, a graded scale, 
 
 524 
 
 bodies were burnt. These urns were 
 sometimes kept in houses, and also 
 put under tombstones, or within 
 vaults or graves. Urns and similar 
 vessels have been found in the bu- 
 rial places of the ancient Britons. 
 In modern times, the urn is an 
 utensil of domestic use. 
 
 which indicates the amount of air 
 which passes through the valve, or, 
 in other words, it shows the open- 
 ing of the valve. At each tuyere 
 or nozzle a valve is required, which 
 serves either to shut off the blast 
 entirely, or to regulate the passage 
 of whatever amount is needed. At 
 the nozzle-valve, a scale is very 
 useful, partly for the purpose of 
 adjusting the blast, and partly for 
 that of fastening the handle of the 
 valve, and keeping it in a certain 
 position. 
 
 The laws which govern the con- 
 struction of blast-pipes, valves, and 
 tuyeres, are summarily as follows: 
 The interior of the blast conductors 
 should be as smooth as possible, 
 as an uneven surface causes great 
 friction. The friction of the air is 
 proportional to the length of the 
 pipe, and to the density of the air 
 which passes through it. It is 
 proportional to the square of the 
 speed of the air, and the reverse of 
 the square of the diameter of the 
 pipe. Obstructions caused by 
 short bends in such pipes are 
 inversely proportional to the angle 
 of the bend, and are governed 
 by the laws of hydrostatics. Sud- 
 den contractions and expansions 
 of the pipe occasion a whirling 
 disturbance in the current of the 
 air a loss of power, or, what is 
 the same, of blast. 
 
 Valve, safety, a valve in a steam-en- 
 gine, to obviate the danger of explo- 
 sion, by allowing the steam to escape 
 when the pressure is raised beyond 
 a certain weight. 
 
VAPORIZATlOiN. 
 
 VAP 
 
 f alve-seat, the flat or conical surface 
 upon which a valve rests. 
 
 Vandyke Brown, a pigment hardly 
 less celebrated than the great 
 painter whose name it bears, is a 
 
 | species of peat or bog-earth, of a 
 fine deep semi-transparent brown 
 colour. The pigment so much es- 
 teemed and used by Vandyke is 
 said to have been brought from 
 Cassel; and this seems to be justi- 
 fied by a comparison of Cassel 
 earth with the browns of his pic- 
 tures. The Vandyke browns in 
 use at present appear to be terrene 
 pigments of a similar kind, purified 
 by grinding and washing over : they 
 vary sometimes in hue, and in de- 
 grees of drying in oil, which they 
 in general do tardily, owing to their 
 bituminous nature, but are good 
 browns of powerful body, and are 
 durable both in water and oil. 
 
 r ane, or Wind-vane, in navigation, a 
 thin slip of bunting; a string of 
 feathers, etc., stuck up to wind- 
 ward, to show the direction of the 
 wind. 
 
 'anes. In Europe, the custom of 
 placing vanes on church steeples is 
 very old ; and, as they were made 
 in the figure of a cock, they have 
 been thence denominated weather- 
 cocks. 
 
 Banning, removing the impurities 
 from tin ore. 
 
 T aporization. The presence of mois- 
 ture in the air is accounted for by 
 a modification of the process of 
 vaporization. Water evaporates, or 
 is converted into steam (by steam 
 we here mean the elastic vapour of 
 water, which is always invisible ; 
 what is 'commonly called steam, 
 but properly cloud, is liquid water 
 in a finely divided or powdered 
 state, wafted like dust by currents 
 of air, or of steam properly so 
 called) at all temperatures, until 
 the whole space above it, whether 
 containing air or not, is pervaded 
 with watery vapour of a certain 
 fixed density and elasticity, de- 
 pending on the temperature, and 
 
 connected therewith by certain 
 laws. The elasticity or expansive 
 tendency of a fluid is estimated by 
 the number of pounds or ounces 
 with which it presses on each 
 square inch of surface that it 
 touches ; or by the number of 
 inches of mercury that it will sup- 
 port, as on a barometer. 
 
 Steam can exist at any given 
 temperature, and of such 'density 
 as to have a certain fixed pressure, 
 and no more; and (if there be 
 water enough present) steam will 
 be accumulated till it has this 
 density ; but no more can then 
 be accumulated without raising 
 the temperature : aad if the tem- 
 perature be lowered, a portion of 
 the steam will immediately become 
 water, so that (occupying in this 
 state some thousands of times less 
 space than before) it may leave room 
 for the remaining vapour to expand, 
 till its expansive force is reduced 
 to that which the new temperature i 
 can support. The pressure of steam 
 is therefore always the same at the 
 same temperature. At 212 its 
 elastic force is equal to that of the 
 atmosphere, and it will support a 
 column of mercury 30 inches high, 
 which is the reason that boiling j 
 requires this temperature in the | 
 open air, when the barometer is at 
 30 inches ; but rather less or more, 
 when the barometer stands lower 
 or higher. Above this temperature 
 it becomes high-pressure steam, 
 which at 220 will support nearly i 
 35 inches of mercury ; at 230. 
 nearly 42 inches, and so on. But { 
 the steam which is thrown off | 
 from the waters of the earth, from I 
 damp soil, from the foliage of plants, \ 
 and even from ice and snow, has i 
 but a very small pressure. Steam 
 at 32 will support only 0*200 of 
 an inch of mercury ; at'40, 0-263 
 of an inch ; at 50, 0'375 of an inch; 
 at 60, 0-524, or rather more than j 
 half an inch of mercury ; at 80, j 
 it will support one inch, and so on. 
 When the air contains as much 
 
VAR 
 
 VELOCIMETER. 
 
 VEL 
 
 vapour as can exist at the existing 
 temperature, it is said to be satu- 
 rated. If in this state it experience 
 the smallest reduction of tempera- 
 ture, some of the vapour must im- 
 mediately become liquid, assuming 
 the form of cloud, fog, or rain. 
 These effects depend on the cool- 
 ing of the air below the tempera- 
 ture necessary to retain all its 
 vapour. But when a solid body 
 is cooled below this temperature 
 (the air remaining above it), a dif- 
 ferent kind of deposition occurs, 
 called dew, which does not fall in 
 drops from the air, but grows, as 
 it were, on the solid. Dr. Wells 
 proved, by a most complete investi- 
 gation of this subject, that instead 
 of dew cooling bodies, as commonly 
 supposed, it is their cooling which 
 causes dew ; and its formation even 
 mitigates the cold, by the heat 
 previously latent, which the steam 
 gives out on condensing into water. 
 The degree of heat at which dew 
 begins to be formed is called the 
 dew-point, and instruments called 
 hygrometers have been invented to 
 measure it. The difference between 
 the temperature of the dew-point 
 and the temperature of the atmo- 
 sphere indicates the degree of dry- 
 ness, which in this country seldom 
 reaches 30 ; that is, the tempera- 
 ture of the earth necessary to con- 
 dense the vapourof the air is seldom 
 30 below the temperature of the 
 air. In India it has been known 
 to be 61 below it, and in Africa 
 probably lower still. 
 
 If, while dew is forming, the 
 earth continues to cool down until 
 it reaches the freezing-point, hoar- 
 frost is formed. The beautiful 
 figures seen in winter on the inner 
 surface of window panes, cooled 
 by the external air, are produced 
 by these cold surfaces condensing 
 the moisture of the warmer air 
 within. 
 
 Varry, a term in heraldry, denoting 
 the mixture of argent and azure 
 together. 
 
 Varry, cuppy, a term applied to a fur 
 of cups. 
 
 Vat, a wooden tub, used to wash ores 
 and mineral substances in; a work- 
 ing-tub of any kind. 
 
 Vault, in architecture, an arched roof, 
 so contrived as that the several 
 stones by their disposition shall 
 support each other. 
 
 Veering, or Wearing, in 'navigation, 
 the operation to which a ship, in 
 changing her course from one 
 board to the other, turns her stern 
 to windward, in opposition to 
 tacking, wherein the bow is turned 
 to the wind and the stern to lee- 
 ward. 
 
 Vein, a course of metal in a mine : 
 a rake vein is perpendicular or 
 nearly so; a pipe vein, nearly hori- 
 zontal. 
 
 Vein, in mining, to wash or cleanse a 
 small portion of ore in a shoal. 
 
 Velocimeter, an apparatus for measur- 
 ing the rate of speed of machinery. 
 When the velocity is uniform, the 
 instrument is merely a measurer of 
 distance; but this is not the case 
 with a variable velocity, which 
 requires a much more elaborate 
 contrivance for its estimation. Such 
 a velocity-measurer was constructed 
 by Breguet, of Paris, under the di- 
 rection of M. Morin, the principle 
 of which may be briefly explained 
 as follows : A circular disc, covered 
 with card or paper, is made to 
 revolve with a uniform motion 
 by means of clock-work, regulated 
 by air-vanes : upon this disc, a 
 revolving pencil, whose motion is 
 caused by and corresponds with 
 that of the body whose variable 
 velocity is to be measured,describes 
 a curved line ; and from this curve, 
 which results from a combination 
 of the variable with the uniform 
 motion, the velocity may be easily 
 ascertained %y processes and for- 
 mulae adapted to the purpose. One 
 of these cards, with the curve 
 traced on it by the piston of the 
 Cornish steam-engine at Old Ford, 
 is engraved in the ' Transactions of 
 
 526 
 
VEL 
 
 VELOCITY. 
 
 VEL 
 
 the British Association for the Ad- 
 vancement of Science.' This beau- 
 tiful and ingenious contrivance, by 
 which spaces described in the ten- 
 thousandth part of a second may 
 be easily discerned, is the invention 
 of M. Poncelet, and was carried 
 into execution by M. Morin. 
 
 The instrument, when put in 
 order, was first tried at King's 
 College, London, a variable motion 
 being given by a small carnage 
 made to descend an inclined plane. 
 The correspondence of the velocity 
 shown by the machine with that 
 deduced by the known laws of 
 dynamics, was such as to give great 
 confidence in its accuracy. After a 
 few minor alterations, suggested by 
 frequent trials, it was removed to 
 the East London Water-works, and 
 attached to the Cornish engine at 
 work there, from which several 
 diagrams were taken ; and the 
 velocities calculated from these 
 have been expressed in the form of 
 geometrical curves, whose abscissaj 
 represent the spaces passed over 
 by the piston of the engine, and 
 whose originates indicate the corre- 
 sponding velocities at the different 
 points of the stroke. 
 
 Velocipede, a carriage which is capa- 
 ble of being propelled along a road 
 by the muscular power of the rider 
 acting upon treadles and levers 
 which communicate with a cranked 
 wheel axle. 
 
 Velocity, in dynamics, is the ratio of 
 the quantity of linear extension 
 that has been passed over in a 
 certain portion of time; or it is 
 the ratio of the time that has been 
 employed in moving along a deter- 
 minate extension. 
 
 When a man ascends vertically, 
 his velocity is reduced to about 
 one-half of his horizontal velocity, 
 indicating that he acts against a 
 double resistance ; therefore, when 
 a man ascending a ladder carries 
 a load, the maximum effect will take 
 place when his ascending velocity 
 is about one-fourth of the velocity 
 
 he can walk horizontally without a 
 load. 
 
 A man of ordinary strength will 
 not be able to walk, unloaded, at a 
 quicker rate than 3| miles an hour, 
 if this exertion is to be continued 
 for 10 hours every day. Indeed, 
 those who examine the subject 
 with a view to a fair average, will 
 find this to be about the extreme 
 velocity that can be continued, 
 without injury, for any considerable 
 time ; therefore a man ought to 
 move with half this velocity to 
 produce a maximum effect; that 
 is, at the rate of If mile an hour, 
 which is about 2^ feet per second. 
 
 But this supposes the whole load 
 to be the useful effect, whereas 
 part of it must consist of the 
 apparatus employed to carry it, or 
 the friction of the intermediate 
 machine, or other circumstances 
 of a like nature. About one-fifth 
 of the velocity may be considered 
 equivalent, at an average, to the 
 force lost in friction, etc., in all 
 cases ; in many it will exceed one- 
 fifth. Hence the maximum of 
 useful effect will take place when 
 the velocity is 2 feet per second, 
 or about 11 furlongs an hour, 
 continued for 10 hours each day. 
 
 Smeaton is said to have made 
 numerous comparisons, from which 
 he concluded that the mechanical 
 power of a man is equivalent to 
 3750 Ibs. moving at the velocity of 
 one foot per minute; and taking 
 this average to be near the true 
 one, as there is reason to conclude 
 it is, we have 
 
 3750 
 2T60 =31 ' 251bs - 
 
 Therefore, we make the average me- 
 chanical power of a man 31 -25 Ibs. 
 moving at the velocity/ of 2 feet 
 per second, when the useful effect 
 is the greatest possible ; or half 
 a cubic foot of water raised two 
 feet per second ; a very convenient 
 expression for hydrodynamical in- 
 quiries. 
 
VEL 
 
 VENETIAN SCHOOL. 
 
 VEX 
 
 If a man ascend a vertical ladder* 
 according to a preceding remark, 
 the velocity which corresponds to 
 the maximum of useful effect will 
 be 1 foot per second, and the load 
 double that which he carries hori- 
 zontally ; consequently the average 
 of useful effect is 62-5 Ibs. raised 
 one foot per second. 
 
 Bricklayers' labourers in London 
 ascend ladders with a load of about 
 80 Ibs. besides the hod ; sometimes 
 at the rate of one foot per second, 
 but more frequently about 9 inches 
 per second. 
 
 Ascending stairs is more trying 
 to the muscles of the legs than 
 ascending a ladder: and therefore 
 the useful effect is less, till a per- 
 son has Income accustomed to this 
 kind of labour: and it is also to 
 be observed that the space moved 
 over is increased, unnecessarily, 
 except where the horizontal dis- 
 tance is part of the path over which 
 the load is to be moved. 
 
 The force of a horse is, at an 
 average, about equal to that of six 
 men, according to various esti- 
 mates ; and the rate of travelling 
 about the same, perhaps rather 
 less than that of a man, when his 
 exe-tion is continued for 8 hours : 
 consequently the velocity corre- 
 sponding to the maximum effect 
 will be about 2 feet per second. 
 Whence, the average mechanical 
 power of a horse may be estimated 
 at 187^ Ibs. moving with a velocity 
 of 2 feet per second, or 3 cubic 
 feet of water raised 2 feet per se- 
 cond; the day's work being 8 hours. 
 Velocity of motion. The following is 
 a list of the velocities of moving 
 bodies, extracted from Peschel's 
 ' Elements of Physics,' etc. 
 
 Feet per second. 
 
 Rivers .... 3-4 
 A very rapid stream . ^. 13 
 Wind (ordinary) . . 10 
 
 Storm .... 54 
 
 Hurricane . . . 80-120 
 Sound (through air) . . 1100 
 
 528 
 
 697 
 
 Feet per iecond. 
 
 Sound (through metal) . 12,000 
 Air into a vacuum . . 1280 
 Ball from air-gun (air con- "I 
 
 densed 100 times) . J 
 
 Musket-ball . . .1280 
 Rifle-ball (at most) . .1600 
 Cannon-ball (24-pounder) . 2450 
 Earth's rotation (at equator) 1525 
 
 centre (in its orbit) 101,061 
 Miles per hour. 
 
 Race-horse ... 60 
 
 Pigeon . . . .20-30 
 Peregrine falcon . . 120 
 Ocean steamer . . . 12 
 
 River steamers ... 22 
 
 Railway train ... 80 
 
 Sailing vessel ... 10 
 
 Malay proa . . , 20 
 
 Miles per second. 
 
 Light . . . .200,000 
 Electricity . . .576,000 
 
 Velvet painting is the art of colouring 
 on velvet with transparent liquid 
 and other ready diluted colours, 
 compounded anil made up with 
 various acids, alkalies, etc., accord- 
 ing to their nature and qualities. 
 
 Venetian school. This school would 
 have required no further illustra- 
 tion from any other pen had Si- 
 gnor Antonio Zanetti, in his work 
 upon Venetian painting, included 
 a more ample consideration of the 
 artists of that State. Ridolfi and 
 Boschini also furnish copious ma- 
 terials. 
 
 It is said that Antonello da 
 Messina having been instructed in 
 the secret of colouring in oils by 
 Giovanni Van Eyck, in Flanders, 
 received a public salary, and then 
 he divulged the method of painting 
 in oils to the Venetian professors ; 
 this appears from superscriptions 
 attached to his pictures to have 
 taken place about the year 1474. 
 
 The colours of these artists (those 
 preceding Titian and Giorgione) are 
 simple and natural, though not 
 always in union, more especially 
 with the ground, nor sufficiently 
 broken bv the chiaroscuro. 
 
YEN 
 
 VENTILATION. 
 
 YEN 
 
 In seeking the cause of their 
 superiority it is to be remarked 
 that it was a common practice in 
 Titian's time, to prepare with a 
 chalk-surface the altar-pieces and 
 pictures which were to be executed ; 
 and that white ground, favourable 
 to every variety of tint the paint- 
 er could lay upon it, equally fa- 
 voured the production of a certain 
 polish, floridity, aud surprising 
 transparency. 
 
 The harmony of colours was 
 not better understood by any other 
 artists, insomuch that the mode of 
 assimilating and of contrasting 
 them, may be considered as the 
 second source of the delightful and 
 lively, so predominant in their 
 works, and more especially in those 
 of Titian and his contemporaries. 
 
 Such skill was not merely con- 
 fined to the fleshy parts, in whose 
 colour the disciples of Titian have 
 so far excelled every other school, 
 it extended also to the drapery. 
 For, indeed, there are no pieces 
 of velvets, of stuffs, or of crapes, 
 which they did not imitate to per- 
 fection. 
 
 Titian is universally considered 
 the founder of the Venetian school 
 of painting. Some of the principal 
 masters of this school are 
 
 Giorgione . b. 1477, d. 1511. 
 
 Sebastiano del 
 
 Piombo . b. 1485, d. 1547. 
 
 Pordenone . b. 1484, d. 1MO. 
 
 Titian . . b. 1477, d. 1576. 
 
 Tintoretto . b. 1512, d. 1594. 
 
 (JacopodaPonte)-l b d 59 
 
 Bassano . J 
 
 Paul Veronese . b. 1528, d. 1581. 
 Tiepolo . . b. 1693, d. 1769. 
 
 Venetian Red or Scarlet Ochre. True 
 Venetian red is said to be a native 
 ochre, but the colours sold under 
 this name are prepared artificially 
 from sulphate of iron, or its resi- 
 duum in the manufacturingof acids. 
 They are all of redder and deeper 
 hues than light red, are very per- 
 manent, and have all the proper- 
 
 529 
 
 ties of good ochres. Prussian red, 
 English red, and rouge de Mars, 
 are other names for the same pig- 
 ment. 
 
 Ventilation and warming of buildings 
 is a twofold purpose that should 
 enter into the constructive design 
 of all edifices intended for the resi- 
 dence or occasional congregation 
 of human beings. The necessity 
 for this purpose arises from the 
 fact that the breathing of air (as 
 one of the functions of animal life) 
 renders it unfit for re-inspiration, 
 the lungs retaining the vital pro- 
 perties and emitting the remainder, 
 which consists of ingredients detri- 
 mental to health, and even de- 
 structive of life itself. In order to 
 keep an apartment in a healthy 
 and pleasant condition, fresh air 
 should be constantly supplied at a 
 temperature from 60 to 65, and 
 the vitiated air should be as con- 
 stantly removed ; and all the varied 
 schemes which have been pro- 
 pounded for ventilating buildings 
 have this common purpose of con- 
 stant supply and removal. The 
 vitiated air, on being emitted from 
 the mouth, has a temperature be- 
 tween 80 and 90 ; and as the url- 
 versal effect of heat, manifested in 
 the increase of temperature of the 
 supply, 60 or 65 to 80 or 90, 
 is to expand and enlighten, the viti- 
 ated air has a natural tendency to 
 rise to the upper part of the room. 
 To allow this action to proceed, it 
 is evidently necessary that means 
 for its escape to the top should be 
 provided, and also that fresh air 
 should be introduced at the lower 
 portion of the apartment. The 
 operation would, however, be nulli- 
 fied if the heated air, on emerging 
 from the top of the room into a 
 shaft or chimney intended to con- 
 duct it away, were met by a down- 
 ward current of cold air ; and it has 
 therefore been deemed advisable to 
 provide not only such a shaft or 
 chimney, but also some means, by 
 stoves or other apparatus, of arti- 
 
YEN 
 
 VENTILATION. 
 
 VEN 
 
 ficially heating the air in the shaft 
 and thus assisting the escape of 
 the foul air. And further, in order 
 to secure the constant accession of 
 fresh air and give sufficient impulse 
 to it to overcome any tendency 
 that might be created to oppose 
 its introduction by a retrograde 
 movement of the atmosphere of 
 the building, means have been 
 adopted of forcing this fresh air 
 in with fans or bellows. But these 
 two sets of apparatus have been 
 seldom combined. Those who have 
 adopted the shaft have usually con- 
 temned the fan, trusting to the 
 sucking action of the former to 
 draw off all the vitiated air, and 
 concluding that fresh air must enter 
 as rapidly to fill its place; and, 
 on the other hand, the adopters of 
 the fan decry the addition of the 
 heating apparatus in the shaft, and 
 contend that its only effect is to 
 draw down foul air for its own 
 supply, and to impede the upward 
 current created by this fan. This 
 effect should be obviated in a well- 
 acting apparatus, which would then 
 doubtless assist the fan in pro- 
 1'ioting the continual passage of 
 pure air throughout the building. 
 The objection which has been en- 
 tertained against the use of the 
 shaft without the fan, or some 
 other adequate forcing apparatus, 
 is well-founded on the well-known 
 elasticity of the atmosphere, by 
 which it is susceptible of rarefac- 
 tion to a considerable extent. The 
 heated shaft consequently acts as a 
 pump in sucking the warmed air 
 upwards, and if no force is in ac- 
 tion from below to drive this air 
 upward by the pressure of fresh 
 air entering the apartments, the 
 atmosphere becomes rarefied to a 
 degree which is both unpleasant 
 and prejudicial to sentient exist- 
 ence. It is therefore essential that 
 
 the two processes of exhaustion 
 and supply shall proceed simul- 
 taneously, and be so regulated that 
 no rarefaction shall be suffered in 
 
 530 
 
 the air to be breathed. The pur- 
 pose of warming the air in winter, 
 and of cooling it in summer, that 
 is, more properly, of attemperating 
 it, should be sought, and may be 
 attained conjointly with that of 
 ventilation ; and one of the best 
 arrangements yet carried out for 
 these combined objects is pre- 
 sented in the system adopted at 
 the Reform Club-house in London. 
 The supplying apparatus there em- 
 ployed consists of a large fan which 
 revolves rapidly in a cylindrical 
 case, andis adapted to throw 1 1,000 
 cubic feet of air per minute into a 
 spacious subterranean tunnel under 
 the basement story of the building. 
 This fan is driven by a steam- 
 engine of 5-horse power, working 
 expansively. It is placed in a vault 
 in front of the building, and as it 
 burns anthracite coal and cinders 
 from the house flues, is not pro- 
 ductive of any nuisance or offensive 
 smoke. The steam of condensa- 
 tion supplies three chests, con* 
 structed of cast.iron, with the heat 
 requisite for warming the building. 
 Each of these chests is a cube in 
 form, and measures 3 feet ex- 
 ternally, and is internally divided 
 into seven parallel cases, each 3 
 inches wide, and separated by al- 
 ternate parallel spaces of similar 
 width, for the passage of the air as 
 it is impelled by the fan. By this 
 economical arrangement, which 
 thus makes good use of the steam 
 of condensation, 2 cwt. of fuel is 
 sufficient for working the engine 
 during twelve hours, the engine 
 being besides available for pumping 
 water for the purposes of the 
 establishment, and raising coals to 
 the several apartments on the upper 
 stories. The air in passing through 
 the cells between the steam cases 
 is heated to a genial temperature 
 of from 75 to 85, and thence 
 enters a chamber of brickwork in 
 the basement, from which it is ad- 
 mitted into several distinct flues, 
 regulated by dialled valves or re- 
 
YEN 
 
 VERMILION. 
 
 VIA 
 
 gisters, and thus conducted in any 
 required quantities to the several 
 apartments of the building. A 
 stove is placed in the top story, 
 and is formed as a rectangular 
 chest of cast-iron, contracted above 
 into a round pipe, which discharges 
 the burnt air and smoke into a 
 series of horizontal cast-iron pipes, 
 about 4 inches in diameter, which 
 traverse the room beneath the 
 ceiling and terminate in a brick 
 chimney. One advantage of such 
 an apparatus as is here described 
 would be that of introducing cool 
 air during sultry weather, for 
 which purpose it might be readily 
 adapted. 
 
 Ventilator, a machine made to turn 
 with the wind, and placed in a 
 wall or roof, in order to throw a 
 due quantity of fresh air into a 
 close apartment. 
 
 Verdoy, a term in heraldry, applied 
 when a border is charged with 
 leaves, fruits, and flowers, and like 
 vegetables. 
 
 Verye, a rod, wand, or Serjeant's 
 mace ; also the compass about the 
 king's court that bounds the juris- 
 diction of the lord steward of 
 the king's household, and of the 
 coroner of the king's house, and is 
 accounted 12 miles' compass ; also 
 a rod whereby one is admitted 
 tenant, holding it in his hand and 
 swearing fealty to the lord of the 
 manor, and for that cause called 
 tenant by the verge. 
 
 Verge, a small ornamental shaft in 
 Gothic architecture. 
 
 Vermiculated, chequered ; continuous ; 
 embroidered with several colours. 
 
 Vermile, a cloth or napkin on which 
 the face of Christ is depicted, de- 
 rived from the incident related of 
 St. Veronica. 
 
 Vermilion, a sulphuret of mercury, 
 which, previous to its being le- 
 is called cinnabar. It is ! 
 
 an ancient pigment, and is found 
 in a native state, and produced 
 artificially. Vermilion probably 
 obtained its name from resem- 
 
 531 
 
 blance to or admixture with the 
 beautiful though fugitive colours 
 obtained from the vermes, or in- 
 sects which yield carmine. 
 
 Vernier, a graduated movable index, 
 used for measuring minutely the 
 parts of the space between the 
 equidistant divisions of a graduated 
 scale. 
 
 Versed sine of an arc, in geometry, 
 the position of the diameter in- 
 tercepted between the sine and the 
 commencement of the arc. 
 
 Vert, in heraldry, a green colour ; 
 in the ancient forest laws, every- 
 thing that grows and bears a green 
 leaf within the forest that may 
 cover and hide a deer. 
 
 Vestiary, a wardrobe, or place to lay 
 clothes or apparel in. 
 
 Vestibule, in architecture, the porch 
 or the first entrance of a house. 
 
 Vestibulum, part of the andronitis of 
 a Greek house, similar, probably, 
 to the prostas of the first peristyle 
 or court. 
 
 Vestment, a set of hangings for the 
 service of an altar ; and also a suit 
 of robes for a priest. 
 
 Via (Latin), by way of; in the tune 
 of the Romans, a road or a right 
 of road. Two shallow trenches 
 were commonly dug parallel to 
 each other, marking the breadth 
 of the proposed road : this in the 
 great lines, such as the Via Appia, 
 the Via Flaminia, the Via Valeria, 
 etc., is found to have been from 13 
 to 15feet, on the Via Tusculana 11; 
 while those of less importance, 
 from not being great thorough- 
 fares, such as the via which leads 
 
 . up to the temple of Jupiter La- 
 tialis. on the summit of the Alban 
 Mount, and which is to the present 
 time singularly perfect, seems to 
 have been 8 feet wide. 
 
 Viaduct, a term applied to extended 
 constructions of arches or other 
 artificial works to support a road- 
 way, and thus distinguished from 
 aqueducts, which are similar con- 
 structions to support waterways. 
 This term has become much more 
 
VIA 
 
 VIADUCT. 
 
 VIA 
 
 familiar within the present cen- 
 tury, in consequence of the great 
 numher of vast structures so de- 
 signated which have been erected 
 in various parts of Great Britain 
 for the purpose of carrying rail- 
 ways over valleys and districts of 
 low level : but the general name 
 of viaduct is now recognized as 
 applicable to all elevated roadways 
 for which artificial constructions of 
 timber, iron, bricks, or stonework 
 are established; and accordingly 
 among the principal railway-works 
 are to be enumerated viaducts of 
 all these materials. The vast di- 
 mensions of some of these struc- 
 tures are not more striking to the 
 casual observer, than their great 
 strength, as particularly adapted to 
 railway traffic, is apparent upon a 
 careful study of their construction. 
 The several members of a viaduct 
 are the same as those of a bridge ; 
 indeed the former structure may 
 he considered as an extended bridge, 
 frequently resorted to in situations 
 where no water is to be crossed. 
 The necessity which is imperative 
 in the construction of railways for 
 preserving a horizontel level for the 
 roadway, or at least departing from 
 this level within very restricted 
 limits, imposes the raising of the 
 railway surface in many places, and 
 to a considerable extent above the 
 natural level. Various considera- 
 tions arise as to the preferable 
 mode of effecting this raising, 
 whether by solid embankments of 
 earthwork or by an open or arched 
 structure of other materials. Em- 
 bankments of earthwork are often 
 liable to subsidence from want of 
 cohesion in the materials, or the 
 effect of long-continued rains ; and 
 if free from actual danger arising 
 from these liabilities, they are al- 
 ways sources of much constant ex- 
 pense in making up the surface to 
 the required level, to compensate 
 for the continual depression caused 
 by the passage oi' heavy loads over 
 them. As a question of economy, 
 
 532 
 
 therefore, viaducts are often to be 
 preferred, since their repairs in- 
 volve less expense than those of 
 embankments. It must also be 
 considered that the latter, owing to 
 their necessary extension of base, 
 cover a much wider portion of 
 ground than viaducts, and at the 
 same time cover it in a more ab- 
 solute and objectionable manner. 
 A solid embankment, like a black 
 line across a picture, spoils a beau- 
 tiful landscape, and often precludes 
 all view beyond it from sites 'which 
 otherwise would command an ex- 
 tended range. If the sub-forma- 
 tion of the valley be of a very loose 
 and boggy nature, embankments 
 are scarcely admissible, nor, if the 
 height to be raised exceeds 30 or 
 40 feet, can they be entertained. 
 Indeed, in the majority of cases, 
 valleys, whether having rivers of 
 magnitude or not, are more eco- 
 nomically crossed upon viaducts 
 than embankments. 
 
 Whatever the materials of the 
 structure or its finished design, the 
 same points are to be observed in 
 the construction ; and the first of 
 these is the strength and durability 
 of the foundations. A substantial 
 and permanent character should 
 always be secured for these, even 
 if the superstructure is intended to 
 aim at cheapness rather than so- 
 lidity. It is often requisite that 
 piers and abutments be constructed 
 upon piling, a form of foundation 
 adapted, if thoroughly executed, 
 to afford the most secure basis ; but 
 if done carelessly and insufficiently, 
 liable to involve the most destruc- 
 tive failures. The citation of a 
 few of the most extended works 
 of this class, of modern date, will 
 best show the details of the present 
 approved kinds of construction. 
 
 Of timber viaducts, two fine ex- 
 amples of similar construction are 
 presented on the line of the New- 
 castle, North Shields, and Tyne- 
 mouth Railway. One of these 
 works, which crosses the Ouse 
 
VIA 
 
 VIADUCT. 
 
 VIA 
 
 bourn, besides a public roadway, a 
 mill race, and the adjacent valley, 
 consists of five spans or arches of 
 timber-work, and four end arches 
 of masonry. Of the former arches, 
 three are 116 feet wide in the 
 clear, and two 114 feet. Two of 
 the end arches are 43 feet span, 
 and the other two 36 feet. The 
 height of the rails above the bed 
 of the bourn is 108 feet. The 
 width of the structure allows 26 
 feet for a double line of rails, and 
 5 feet for a footway. The total 
 length of the viaduct is 918 feet, 
 and the two middle piers are 
 erected upon piles, from 21 to 27 
 feet in length. All the piers are 
 of masonry, and tapered upwards, 
 the principal being 21 feet wide 
 above the footings, and 15 feet at 
 the springing of the arches. The 
 piers are continued upwards, of 
 reduced dimensions, to the level 
 of the roadway, the whole of the 
 five main arches, spandrilling, and 
 superstructure, being formed of 
 timber. The radius of these arches 
 is 68 feet, and their rise or versed 
 sine about 33 feet. The ribs form- 
 ing the arches are composed of 
 planks of Kyanized Dantzic deal, 
 the lengths of which vary from 
 20 to 46 feet, by 11 inches wide, 
 and 3 inches thick. These planks 
 are so arranged, that the first 
 course of the rib is two wuole 
 deals in width, the next is one 
 whole and two half deals, the 
 joints being crossed longitudinally, 
 as well as in the depth. The 
 thickness of each rib is made up 
 of fourteen deals, which are bent 
 over a centre to the required form, 
 and fixed together with oak tre- 
 nails, 1$ inch in diameter, placed 
 4 feet apart, and each trenail per- 
 forating three of the deals. Be- 
 tween the joints a layer of strong 
 brown paper is placed, previously 
 dipped in boiling tar. The span- 
 drils are formed of trussed fram- 
 ing ; and the platform of the road- 
 way, which is composed of 3-inch 
 
 planking, is supported upon trans- 
 verse beams laid 4 feet apart. The 
 platform is covered with a com- 
 position of boiling tar and lime, 
 mixed with gravel in applying it, 
 thus forming a coating impervious 
 to water. 
 
 There are several other modes 
 of constructing timber viaducts, 
 without introducing the arches, 
 composed of planks curved into 
 proper form, and which, being laid 
 together like leaves, as just de- 
 scribed, have obtained for this kind 
 of construction the name of the 
 ' laminated bridge.' In other forms 
 of timber viaducts, the requisite 
 strength is obtained by trussing, 
 the peculiar description and com- 
 plication of which depends, of 
 course, mainly on the extent of 
 the span or width of each lay of 
 which the entire structure consists. 
 Whre a great width of clear open- 
 ing is required, a system of diagonal 
 bracing offers peculiar advantages, 
 being susceptible of any desired 
 strength and rigidity. A viaduct 
 of great extent, built upon this 
 principle, is on the line of the 
 Richmond and Petersburg Rail- 
 way, North America. The length 
 of this structure is 2,900 feet, and 
 the trusses are supported upon 
 eighteen granite piers, the dis- 
 tances between which vary from 
 130 to 153 feet. They are founded 
 on the granite rock, and are 40 feet 
 high above the water. The depth 
 of the truss frames (which are ho- 
 rizontal on top and bottom) is 20 
 feet. Another work of the same 
 kind crosses the Susquehannah, 
 and is 2, 200 feet in length, divided 
 into spans of 220 feet each. 
 
 Of viaducts formed of brickwork 
 and masonry, that named the 
 ' Avon viaduct,' on the line of the 
 North-western Railway, may be 
 mentioned. This consists of nine 
 semi-elliptical arches, 24 feet in 
 span, and 7 feet 6 inches rise, and 
 three semicircular arches at each 
 end of 10 feet span. This viaduct 
 
VIA 
 
 VILLAS OF THE ANCIENTS. 
 
 VIL 
 
 is entirely faced with stone, the 
 interior of the work heing of brick. 
 The end arches have brick invert 
 between the piers above the foun- 
 dations, which are laid uniformly 
 in a solid bed beneath these arches, 
 with steps according to the nature 
 of the substratum. An invert of 
 brickwork is built to the three 
 middle arches, forming an artificial 
 channel for the river, and faced at 
 each end with a row of sheet pil- 
 ing, driven through the loam into 
 a bed of strong gravel beneath. 
 All the foundations which do not 
 reach the gravel are laid upon beds 
 of concrete, and a layer of the 
 same material covers the extrados 
 of the arches, and forms a level 
 bed for the gravel in which the 
 sleepers of the railway are bedded. 
 Many similar works of much more 
 extended dimensions have been 
 erected for railway communication. 
 One of these, of peculiarly light 
 appearance, is known as the 'Vic- 
 toria Bridge,' and built over the 
 valley of the river Wear, on the 
 line of the Durham Junction Rail- 
 way. This work consists of two 
 main arches, one 160 feet span, 
 the other 144 feet, two others, 
 each 100 feet span, and six end 
 arches of 20 feet span. The height 
 of the parapet above the high- 
 water level at spring tides is 125 
 feet, and all the arches are semi- 
 circular. The central pier is 23 
 feet 9 inches in width, and 69 feet 
 high from bottom of footings to 
 springing of arches. The two con- 
 tiguous piers are 21 feet wide, one 
 50 feet, the other 52 feet high. 
 The height of the parapet above 
 the springing line of the two main 
 arches is 78 feet. A viaduct, re- 
 cently constructed over the Moine, 
 at Clisson, near Nantes, in Brit- 
 tany, is worth notice, for a pecu- 
 liarity in its construction, which, 
 although not strictly new, is to be 
 found in very few examples. This 
 peculiarity is, that the piers are 
 pierced with a pointed arch, which 
 
 intersects the cylindrical sorh't ol 
 the main arches in the direction ol 
 the length of the viaduct, so that 
 the roadway is supported upon a 
 groined vault, which, seen from 
 the abutments, has the appearance 
 of the aisle of a Gothic cathedral. 
 This viaduct consists of fifteen 
 arches, and is 348 feet in length. 
 The abutments rest upon a granite 
 foundation, the structure itself 
 being constructed of a fine white 
 granite, and the stones of large 
 size. The foundations are 6 feet 
 below the bed of the river, the 
 height from which to the springing 
 line of the arches being 33 feet, 
 and the total height from the 
 foundation to the top of the pa- 
 rapet 61 feet. 
 
 Vibration, the regular reciprocating 
 motion of a body, as a pendulum, 
 musical chord, etc. 
 
 Vice, a tool for holding a piece of 
 metal, while operating upon it, In- 
 placing it between two jaws or nip- 
 pers, and screwing them towards 
 each other. 
 
 Vice-bench, the bench to which a 
 vice is fixed. 
 
 Villa, among the Romans, a farm or 
 country house. 
 
 Villa rustica, a tasteful country resi- 
 dence. See Parker's work, in 4to. 
 
 Villa urbana, a residence so called by 
 the Romans, because its interior 
 arrangements corresponded princi- 
 pally with those of a town house. 
 
 Villas of the ancients. Varo Colu- 
 mella says, "An estate should be in 
 a wholesome climate and fruitful 
 country ; one part champaign, and 
 the other hilly, with easy descents 
 either to the east or south ; some of 
 the landscultivated, others wild and 
 woody ; not far from the sea or a 
 navigable river, for the easier ex- 
 portation of the produce of the 
 farm, and the importation of ne- 
 cessaries. The champaign lying 
 below the house should be dis- 
 posed into grounds for pasture and 
 tillage, osiers and reeds ; some of 
 the hills should be naked and 
 
 534 
 
VIL 
 
 VILLAS OF THE ANCIENTS. 
 
 VIL 
 
 without trees, that they may serve 
 best only for corn, which grows in 
 a soil moderately dry and rich, bet- 
 ter than in steep grounds; where- 
 fore the upper corn-fields should 
 have as little declivity as possible, 
 and ought to resemble those in the 
 plain : from thence, the other hills 
 shouldbe laid outinto olive grounds 
 and vineyards, and produce trees 
 necessary to make props for those 
 fruits, and, if occasion should re- 
 quire building, to afford timber 
 and stone, and also pasture for 
 cattle. Moreover, constant rivu- 
 lets of water should descend from 
 thence upon the meadows, gardens, 
 and osier-grounds, and also serve 
 for the convenience of the cattle 
 that graze in the fields and thickets, 
 but such a situation is not easily to 
 be met with ; that which enjoys 
 most of these advantages is cer- 
 tainly most valuable ; that which 
 has them in a moderate degree, is 
 not despicable. The natural good 
 qualities of a situation mentioned 
 by Palladio are, a salutary air, 
 plenty of wholesome water, a 
 fruitful soil, and a commodious 
 place : we may hence conclude that 
 those places are healthy that are 
 not located in deep valleys, or 
 subject to thick clouds, where the 
 inhabitants are of a fresh com- 
 plexion, have clear heads, good 
 sight, quick hearing, and a free dis- 
 tinct speech ; for by these things is 
 the goodness of the air distinguish- 
 ed; and the contrary appearance 
 proclaimsthat climate to be noxious. 
 The unwholesomeness of water 
 may be thus discovered : in the 
 first place, it must not be conveyed 
 from the ditches or fens, or rise 
 from minerals, but be very trans- 
 parent, not tainted either in taste 
 or smell, without settlement, in 
 winter warm, in summer cold ; but 
 because nature often conceals a 
 more lurking mischief, in these 
 outward appearances, we may 
 judge whether water is good by 
 the health of the inhabitants : if 
 
 their cheeks are clear, their heads 
 sound, and little or no decay in 
 their lungs and breasts ; for gene- 
 rally where the distempers in the 
 upper part of the body are trans- 
 mitted down to the lower, as from 
 the head to the lungs or stomach, 
 there the air is infectious : besides, 
 if the belly, bowels, sides, or veins, 
 are not afflicted with aches 01 tu- 
 mours, and there is no ulcer in the 
 bladder; if these or the like are 
 apparently in the major part of the 
 inhabitants, there is no cause to 
 suspect the unwholesomeness of 
 the air and water. The fatal con- 
 sequences proceeding from bad air, 
 Varro tells us, are in some measure 
 to be alleviated, if not prevented, by 
 the skill of the architect. His 
 words are: That land which is 
 most wholesome is most profitable, 
 because there is a certain crop ; 
 whereas, on the contrary, in an un- 
 healthy country, notwithstanding 
 the ground is fertile, yet sickness 
 will not allow the husbandman to 
 reap the fruits of his labour ; for 
 where one exposes his life to cer- 
 tain dangers, for uncertain advan- 
 tages, not only the crop, but the 
 life of the inhabitant, is precarious; 
 wherefore, if it is not wholesome, 
 the tillage is nothing else but the 
 hazard of the owner's life and his 
 family : but this inconvenience is 
 remedied by knowledge, for health, 
 which proceeds from the air and 
 soil, is not in our disposal, but 
 under the guidance of nature ; yet, 
 nevertheless, it is as much in our 
 power to make that burden easy 
 by our own care; for, if upon 
 account of the land or water, or 
 some unsavoury smell, which makes 
 an irruption in some part of it, 
 the farm is made unwholesome, or 
 upon account of the climate, or a 
 bad wind that blows, the ground is 
 heated, these inconveniences may 
 be remedied by the skill and ex- 
 pense of the owner, which makes 
 it of the last concernment where 
 the villas are placed, how large 
 
VIL 
 
 VILf AS, ROMAN. 
 
 VIL 
 
 they are, and to what quarters their 
 porticoes, gates, and windows are 
 tnrned. Did not Hippocrates the 
 physician, in the time of a great 
 plague, preserve not only his own 
 farm, but many towns, by his skill? 
 When Varro and his army and his 
 fleet lay at Corcyra, and every 
 house was filled with sick persons 
 and dead bodies, by his care in 
 making new windows to the north- 
 east, and obstructing the infection 
 by altering the position of the doors, 
 he preserved his companions and 
 family in good health. As a house 
 should be built in a wholesome 
 country, so it should be in the most 
 wholesome part of a country ; for 
 an open air and at the same time 
 infected, causes many distempers." 
 Villas (Roman). The term villa was 
 applied to a cluster of buildings in 
 the country for the accommodation 
 of the family of a wealthy Roman 
 citizen. Very extensive villas were 
 divided into three parts, the Ur- 
 bana, the Rustica, and the Fruc- 
 tuaria. The first contained the 
 eating-room, bed-chambers, baths, 
 covered porticoes, walks, and ter- 
 races. The villa rustica was the 
 division for the servants, stables, 
 etc. ; and the fructuaria for wine, 
 oil, and the produce of the farm. 
 Although the Roman villas were 
 the boast and delight of poets and 
 philosophers whose works have for- 
 tunately reached us, yet no de- 
 scription has been conveyed of their 
 external architecture. From the 
 magnificent style of public build- 
 ings at Rome, moderns were led to 
 suppose that the villa architecture 
 bore some analogy in splendour of 
 outward appearance ; but from in- 
 spection of their remains, and from 
 the late disintermentof one on the 
 outside of the walls of Pompeii, 
 little doubt now remains on the 
 subject. It is true that the exten- 
 sive remains of Adrian's villa, and 
 that of Maecenas, covered ground 
 equal almost to a small town, but 
 no regular plan of architectural 
 
 536 
 
 elevation can be traced with all the 
 ingenuity of even a Roman anti- 
 quary. The Pompeian is certainly 
 the most complete example of an 
 ordinary-sized Roman villa : situ- 
 ated on a sloping bank, the front 
 entrance opened, as it were, into 
 the first floor, below which, on the 
 garden side, into which the house 
 looks (for the door is the only 
 aperture on the road side), was a 
 ground floor, with extensive ar- 
 cades and open rooms, all facing 
 the garden ; and above were the 
 principal rooms. It was spacious, 
 and near the entrance was a bath 
 with all the necessary appendages ; 
 in the rear the best rooms opened 
 upon a terrace, running the whole 
 width of the house, and overlook- 
 ing a garden about 30 yards square, 
 surrounded by a covered walk or 
 portico continued under the terrace. 
 The lower apartments under the 
 arcade were paved with mosaic, 
 coved and beautifully painted. One 
 of the rooms had large glazed bow 
 windows ; the glass was thick, of 
 a green colour, and set in lead like 
 a modern casement. The walls 
 and ceilings of the villa were orna- 
 mented with paintings of elegant 
 design, all of which had relation 
 to the uses of the respective apart- 
 ments. In the middle of the gar- 
 den was a reservoir of water, sur- 
 rounded by columns. The cellars 
 extended under the whole of the 
 house and the arcades. 
 
 Pliny tells us that the size of 
 the villa urbana, and its number 
 of parts, were determined by the 
 pleasure or quality of the master, 
 but those parts belonging to agri- 
 culture, by the bulk of the farm 
 and the number of cattle. The ser- 
 vants that in most great men's 
 houses were more immediately for 
 the master's use, and may be said to 
 have belonged to the villa urbana, 
 were the atrienses, which included 
 all those we call livery servants, and 
 those belonging to the bed-cham- 
 ber ; and the topiarii, which were 
 
VILLAS, ITALIAN. 
 
 VIS 
 
 gardeners belonging to the pleasure- 
 garden; with comedians, musicians, 
 and the notaries or secretaries. The 
 principal person over the other 
 parts of the villa was the procurator 
 or hailiff; then the villicus, or hus- 
 bandman, who had under his care 
 the tillage of the land, and the 
 disposal of the produce of the earth 
 about the villa ; next was the villica, 
 or house-keeper, to whose care 
 everything within doors belonged, 
 and who hadimmediatelyunder her 
 command the women servants that 
 were employed in those affairs, but 
 particularly those belonging to the 
 feeding and clothing of the house- 
 hold. The master of the cattle 
 may take the next place, and under 
 his command were all the herds- 
 men, shepherds, goatherds, swine- 
 herds, and grooms. The care of 
 all those fowls that were within the 
 bounds of the villa was committed 
 to the poulterer. In great villas 
 it was thought necessary to keep 
 within the family useful mechanics, 
 as smiths, carpenters, etc. The 
 cattle within the villa were horses 
 and mules, etc. ; and to make pro- 
 vision for the several persons and 
 animals, and also for corn and 
 the necessary offices of the house, 
 was the architect's care ; and the 
 disposition of each part was go- 
 verned by rules that may be col- 
 lected from Cato, Vitruvius, Va:-ro, 
 Columella, and Palladius. 
 
 Of the Greek villas, no descrip- 
 tion has been transmitted to us ; 
 in villa gardening, however, con- 
 siderable progress at that time was 
 made, borrowed probably from 
 Asia Minor : myrtles and roses 
 adorned them ; the box and lime 
 tree were planted for topary works ; 
 and Theophrastus tells us, that 
 flowers and fruits were cultivated 
 in the winter ; and the violet more 
 particularly was in profusion in the 
 market of Athens while snow was 
 on the ground. 
 
 Villas (Italian). The description of 
 an Italian villa built in the time of 
 
 Michael Angelo, Raphael, Julio 
 Romano, Domenichino, Paul Ve- 
 ronese, and Pietro da Cortona, de- 
 serves the notice of architects. "The 
 palace of Caprarola is situated on 
 the summit of Mount Camino, near 
 Viterbo : below is the village of 
 the same name, of which the prin- 
 cipal street runs in a direct line 
 down the descent from the front 
 of the building, but with a sufficient 
 space between them. A double 
 stair, partly direct, partly curved, 
 with terraced landing-places deco- 
 rated with balustrades, leads to the 
 palace. Entrances under the ter- 
 races of the stairs conduct to the 
 underground parts of the building. 
 The form of the palace is a p*eu- 
 tagon flanked by five bastions, sur- 
 rounded by a sunk area. Hence 
 there is a mixture of civil and 
 military architecture that has a 
 good effect. The palace is built 
 in two orders of architecture ; the 
 one, Ionic,with semicircular-headed 
 windows; the upper Corinthian, 
 comprehending both the first floor 
 and the mezzanine above. Within 
 the pentagonal figure is included a 
 circle, comprehending the court, j 
 the porticoes, the offices, and stairs. \ 
 The decorations of the whole and j 
 the parts are executed with much i 
 skill. Although the entire edifice 
 is not great, yet the parts are on a 
 great scale, apparently." 
 
 Virtuoso, a man skilled in antique j 
 or natural curiosities, studious of 
 painting, statuary, or architecture. 
 
 Vis absoluta, absolute force. 
 
 Vise, a spiral staircase, the steps of 
 which wind round a perpendicular 
 shaft or pillar, called the newel. 
 
 Vis inertia, the propensity of nature 
 to remain in its actual condition, 
 whether of motion or rest, and to 
 resist change. 
 
 Vis insita, the power or innate force 
 essentially residing in any body, and 
 by which it endeavours to preserve 
 its present state, whatever that 
 be. 
 
 Viscount, in law, signifies as much as 
 
VIS 
 
 VOLUTE. 
 
 AVAL 
 
 sheriff: in heraldry, it signifies a 
 degree of nobility next to an earl. 
 
 Vis viva (work). The vis viva of 
 a body is its mass multiplied by 
 the square of its velocity : work, 
 or dynamical effect,supposes. a body 
 moved, and a resistance overcome ; 
 and either of these, without the 
 other, is insufficient to constitute 
 work. The work produced by a 
 pressure moving a body through a 
 certain space is defined to be the 
 product arising from multiplying 
 the pressure by the space through 
 which this pressure acts. 
 
 Vitreous, glassy ; consisting of or re- 
 sembling glass. 
 
 Vitrification, the act of changing into 
 glass. 
 
 Vitriol, oil of, sulphuric acid. 
 
 Vitruvian Scroll, a peculiar pattern, 
 consisting of convolved undula- 
 tions, used in classical architecture. 
 
 Viz. to wit, that is ; a contraction of 
 videlicet. 
 
 Voider, in heraldry, a gentlewoman's 
 armory, consisting of an arch line, 
 moderately bowing from the corner 
 of the chief toward the nombril 
 or centre of an escutcheon. 
 
 WAGGONS, vehicles for the convey- 
 ance of merchandise, etc., varying 
 in form according to their use, and 
 dating in their origin from the re- 
 motest antiquity : " Joseph gave 
 them waggons, according to the 
 commandment of Pharaoh, and gave 
 them provision for the way." 
 
 Waggon-boiler, a low-pressure boiler, 
 having the form of a waggon, with 
 arched top and. incnrvated sides. 
 
 Wainscot, a name giren to boards em- 
 ployed to line the internal walls 
 of an apartment, so called from 
 foreign species of oak named wain- 
 scot being first used for such a 
 purpose, Wainscoting, as it is 
 called, both of Flemish and Eng- 
 lish oak, was commonly used for 
 interior linings in Tudor, Eliza- 
 bethan, and Stuart times. 
 
 538 
 
 Voiding, a term in heraldry, signify- 
 ing exemption of some part of the 
 inward substance of things voida- 
 ble, by reason whereof the field is 
 transparent through the charge. 
 
 Volant, in heraldry. When a bird is 
 drawn flying, or having the wings 
 spread out, it is said to be volant. 
 
 Volute. The characteristic ornaments 
 and indicial marks of the Ionic 
 capital formed by circumvolving 
 spiral mouldings are termed vo- 
 lutes. The small circle in which 
 the spiral or springs terminate is 
 called the eye of the volute. The 
 introduction of volutes is said by 
 Vitruvius to have arisen from an 
 imitation of the mode in which 
 women were formerly accustomed 
 to ornament their hair; but they 
 are thought, with greater proba- 
 bility, to have represented the 
 horns of the Ammonian Jupiter. 
 
 Voussoirs, in architecture, vault- 
 stones, or those that immediately 
 form the arch of a bridge, vault, 
 etc., and are always cut more or 
 less in the shape of a truncated 
 pyramid. 
 
 Vuyh, in mining, a cavity. 
 
 Waist, in a ship, the uppermost part 
 of the top-side. 
 
 Wake, in navigation, denotes the 
 print or track of a ship on the 
 surface of the waters. Two dis- 
 tinct objects seen at sea are said to 
 be in the wake of each other when 
 the view of the furthest is inter- 
 rupted by the nearest. 
 
 Wales, in ship-building, are an as- 
 semblage of strong planks extend- 
 ing along a ship's side, serving to 
 reinforce the decks and form the 
 curves of the vessel. 
 
 Wall-plate, a piece of timber placed 
 along the top of a wall, to receive 
 the ends of the roof timbers, or so 
 placed on a wall as to receive the 
 joists of a floor. 
 
 Walnut wood. The royal or com- 
 mon walnut is a native of Persia 
 
WATER. 
 
 WAT 
 
 and the north of China : it was 
 formerly much used in England 
 before the introduction of ma- 
 hogany. The heart wood is of a 
 greyish brown, with black-brown 
 pores, and often much veined with 
 darker shades of the same colour. 
 Some of the handsome veneers are 
 now used for furniture, frames of 
 machines, gun-stocks, etc. 
 Tardrobe, a place where the gar- 
 ments of kings or great persons 
 used to be kept ; and he that 
 keeps the inventory of all things 
 belonging to the king's wardrobe 
 is called Clerk of the King's 
 Wardrobe. 
 
 Wards, and Liveries, a certain court 
 erected in the time of Henry VIII. 
 
 Warp, in navigation, to change the 
 situation of a ship in harbour, 
 etc., by means of ropes or warps 
 attached to buoys, posts, rings, 
 trees, etc. 
 
 Washing, in painting, to lay a colour, 
 such as Indian ink or bistre, over 
 a pencil or crayon drawing, to 
 render it more natural, and add to 
 the shadow of prominences, aper- 
 tures, etc. 
 
 Wassail, a term which is said to have 
 had its origin at the meeting of Vor- 
 tigern and Rowena, the daughter 
 of Hengist. Geoffrey of Monmouth 
 states, that the lady knelt before 
 the king, and presenting him with 
 a cup of wine said, ' Waes-hael,' 
 which in Saxon means ' Health be 
 to you.' Vortigern, as he was in- 
 structed, replied, ' Drinc-hael,' i. e. 
 1 drink the health :' Rowena drank, 
 upon which Vortigern took the cup 
 and pledged her. Hence the term 
 and custom. 
 
 Waste steam-pipe, in steam-engines, 
 the pipe leading from the safety 
 valve to the atmosphere. 
 
 Waste water-pipe, in steam engines, 
 the pipe for carrying off the surplus 
 water from the hot well. 
 
 Water is the most abundant and im- 
 portant fluid in nature ; it is proved 
 to be composed, by weight, of 8 
 parts of oxygen and 1 part of 
 
 hydrogen, and is resolvable into 
 both these gases by voltaic action, 
 and by intensely ignited platinum : 
 other heated metals combine with 
 its oxygen, and liberate the other 
 gas. When hydrogen and oxygen 
 are mixed in the proportion given, 
 and ignited, they unite with explo- 
 sion, and water alone is produced. 
 The purest water in nature is that 
 which descends from the atmo- 
 sphere ; that of springs, rivers, and 
 the sea being more or less charged 
 with mineral matter. When the 
 foreign substance is not volatile, 
 the water is easily separable by 
 distillation in the form of a pure 
 vapour or steam, while the fixed 
 substance remains. In nature, the 
 solar heat produces this effect on a 
 vast scale, evaporating enormous 
 quantities of water into the atmo- 
 sphere, whence, by cooling to va- 
 rious degrees, it falls again in the 
 form of rain, hail, or snow : this, 
 in its passage through different 
 strata towards its lowest level, dis- 
 solves any soluble matters which 
 it may encounter, of which salt is 
 the most conspicuous, conveying 
 them ultimately into the ocean. 
 This process, operating for ages, is 
 fully sufficient to account for the 
 prevalence of so soluble a mineral 
 as common salt in sea-water, and the 
 comparative purity of that of rivers. 
 When water runs through beds 
 of chalk or selenite, it acquires both 
 an acid and alkaline quality in a 
 small degree. The acid is discovered 
 by a few drops of solution of oil of 
 tartar : this alkali will seize the 
 acid, and descend with it in a cloud 
 to the bottom of the glass, where, 
 if permitted to stand a sufficient 
 period, it will concrete into a neu- 
 tral salt. The alkaline part is 
 discoverable by a few drops of 
 the solution of oxalic acid. This 
 acid has so strong an affinity to 
 calcareous earth, that the smallest 
 quantity in water is detected by 
 it. There are numerous tests which 
 discover acid and alkali in water ; 
 
WAT 
 
 WATER. 
 
 WAI 
 
 as the syrup of violets, tincture of 
 turnsole, ash-bark, logwood, etc. 
 Strictly, philosophically speaking, 
 sea-water is not salt, because if a 
 given quantity is put into a glass 
 retort, by sand heat from material 
 fire it will pass over perfectly fresh, 
 and the marine salt it contained 
 will be left behind. Snow and 
 rain water, when collected at a 
 distance from smoky towns or 
 cities, if collected and kept in a 
 stagnated stage, go repeatedly into 
 a state of fermentation, and some- 
 times become putrid, by the ex- 
 traneous matters they receive in 
 passing through the loww atmo- 
 sphere, previous to their reaching 
 the earth. If the specific gravity 
 of water is considered at 1000 
 ounces the cubic foot, common air 
 will be 1, fine gold will be 2^0' 
 and pure platina adnnyJ or if a 
 datum is taken of 1 for water, gold 
 will be 20, and refined platinum 22. 
 Water is incompressible, as expe- 
 riment proves. It has been put 
 into a gold globe, and great power 
 applied in vain to press it into 
 a smaller compass ; it passed off 
 by oozing or sweating through the 
 pores of gold. It will rise in some 
 cases above its own level. In a 
 small degree, by capillary attrac- 
 tion. If a piece of dry loaf-sugar 
 or sponge is put into a shallow 
 vessel of water, and have part of it 
 unimmerged, the fluid will be seen 
 to ascend above its level. Water will 
 also ascend to the height of 32 or 
 33 feet above its level in a vacuum, 
 as in pumps, by the pressure of the 
 atmosphere, which varies more or 
 less according to its density, that 
 is, calculating on the pressure of 
 the atmosphere, at the height of 
 15 miles. The pressure of water 
 on the base of the vessel in which 
 it is contained is as the base and 
 perpendicular altitude, whatever be 
 the figure of the vessel that con- 
 tains it. A body immersed in 
 water loses as much weight as an 
 equal bulk of the water weighs, 
 
 and the water gains the same 
 weight. Thus, if the body be of 
 equal density with the water, it 
 loses all its weight, and so requires 
 no force but the water to sustain 
 it : if it be heavier, its weight in 
 the water will be only the differ 
 ence between its own weight and 
 the weight of the same bulk of 
 water, and it requires a force to 
 sustain it just equal to that differ- 
 ence ; but if it be lighter, it re- 
 quires a force equal to the same 
 difference of weight to keep it from 
 rising up in the fluid. 
 
 Water of great rivers raay cer- 
 tainly be deemed the most pure 
 and wholesome for all culinary 
 and domestic concerns, independ- 
 ent of its superior fertilizing powers 
 when used for the purpose of agri- 
 culture or the growth of plants; 
 and when thrown into reservoirs, 
 and cleared of its sediment, it be- 
 comes clear and equally transparent 
 with the brightest water proceed- 
 ing from the hardest rock ; for, 
 previous to its being thus deposited, 
 while swiftly gliding within its 
 banks, it deposits large portions of 
 its bituminous, calcareous, argil- 
 laceous, and chalybeate qualities. 
 
 Water is a conductor of atmo- 
 spheric air, as well as sound. 
 In Ralph Dodd's ' Civil Engineer ' 
 an accident is mentioned, by which 
 one of his workmen was buried, 
 by the falling of 40 feet of a shaft, 
 the bottom of which approached 
 to a sand highly charged with 
 water. He* remained from Friday 
 evening till Tuesday morning. The 
 workmen were this considerable 
 time before they came to him, 
 conversing together and excavating 
 over his head, which considerably 
 increased his hope of being re- 
 leased from his horrid captivity : 
 for he became aware of their 
 endeavours for his release as soon 
 as the workmen had entered the 
 sandy stratum, through which the 
 water filtered downward, a strong 
 evidence of its conveying sound, 
 
 540 
 
WAT 
 
 WATER-COLOUR PAINTING. 
 
 WAT 
 
 as well as atmospheric air, or, 
 doubtless, lie could not have ex- 
 isted. 
 
 Day-springs, either lying near 
 the surface of the earth, or finding 
 fresh passages thither, break forth 
 into open air on their own account ; 
 while those of a deeper nature are 
 sunk down so low as to require 
 hydraulic machinery to bring them 
 up again. Next, they are called 
 top-springs, inasmuch as they ap- 
 pear either above the rock which 
 severs the soil from the mine, or 
 underneath it. Top-springs differ 
 from deep or other springs, in that 
 they stagnate between the super- 
 ficies of the earth and the surface 
 of the parts confining them, till 
 they are opened by the miner ; 
 and those springs that can be let 
 oft' by drifts, headings, soughs, and 
 trenches, are distinguished from 
 those from a great depth, the drain- 
 ing of which by such means is alto- 
 gether impracticable or absolutely 
 impossible. In the search after 
 the original source of those cur- 
 rents of water which issue out 
 of the earth, and are commonly 
 called day-springs, the first con- 
 sideration that arises is, that their 
 natural course, as consisting in 
 motion, is merely local, and caused 
 by the propension of their own 
 weight, still drawing them down- 
 ward, towards the centre o^ the 
 earth : their course must always 
 be upon a constant descent from a 
 higher situation to a lower, and 
 so must proceed originally from 
 rain, distilled from the clouds. 
 And if it happen, that at their 
 emersion out of the earth, their 
 spring rises upwards, it is caused 
 by the curvity of their passage, 
 that (siphon-like) points the way ; 
 while the preponderance of the 
 water contained in its other arm, 
 descending from a greater height, 
 forces it to rise contrary to its 
 natural inclination. 
 
 The specific gravity of rain-water 
 is 1000; weight of a cubic foot 
 
 62^ Ibs. ; weight of a column, one 
 inch square and a foot in height, 
 0-434 Ibs.; of an ale gallon 10'2 
 Ibs. : expands T X T of its bulk in 
 freezing, and ggVs for every degree 
 of heat: boils at 212 under the 
 ordinary pressure of the atmo- 
 sphere : maximum density 39 P 38 
 of Fahr. The specific gravity of 
 sea-water is 11-0271. 
 
 Water-colour painting is the art of 
 making a picture with colours 
 ground up with various kinds of 
 aqueous gums or sizes, then called 
 transparent colours. These draw- 
 ings are executed on various kinds 
 of paper, and are generally termed 
 tinted drawings. The following 
 are the most permanent colours, 
 and therefore most valuable to the 
 water-colour painter : blues ul- 
 tramarine, French ultramarine, co- 
 balt, indigo, and smalt : reds In- 
 dian red, light red, Venetian red, 
 scarlet, vermilion, carmine, pink 
 madder, rose madder, purple lake, 
 and red orpiment: yellows cad- 
 mium yellow, gamboge, yellow 
 ochre, Indian yellow, Mars yellow, 
 lemon yellow, Roman ochre, brown 
 ochre, Mars orange, raw sienna, 
 Italian pink, gallstone, and king's 
 yellow : purples purple madder, 
 Indian purple, and burnt carmine : 
 browns burnt sienna, brown pink, 
 burnt umber, Vandyke brown, se- 
 pia, Mars brown, Cologne earth, 
 bistre, and madder brown : greens 
 emerald green, olive green, and 
 green oxide of chromium : blacks 
 ivory black, blue black, neutral 
 tint, and British ink : whites ox- 
 ide of zinc or Chinese white, and 
 sulphate of barytes or constant 
 white. 
 
 Water-crane, an apparatus for sup- 
 plying water from an elevated tank 
 to the tender of a locomotive engine. 
 
 Watering the streets of Paris (the 
 contract for}. The contractor for 
 this service receives 105, 000 francs 
 per annum, or 4200 sterling. 
 It lasts from March 15th to Octo- 
 ber 15th. 
 
 2 A 
 
WAT 
 
 WATI?R SUPPLY. 
 
 WAT 
 
 He is bound to hold at the dis- j 
 posal of the engineers who are j 
 charged with the direction of the j 
 roads, twenty-five carts during the i 
 first month of the season ; during i 
 the second, the number is fixed at ! 
 fifty-five ; during the remainder at i 
 ninety, with fifteen others in re- j 
 serve. These carts can only be j 
 used for the service of the town ; I 
 and they are repainted every year, i 
 They contain 1 metre cube, or 1 j 
 ton 'each, and are drawn by one 
 horse. They have a double dis- 
 charge hose, at the front and at 
 the back. At half-play they water 
 1000 metres superficial. At full 
 play they water 700 metres super- 
 ficial. In the first case, they are 
 emptied in 10 minutes; in the 
 second, in 6 minutes. Each cart 
 costs 800 francs, or 32 ; of which 
 200 francs, or 8, are for the ma- 
 chinery necessary for the distribu- 
 tion of the water. 
 
 The Avenue de Neuilly in the 
 Champs Elysees forms a special 
 service, on account of the immense 
 number of carriages which traverse 
 it. The total surface is 32,000 ' 
 metres superficial, or nearly 8 acres 
 English (7-976 a). The cost per | 
 day in the summer months is as 
 follows : 
 
 2 water-carts, horse and 
 driver included, each 
 at ll-10f. = . . . 22-20 
 84-OO m cube water (a 
 metre cube = 1 ton) 
 at 0-137 f . = . . . 11-50 
 Turncock (portion of his 
 
 time) 2-00 
 
 Total 35-70 
 
 or 0-001116 f. per metre super- 
 ficial. 
 
 It has been found that the streets 
 of Paris require to be watered 135 
 days on the average ; the numbers 
 are between 107 in the wettest sea- 
 son, and 147 in the driest. On 
 the above average of 135, 100 days 
 require a double watering. The 
 quantity consumed is about 1 litre 
 
 542 
 
 (1-760773 pints English) per metre 
 superficial; H litre, when the 
 roads are so very dry as to require 
 a more abundant watering ; and 
 1-60 litre (or 2*82 pints English) 
 in the Avenue de Neuilly. The 
 water-columns are spaced so as to 
 avoid any useless movements of the 
 carts ; in fact, in such a manner as 
 to allow of their being emptied be- 
 tween one column and the other. 
 The usual distance is 500 metres 
 (about 550 yards) . 
 Water-mil, in navigation, a small 
 sail spread occasionally under the 
 lower studding-sail or driving- 
 boom, during a fair wind and 
 smooth sea. 
 
 Water-spout, a strongly agitated mass 
 of air, which moves over the sur- 
 face of the earth, and revolves on 
 an axis, of which one extremity is 
 on the earth and the other in a j 
 cloud. From this cloud a continu- 
 ation proceeds downwards, which 
 forms the upper portion of the wa- 
 ter-spout; while the lower portion, 
 besides air, consists sometimes of 
 water, sometimes of solid portions, 
 according as the \vater-spout passes 
 over land or over water. Some 
 have separated water-spouts over 
 the land and over the water from 
 each other; but this creates confu- 
 sion, for water-spouts have been 
 observed which were formed over 
 water, and advance over land ; and 
 vice versa, we have accounts of 
 water-spouts which were formed 
 over land, and afterwards sus- 
 pended over the surface of water. 
 Water supply for towns. A plentiful 
 supply of water fitted for drinking, 
 culinary, and detergent purposes, 
 is so essentially an article of every^ 
 day use, that in all ages, wher- 
 ever a quantity of human beings 
 have been congregated together, 
 contrivances have necessarily been 
 resorted to, to procure a supply : 
 in some situations wells are sunk to 
 a considerable depth, from which 
 water is lifted by means of buckets, 
 pumps, or like contrivances ; in 
 
WAT 
 
 WATER SUPPLY FOR TOWNS. 
 
 WAT 
 
 others, the rain- water falling on the 
 roofs of houses is caught and hus- 
 banded in suitable receptacles, or, 
 as was much practised in ancient 
 times, where large populations ex- 
 isted, rivers are diverted for their 
 use from their natural channels, 
 and conducted over valleys and 
 through mountains in artificial 
 courses having a small but con- 
 tinuous decline. 
 
 Much has been written and said 
 of the plentiful supply of water 
 brought into ancient Rome and 
 towns in Italy, Spain, and other 
 places, by means of aqueducts ; 
 but the streams supplying these 
 aqueducts would yield but little 
 water in the dry summer and 
 autumn weather, as is proved from 
 the number of sources from which 
 water was frequently brought to a 
 town. Ancient Rome, according to 
 some writers, was supplied from 
 no less than twenty aqueducts, all 
 deriving their water from different 
 sources. These aqueducts were 
 built at separate times, and they 
 were doubtless made to supply a 
 pressing want ; for although in wet 
 and moderate seasons, probably 
 one-third this number would have 
 yielded a supply adequate to the 
 .demand, it is much to be doubted 
 if this was the case in seasons of 
 drought ; especially as the ancients 
 made no provisions by means of 
 impounding reservoirs to store a 
 supply from wet to dry seasons. 
 
 In ancient times, water was 
 brought to a town from rivers or 
 springs more elevated than the town 
 itself, and was distributed through 
 fountains to the inhabitants, who 
 fetched it in vessels to their houses. 
 
 In modern times, excessive floods 
 are frequently stored in large re- 
 servoirs, to yield a supply to our 
 towns in seasons of drought; or 
 water from a neighbouring river, 
 or from deep wells sunk in a sub- 
 terranean reservoir, or water-bear- 
 ing stratum situated below the 
 level of a town, is frequently lifted 
 
 by means of pumps, worked by 
 steam or water power, through a 
 line of cast-iron pipes into a reser- 
 voir of sufficient altitude to admit 
 of its being conducted from thence 
 through other pipes to the highest 
 house in a town ; and it is no un- 
 common thing at the present time 
 to lift water from 200 to 300 feet 
 in elevation for this purpose. 
 
 But the greatest improvement 
 lately made for supplying towns 
 with water consists in the arrange- 
 ments for conveying it, when raised 
 to a sufficient altitude, in cast iron 
 or lead pipes, into the house of 
 every inhabitant, even to the upper 
 story, so that this necessary article 
 can always be secured "by the 
 turning of a cock : it is also dis- 
 tributed in the same manner for 
 watering roads, and for use in case 
 of fire ; and it is principally in the 
 excellent system of distribution, 
 which perfection in the art of 
 making the pipes has induced, that 
 renders modern water-works supe- 
 rior to those of ancient times. 
 
 It is of the utmost importance 
 to every house to be supplied plen- 
 tifully with wholesome soft-wfter, 
 and there are now few places in 
 which this cannot be accomplished 
 at a cheap rate. 
 
 The modern cost of supplying 
 water to a large town may now 
 be taken at a low estimate per 
 head of the population supplied, 
 according to the facilities or diffi- 
 culties that exist for procuring and 
 distributing the supply : as a gene- 
 ral rule, river-water, when unpol- 
 luted with the drainage of a town, 
 or the rain-water flowing down the 
 sides of steep hills of a retentive 
 character, when properly filtered, 
 is superior in quality, and better 
 adapted for most domestic uses 
 than the brightest spring water, 
 owing to its freedom from saline 
 matter, which is usually denomi- 
 nated softness. 
 
 All rain and surface water should, 
 however, be carefully filtered be- 
 
 543 
 
 2 A 2 
 
WAT 
 
 WATEft-WHEEL. 
 
 WAT 
 
 fore it is applied for domestic uses, 
 not only to free it from earthy me- 
 chanical impurities, but to rid it of 
 organic matter, which in summer- 
 time and warm weather is always 
 mixed with such water in a greater 
 or less degree, and the presence of 
 which renders it unwholesome for 
 drinking or culinary uses. It is 
 principally owing to its freedom 
 from organic matter that spring- 
 water, though usually hard, is pre- 
 ferred to river-water as a beverage. 
 London is supplied with water 
 chiefly by eight companies, the 
 New River, East London, West 
 Middlesex, Chelsea, Grand Junc- 
 tion, Lambeth,Vauxhall, and South- 
 wark. 
 
 Water-ways, in ship-building, the 
 planks of the deck which are close 
 to the timbers. 
 
 Water-wheel, a wheel turned on its 
 axis by the weight of water falling 
 upon its circumference, and thus 
 adapted as a machine for deriving 
 power wherever a fall of water can 
 be commanded. For this purpose 
 the wheel is erected in a vertical 
 position upon a horizontal shaft 
 or axis, and the periphery of the 
 wheel is so formed that the great- 
 est possible effect shall be received 
 from the weight or gravity of the 
 falling water. To obtain this ef- 
 fect, the rim of the wheel is pro- 
 vided with small troughs or buckets 
 in which the water is received, and 
 its weight made active in carrying 
 down that part of the periphery on 
 which the loaded buckets are situ- 
 ated. As they approach the lowest 
 position, they become emptied, and 
 are thus prepared to be carried up- 
 ward during the revolution of the 
 wheel, while the descending buck- 
 ets are successively receiving their 
 supply from the fall of water. 
 Water-wheels are commonly dis- 
 tinguished according to the height 
 of the fall in comparison with the 
 diameter of the wheel, and the po- 
 sition at which the water acts upon 
 the buckets. Thus if the depth of 
 
 544 
 
 fall equals the diameter of the 
 wheel, (besides allowing a little de- 
 clivity below the wheel, for the 
 ready escape of the back-water,) so 
 that the water falls on the highest 
 point of its periphery, the wheel is 
 said to be an ' overshot ' water- 
 wheel. If the depth of fall is less, 
 so that the water falls upon the 
 wheel, only a little above the level 
 of its centre, the wheel is called a 
 41 breast " wheel. And if the depth 
 of fall is so little that the water 
 acts by impulse only against the 
 lower parts of the wheel, it is called 
 an 'undershot' water-wheel. Water- 
 wheels are now made in the most 
 improved manner of iron, the arms 
 being of wrought iron, the centres 
 of cast iron, and the buckets of 
 plate iron. A water-wheel thus 
 constructed consists of a centre 
 boss, and shaft, arms, buckets, and 
 shrouding, the latter being the 
 term applied to the rims of the 
 wheel, between which the buckets 
 are enclosed. In order to derive 
 the greatest working effect from a 
 given fall of water, the principal 
 object is to shape the buckets so 
 that they shall retain the water 
 during the longest possible period. 
 One great difficulty experienced in 
 seeking this object has been the 
 opposition exerted by the air to 
 the admission of the water into 
 the buckets; and, to counteract this 
 evil, several methods have been 
 devised. The only efficient remedy 
 yet introduced is that invented by 
 Mr. Fairbairn, and which he de- 
 nominates the ' Ventilating Water- 
 wheel,' the general object of which 
 is to prevent the condensation of 
 the air, and to permit its escape 
 during the filling of the bucket 
 with w ater, as also its re-admission 
 during the discharge of the water 
 into the lower mill-race. Several 
 wheels erected and fitted upon this 
 principle have proved entirely suc- 
 cessful in realizing a maximum use- 
 ful effect from a given fall of water. 
 All these wheels are formed with 
 
WAT 
 
 WATER-WHEEL. 
 
 WAT 
 
 wrought iron arms radiating from 
 cast-iron centres to the periphery, 
 and so disposed that the entire 
 structure is in a state of tension, 
 and the motion of the wheel 
 being communicated from internal 
 toothed wheels fixed to the shroud- 
 ing. As applied to common breast- 
 wheels adapted for falls not ex- 
 ceeding 18 or 20 feet, these venti- 
 lating buckets effect so great an 
 improvement, that if the wheel is 
 plunged in back-water to the depth 
 of 5 or 6 feet, its uniform speed is 
 not impended. In these wheels the 
 sole of the buckets is close, and the 
 tail end of them being turned up 
 at a distance of 2 inches from the 
 back of the sole-plate, and running 
 parallel with it, terminate within 
 about 2 inches of the bend of the 
 bucket, immediately above it. The 
 water in entering the bucket drives 
 the air out through the aperture 
 into the space behind, and thence 
 into the bucket above, and so on 
 in succession. The converse oc- 
 curs when the buckets are emptied, 
 as the air is enabled to enter as 
 fast as the wheel arrives at such a 
 position as to permit the water to 
 escape. (For a more copious de- 
 scription, see Water-wheels with 
 ventilating buckets, by Fairbairn.) 
 
 There are many cases in which 
 it is of importance to know the 
 proportion of power necessary to 
 give diiferent degrees of velocity 
 to a mill ; but as the construction 
 of mills and the purposes they 
 serve are various, it is perhaps im- 
 possible to find any law of univer- 
 sal application. Mr. Banks, in 
 his ' Treatise on Mills,' has drawn 
 a conclusion which he appears to 
 consider invariable, namely, that 
 " when a wheel acts by gravity, its 
 velocity will be as the cube root 
 of the quantity of water it re- 
 ceives." 
 
 But supposing a wheel to raise 
 water by means of cranks and 
 pumps on Mr. Banks's principle, 
 Buchanan thought it might easily 
 
 be demonstrated, that by reducing 
 the velocity of the wheel to a cer- 
 tain degree, the wheel would raise 
 more water than would be neces- 
 sary to move it at that velocity, 
 a thing evidently impossible. 
 
 In this view it would seem that 
 there is no actual case in which 
 Mr. Banks's conclusions will hold 
 true. But, however they may ap- 
 ply to other mills, the experiments 
 of Buchanan seem to prove at 
 least that they do not apply to 
 cotton-mills. On the ground of 
 some experiments made at differ- 
 ent times, and with all the atten- 
 tion possible, did he presume to 
 call in question an authority for 
 which the highest respect is enter- 
 tained. 
 
 In January, 1796, he measured 
 the quantity of water the Rothesay 
 old cotton-mill required; first, when 
 going at its common velocity, and 
 secondly, when going at half that 
 velocity. The result was, that the 
 last required just half the quantity 
 of water which the first did. It 
 is to be observed, that in these 
 experiments the quantities of wa' or 
 were calculated from the heads 
 of water and apertures of the 
 sluices. 
 
 From these experiments he in- 
 ferred, " that the quantity of water 
 necessary to be employed in giving 
 different degrees of velocity to a 
 cotton-mill must be nearly as that 
 velocity." 
 
 He was satisfied with this expe- 
 riment, and the inference drawn 
 from it, till some gentlemen well 
 acquainted with the theory and 
 practice of mechanics expressed 
 their doubts on the subject. He 
 had then recourse to another ex- 
 periment, which he considered less 
 liable to error than the former. 
 
 The water which drives the old 
 cotton-mill falls a little below it 
 into a perpendicular-sided pond, 
 which serves as a dam for a corn- 
 mill at some distance below it. 
 To ascertain, therefore, the proper- 
 
WAT 
 
 WATER-WHEEL. 
 
 WAT 
 
 tional quantities of water used by 
 the old mill, nothing more was 
 necessary than to measure the time 
 the water took to rise to a certain 
 height in that pond ; and accord- 
 ingly, on the 1st of May, 1798, he 
 made the experiments noted in the 
 following Table : 
 
 Number of experi- 
 ments 1234 
 
 Revolutions of one of 
 the upright shafts 
 per minute ... 46 4(5 24 23 
 
 Rise of water in the 
 pond in inches . . 5555 
 
 Time in minutes and 
 
 seconds .... 6 58 6'57 14'45 l&'O 
 
 The first and second experiments 
 were made with the mill at its 
 common velocity ; the third and 
 fourth at nearly half that velocity. 
 
 The time which the mill re- 
 quired to use the same quantity of 
 water in these experiments may 
 be taken, in round numbers, as 
 follows : the proper velocity at 7 
 minutes, and half that velocity at 
 15 minutes. 
 
 The result of these experiments 
 approaches very nearly to that of 
 1796. The difference may be ac- 
 counted for by the small degree of 
 leakage which mubt have taken 
 place at the sluices on the lower 
 end of the pond ; and the time 
 being greater in the third and 
 fourth experiments, the leakage 
 would of course be greater. 
 
 Smeaton and others have proved 
 in a very satisfactory manner, that 
 " the mechanical power that must 
 of necessity be employed in giving 
 different degrees of velocity to the 
 same body, must be as the square 
 of that velocity." But it appeared 
 to Buchanan that the result of the 
 above experiments may be easily 
 reconciled to this proposition, by 
 considering what Smeaton says 
 immediately afterwards : " If the 
 converse of this proposition did 
 not hold true, viz. that if a 
 body in motion, in being stopped, 
 would not produce a mechanical 
 effect equal or proportional to the 
 
 square of its velocity, or to the 
 mechanical power employed in 
 producing it, the effect would not 
 correspond with its producing 
 cause." It is to be observed, 
 that Smeaton's experiments were 
 made on the velocity of heavy 
 bodies, free from friction and of her 
 causes of resistance ; but in mills 
 there is not only friction, but ob- 
 stacles, to be removed : and ex- 
 periments made on friction have 
 proved that the friction of many 
 kinds of bodies increases in direct 
 proportion to their velocity. But 
 the velocity of a cotton-mill at 
 work may be considered as a me- 
 chanical effect; and, if so, must 
 correspond with its producing 
 cause. 
 
 The preceding experiments on 
 the Rothesay mill are undoubtedly 
 correct and consistent with the 
 principles of motion and power, 
 and also with the experiments of 
 Smeaton on mills and mechanical 
 power. 
 
 The mechanical power is as 
 the quantity of water on the 
 wheel, multiplied into its velocity 
 when the wheel, fall, and other 
 circumstances remain the same ; 
 and since the mechanical effect 
 is measured by the resistance mul- 
 tiplied into the velocity of the 
 working point when the friction is 
 constant, if the quantity of water be 
 diminished by its half, either half 
 the resistance, or half the velocity 
 with which it is overcome, must be 
 taken away, otherwise there will 
 not be an equilibrium between the 
 power and effect. But at the same 
 time it is to be observed, that an 
 increased velocity lessens the fric- 
 tion of the intermediate machinery, 
 and consequently a greater effect 
 would be produced by the greater 
 velocity, as appears to be the case 
 by the experiments. There is not, 
 however, in the detail of these ex- 
 periments, sufficient data by which 
 it becomes easy to arrive at any 
 anv useful conclusion. 
 
WAT 
 
 WATER. WHEEL. 
 
 WAT 
 
 Roberton, an engineer of some 
 eminence, made observations on 
 these experiments, alleging that 
 the conclusions of Banks give most 
 satisfactory evidence that particular 
 care and judgment are necessary in 
 making such trials. It appeared 
 to Roberton, that the wrong con- 
 clusions which have been drawn 
 by many writers on this subject, 
 have wholly arisen from misappre- 
 hending someof Sir Isaac Newton's 
 fundamental principles of mecha- 
 nics, and from a love of establish- 
 ing theoretical expressions rather 
 than strict observations of the in- 
 variable laws of nature, expres- 
 sions such as these, viz. quantity 
 of motion, instantaneous impulse. 
 
 Taking a constant portion of 
 time (viz. a second) to be the 
 measure of a body, and an instant 
 to be the measure of the effect it 
 produces ; or by taking time as the 
 measure of the cause, and space as 
 the measure of the effect, as to 
 an instantaneous effect, Roberton 
 argues that it is an absurdity in 
 itself, as well as in mechanics, 
 we can form no idea of a body put 
 into motion without the acting 
 power or body act upon the body 
 put into motion for some time, and 
 also over some space ; and to sup- 
 pose otherwise, leads us entirely 
 out of the sound principles of me- 
 chanics. 
 
 In mechanics every effect is equal 
 to its producing cause. In the case 
 of a power acting on a body pro- 
 ducing motion, and also this body 
 acting against another power which 
 retards its motions, if the causes of 
 action and resistance are each mea- 
 sured by the time the motions are 
 produced and retarded, the result 
 will be equal. 
 
 If they be measured by the 
 space over which they act, the re- 
 sults will be equal ; and this is a 
 universal principle, whether ap- 
 plied to accelerating power and 
 motion, as gravity, etc., or to ma- 
 chines, which act constantly and 
 
 547 ' 
 
 uniformly. Yet. in the case of 
 uniform motion, space or time may 
 be used at pleasure ; as from the 
 uniformity of space and time they 
 become a common measure. 
 
 To illustrate this, suppose the 
 body A acted upon by the power 
 of gravity through the space A B, 
 in a portion of time which we will 
 call one. When it arrives at B, it 
 meets with another medium of re- 
 sistance, which is ten times greater 
 than the former; the body 
 A will be resisted in pro- A Q 
 portion to the cause of ac- 
 tion and resistance ; that 
 is to say, if the time of 
 action were one second, 
 the time of resistance will 
 be one-tenth of a second, 
 and the distance A B will 
 be to the distance B c as 
 ten to one; so that whether 
 space or time be taken as 
 the measure of action, the 
 same must be taken for 
 the measureof the effect 
 to have the results propor- 
 tionate and equal. But 
 if the cause be measured ] 
 by time, and the effect by 
 space, the results will be 
 as the squares of the time, 
 or, which is the same 
 thing, as the squares of the ve- 
 locity. 
 
 Thus, suppose a body in motion, 
 with a velocity of one, has a power 
 to penetrate into a bank of earth 
 1 foot: if the same body, with a 
 velocity of two, strike the bank, 
 will penetrate to the depth of 4 
 feet; for the velocity is double, 
 and the time of action is double, 
 and therefore the results will be 
 compounded of both, that is, as 
 the square of the velocity. 
 
 From the above it may be in- 
 ferred that if equal bodies be acted 
 upon by unequal powers, the time 
 requisite to produce an equal mo- 
 tion will be reciprocally propor- 
 tionate to the powers ; that is to 
 say, if a power of ten act upon a 
 
WAT 
 
 WAT&R-WHEEL. 
 
 WAT 
 
 body for one second of time, and 
 the power of one act upon an equal 
 body for ten seconds, they will pro- 
 duce equal velocities. But the 
 spaces through which the bodies 
 are carried are very unequal, being 
 as ten to one ; and if the square 
 roots of the powers producing the 
 effects be taken, that will give the 
 times they take in carrying the 
 body acted upon through equal 
 spaces. 
 
 But it is obvious this doctrine 
 has no more to do with the ope- 
 ration of machines than to supply 
 their first starting from rest to 
 the motion necessary for working. 
 When this is acquired, the power 
 applied and the power of resistance 
 balance each other, and whatever 
 be the motion the machine moves 
 at, the same power will carry it 
 on, (if it be upheld,) provided the 
 machine act in such a manner as 
 not to accumulate resistance by 
 the accumulation of motion, which 
 is the case in forcing fluids through 
 pipes, etc. In cases of this kind, 
 the nature of the machine must be 
 particularly kept in view, and no 
 law whatever adopted to explain 
 the. resistance the acting body meets 
 with, but what is simply deduced 
 from the very machine which is 
 under consideration ; but, in most 
 cases, any machine may be con- 
 sidered as acting purely on a sta- 
 tical principle. The raising of 
 weights, or overcoming friction, 
 Roberton considers purely as act- 
 ing on that principle; and when 
 the power of action is equal to the 
 resisting power, the machine is in- 
 different to motion or rest. If the 
 machine be at rest, the power will 
 not move it, being a balance to the 
 resistance. If the machine be set 
 in motion, the power will keep it 
 in the same motion, (provided the 
 power be upheld,) the same as 
 equal weights hung over a pulley, 
 or in the opposite scales of a beam. 
 If they be at rest, they will remain 
 so; and if they be put in motion, 
 
 548 
 
 they will endeavour to persevere in 
 the same. 
 
 The above doctrine of a statical 
 principle is proved in the most 
 satisfactory manner by the experi- 
 ments made at the old mill of 
 Rothesay, the motion of the water- 
 wheel being exactly proportional 
 to the quantity of water expended, 
 and therefore an exact and equal 
 load upon the wheel ; that is to 
 say, the bucket* were equally full 
 when the mill moved at its ordi- 
 nary motion, or at half that mo- 
 tion. The effect therefore of letting 
 more water on a wheel is not to 
 lodge a greater quantity in the 
 buckets, but to supply the same 
 quantity when the wheel is in a 
 greater motion. 
 
 Banks, however, made his ex- 
 periments agree with his theory, 
 yet Roberton took no trouble in 
 inquiring into them, alleging it 
 would be to little purpose to have 
 done so. 
 
 "Suffice it to say," he adds, 
 " that the very small quantities of ! 
 water which Banks made use of, I 
 and the slowness of the motion of ! 
 his wheel in his experiments, give 
 no ground for placing the smallest 
 dependence on them ; and when 
 compared with the more judicious 
 and accurate experiments of Smea- 
 ton, they dwindle into contempt." 
 
 Roberton further says, that 
 " Smeaton, in running his wheel ; 
 at nearly 3 feet in the second, ; 
 brought it nearly to a maximum, 
 and lost but about one-fourth or 
 one-fifth of the original effect (al- 
 luding to his overshot wheels). 
 Banks, at his highest motion, ran 
 his wheel about 1 foot in the se- 
 cond, and reducing it to one-half 
 of that motion, the same quantity 
 of water then expended was ca- 
 pable of performing four times the 
 work ; and by deduction from 
 thence, it appears plain that his 
 wheel (from his own theory) would 
 perform about twenty times the 
 quantity of work which Smeaton's 
 
WAT 
 
 WATER-WHEEL, OVERSHOT. 
 
 WAT 
 
 could perform with the same quan- 
 tity of water, and about sixteen 
 times more than nature ; so that 
 the observation (alluding to the 
 theory of Banks) is very just in 
 saying that, by reducing the mo- 
 tion of the wheel, it is demon- 
 strable it would raise more water 
 than supply itself." 
 Water-wheel (Overshot}. The best 
 water-wheel is that which is cal- 
 culated to produce the greatest 
 effect when it is supplied by a 
 stream which furnishes a given 
 
 quantity of water with a given 
 fall. The mechanical effect depends 
 on the proportion of the wheel's 
 diameter to the height of the fall, 
 and on the velocity of the circum- 
 ference of the wheel. These are 
 the two principal parts to be con- 
 sidered in the theory of wheels, 
 but there are also some other points 
 which ought to be attended to, be- 
 cause the effect is much decreased 
 when they are neglected. 
 
 Of the proportion of the radius 
 of the water-wheel to the height of 
 
 the fall. Let A B c D be the wheel, 
 and E A the depth of the buckets ; 
 then, according to experiments on 
 water-wheels, it appears that the 
 rotatory form of the water in the 
 buckets is nothing at c and d, and 
 that it increases nearly, if not ac- 
 curately, in the direct ratio of the 
 distance from c or d, and is greatest 
 at A. That is, the force at any 
 point a in a direction e a, or per- 
 
 pendicularly to the radius, is asac. 
 A slight consideration of the 
 figure is sufficient to demonstrate 
 that the wheel will not produce 
 the greatest effect when it receives 
 the water at the upper point c, and 
 that there must be considerable 
 advantage in making the wheel 
 of a greater diameter, so that it 
 may receive the water at the same 
 point between A and c, the point 
 
 549 
 
 2 A 3 
 
WAT 
 
 XVATER-WHEEL, OVERSHOT. 
 
 WAT 
 
 which will ensure the greatest ef- 
 fect thus calculated. 
 
 Let c = that portion of the cir- 
 cumference which is to be loaded 
 with water ; and x = the arc com- 
 prehended between the point where 
 the water flows upon the wheel 
 and the horizontal line E A ; also 
 make b = the area of the stream 
 supplying the buckets. Then the 
 solid which represents the effective 
 force will be 
 
 2^\ 
 ) 
 
 ? x I 
 
 which is to be the greatest possi- 
 ble ; or 
 
 <? 2jt* 
 
 c x 
 
 a maximum. By the principles 
 of maxima and minima this takes 
 place when 
 
 x = c (1 V^) or x= -2929 c. 
 Accordingly the arc 9 x must be 
 the quadrant dg or 90, and the 
 arc* = 37-27- 
 
 Hence we have this important 
 practical maxim. A water-wheel 
 will produce the greatest effect 
 when the diameter of the wheel is 
 proportioned to the height of the 
 fall, so that the water flows upon 
 the wheel at a point about 52 
 from the sum" rait of the wheel. 
 
 If r be the radius of the wheel 
 to the extreme part of the bucket, 
 and h the effective height of the 
 fall, then h = r (1 + sin. 37$), or 
 h= 1-605 r ; forthe sin. 37$ = '605. 
 Also -623 h = r. Therefore, when 
 the effective height of the fall is 
 determined, the radius of the wheel 
 is easily calculated. When the ef- 
 fective fall is eight-ninths of the 
 whole fall, if we make h the whole 
 fall, r=-554 h, or 1-108 h = the 
 diameter of the wheel. 
 
 The effective height of the fall 
 is less than the true height by as 
 much as is necessary for giving the 
 water the same velocity as the 
 wheel before it flows upon it. 
 
 In low falls a wheel would work 
 
 with advantage in a considerable 
 depth of tail-water, provided the 
 buckets were of a suitable form for 
 moving through the water, and the 
 effective fall made through a very 
 accurate sweep, so that the sweep, 
 and not the form of the bucket, 
 should confine the water upon the 
 wheel. 
 
 Of the velocity of the circum- 
 ference of the wheel to produce a 
 maximum effect. It is necessary 
 to premise, that the velocity with 
 which the water flows upon the 
 floating boards or buckets is con- 
 sidered to be equal to the velocity 
 of the wheel, and to strike against 
 the floats as nearly as possible in 
 the direction of the motion of the 
 wheel. 
 
 Let x be that part of the fall 
 which gives the necessary velocity 
 v to the water, when the effect 
 is a maximum; v will then be 
 the velocity of the circumference 
 of the wheel. Also, make a = 
 that part of the fall which would 
 correspond to the velocity of the 
 circumference of the wheel when 
 the power would be equal to 
 the friction of the loaded machine 
 only ; or when the useful effect 
 would be nothing. Now if h be 
 the whole fall, the effective force 
 of the water on the wheel will 
 always be proportional to h x, 
 when the effect is a maximum ; 
 and to h a, when the useful ef- 
 fect, or work done, is nothing. 
 
 Hence v (h x h a) must 
 be a maximum ; or v (a x) o. 
 max. ; but v = jfi, therefore * 
 (a x} a max., which, according 
 to the rules of maxima and minima, 
 takes place when a = 3.r. 
 
 It is evident that the value of a 
 must entirely depend on the nature 
 of the machine: for if there be 
 many moving parts between the 
 power and the resistance, the fric- 
 tion will be greater.and consequent- 
 ly a will be less. The machine 
 
WAT 
 
 WATER-WHEEL, OVERSHOT. 
 
 WAT 
 
 must be very simple indeed, if the 
 friction be less than one-half the 
 moving power, and it will often 
 amount to two-thirds of it. If we 
 suppose it to be two-thirds, then 
 
 and consequently 
 
 -*, 
 
 and 
 
 Hence, when the friction amounts 
 to two-thirds of the moving power, 
 the velocity of the circumference 
 of an overshot wheel in feet per 
 second, should be 2-67 times the 
 square root of the whole height of 
 the fall, in feet. 
 
 Again, that part of the fall is to 
 be determined, which will give the 
 water the same velocity as the 
 wheel ; and since 
 
 h , Q 
 
 a -, and ox = 
 3 
 
 we have 
 
 Hence, when the friction is two- 
 thirds of the power, that part of 
 the fall which will give the water 
 the proper velocity is one-ninth of 
 the whole height. 
 
 These results may, then, be use- 
 fully compared with the experi- 
 ments of Smeaton ; at the same 
 time it is obvious that his experi- 
 ments were not adapted for arriv- 
 ing at general conclusions, because 
 the water was always delivered 
 upon the same wheel : for it is 
 clear, from the preceding investi- 
 gation, that every particular wheel 
 must have its particular maximum. 
 
 In Smeaton's experiments on 
 overshot wheels, the wheel was 2 
 feet in diameter; therefore the 
 height of the fall should be 2 feet. 
 Now the square root of 2 is T5 ; 
 
 and 1-5 x 2-67 = 4-005, that is, 
 the velocity of the wheel should 
 be 4 feet per second ; or it should 
 make 38 turns per minute. Smea- 
 ton infers that " the best velocity 
 for practice " will be when awheel 
 of 2 feet diameter makes 30 revo- 
 lutions per minute. (Miscellaneous 
 Papers, p. 51.) But his model had 
 much more friction in proportion 
 to the effective force of water on 
 the wheel than two-thirds, here 
 calculated upon. When, however 
 the calculation is made according 
 to the friction of Smeaton's model 
 
 v = 2-4 Jh\ 
 
 and the velocity of the model whee 
 would come out 3-6 feet per second 
 or 34 turns per minute. This ve- 
 locity will perhaps apply correct!) 
 enough to overshot wheels, where 
 the water flows on at the summit 
 and to rough-made machinery ; but 
 the former calculation is that which 
 appears to be most correct for the 
 improved kind of wheels here 
 pointed out. It is to be under- 
 stood, that the friction allowed for 
 includes all the kinds of resistance 
 and loss of force which lessen the 
 useful effect, as well as the resist- 
 ance of the rubbing surfaces, pro- 
 perly called friction. Many persons 
 may think that two-thirds of the 
 effective force is greatly too much 
 to be lost ; it will be well if it draw 
 their attention to lessening the 
 stress on every part of the machi- 
 nery, and to the importance of 
 having few rubbing surfaces, and 
 other causes of resistance. 
 
 On computing the power of over- 
 shot water-wheels. In determin- 
 ing the proportion of the radius of 
 the wheel to the height of the fall, 
 an equation is given for the effec- 
 tive force. Resuming that equa- 
 tion, we have 
 
 = the effective force of the water, 
 and 
 
WAT 
 
 WATBR-WHBEL, OVERSHOT. 
 
 WAT 
 
 = its mechanical power. But the 
 quantity of water expended in 
 maintaining this power will be b v. 
 Hence, the quantity of water ex- 
 pended is, to its mechanical power, 
 as 
 
 1 : 
 
 When the wheel is supplied at 
 the summit, x = c ; and there- 
 fore the quantity of water ex- 
 pended is to its mechanical power 
 as 1 : 2 c. Or the power is equal 
 to half the weight of water sup- 
 plied to the wheel. 
 
 The same relation takes place 
 when x = ; that is, when the 
 wheel is supplied at the height of 
 the axis. Hence, when the radius 
 of a breast-wheel is equal to the 
 effective height of the fall, its 
 power will be the same as that of 
 an overshot wheel supplied at the 
 summit. 
 
 When the wheel is supplied at 
 the point which produces the 
 greatest effect, x 2929 c; and 
 consequently the quantity of water 
 expended is to its mechanical 
 power as 1 . 0-5857 c: this effect 
 is greater than when the wheel is 
 supplied at the summit in the ratio 
 of 1-1714 : 1. 
 
 These comparisons will convey 
 some useful information to many 
 readers ; and they may sometimes 
 suggest to scientific writers the 
 advantage of studying the actual 
 nature of machines ; for relations 
 so extremely obvious and simple 
 could never have been overlooked 
 by any one who might have con- 
 descended to apply himself to an 
 examination of the subject. 
 
 The power of a water-wheel may 
 be considered under two points of 
 view ; each of which has its pecu- 
 liar use. If we wish to compare it 
 with any other first mover, then 
 we bhall have to calculate its me- 
 
 chanical power. But when it is 
 desirable to compute the resistance 
 it will overcome at the working 
 point, the effective force should be 
 calculated. 
 
 When the water flows upon the 
 wheel, either at or above the axis, 
 the mechanical power is 
 2 
 
 c x 
 cubic feet of water, or 
 
 31-25 bv 
 
 -Ibs.; 
 
 where b v is the quantity of water 
 expended in a second, in cubic feet ; 
 c the part of the circumference be- 
 tween the lowest point of the wheel 
 and the place where the water 
 flows upon it, in feet ; and x the 
 part of the circumference between 
 the point which is level with the 
 axis, and that where the water 
 flows upon the wheel, in feet. 
 
 Suppose the mechanical power 
 of ahorse is estimated at 200 Ibs., 
 moving with a velocity of 3 feel 
 per second, then a water-whee: 
 will be equal 
 
 31-25 *,( c >-2^) 
 
 200 X 3f (e - x) 
 00426 b (c 2 - 
 
 c x 
 
 horses. 
 
 When the water flows on either 
 at the summit or at the level of 
 the axis, the mechanical power is 
 31-25 b v c Ibs., or it is = 0-00426 
 b v c horses. 
 
 When the water flows on at 52f 
 degrees distant from the summit, 
 the mechanical power is 37'192 
 b v c Ibs., or = '005 b v c horses. 
 Since in this case c = 127J degrees 
 of the circumference, we have c = 
 x -0174533 r; and as r = 
 
 554 h; and v = 2'67 J~h\ by 
 substituting these quantities, we 
 have 122-176 b h% Ibs. = the me- 
 chanical power; or -0164 bh* = 
 the number of horses, where h 
 
WAT 
 
 WATER-WHEEL, VENTILATED. 
 
 WAT 
 
 the whole height of the fall, in feet, 
 and & = the area of the aperture 
 through which the water flows 
 upon the wheel, in feet. 
 
 The effective force is 31-25 b c 
 Ibs. when the water flows on either 
 at the summit or at the level of 
 the axis. 
 
 When the water flow r s on at 52f 
 degrees distant from the summit of 
 the wheel, the effective force is 
 37-192 b c Ibs. or 45-746 b h Ibs. 
 
 Of the power of breast -wheels. 
 When the water flows on below the 
 level of the axis of the wheel, it 
 may be termed a breast-wheel. 
 
 Let y be the distance below the 
 axis measured on the circumfer- 
 ence, then 
 
 c 2 b v 
 
 equal the mechanical power in 
 cubic feet of water, or 
 
 31-25 c 2 b v 
 
 Ibs. 
 
 c + y 
 
 When y = c the power will be re- 
 duced one-half, and when y = 2 c 
 it will be reduced two-thirds, and 
 so on. 
 
 If we assume that the mechani- 
 cal power of an undershot wheel is 
 half that of an overshot one " under 
 the same circumstances of quantity 
 and fall;" then it will be an ad- 
 vantage to employ an undershot 
 wheel whenever the fall is less than 
 three-tenths of the radius of the 
 wheel. But since the radius of 
 the wheel may in many cases be di- 
 minished, it does not appear to be 
 desirable to employ an undershot 
 wheel in any case, except where 
 the quantity of water is great and 
 the fall inconsiderable. 
 Water-wheel with ventilated Buckets. 
 Since the time of Smeaton's expe- 
 riments in 1759, little or no im- 
 provement has been made in the 
 principle on which water-wheels 
 have been constructed. The sub- 
 stitution, however, of iron for wood, 
 as a material for their construction, 
 
 553 
 
 has afforded opportunities for ex- 
 tensive changes in their forms, par- 
 ticularly in the shape and arrange- 
 ment of the buckets, and has given 
 altogether a more permanent and 
 lighter character to the machine 
 than had previously been attained 
 with other materials. A curvili- 
 near form of bucket has been gene- 
 rally adopted, the sheet iron of 
 which it is composed affording fa- 
 cility for being moulded or bent 
 into the required shape. 
 
 From a work entitled ' Meca- 
 niqueset Inventions approuvees par 
 1' Academic Royale des Sciences,' 
 published at Paris in 1735, it ap- 
 pears, that previous to the com- 
 mencement of the last century, 
 neither the breast nor the overshot 
 water-wheels were much in use, if 
 at all known ; and at what period 
 and by whom they were introduced, 
 is probably equally uncertain. The 
 overshot wheel was a great im- 
 provement, and its introduction was 
 an important step in the perfecting 
 of hydraulic machines ; but the 
 breast-wheel, as now generally 
 made, is a still further improve- 
 ment, and is probably better calcu- 
 lated for effective duty under the 
 circumstances of a variable supply 
 of water, to which almost every 
 description of water-wheel is sub- 
 jected. Improvements have taken 
 place during the last and the pre- 
 sent centuries. The breast-wheel 
 has taken precedence of the over- 
 shot wheel, not so much from any 
 advantage gained by an increase of 
 power on a given fall, as from the 
 increased facilities which a wheel 
 of this description, having a larger 
 diameter than the height of the 
 fall, affords for the reception of 
 the water into the chamber of the 
 bucket, and also for its final exit 
 at the bottom. 
 
 Another advantage of the in- 
 creased diameter is the comparative 
 ease with which the wheel over- 
 comes the obstruction of back- 
 water. The breast-wheel is not 
 
WAT 
 
 WATER-WHEEL, VENTILATED. 
 
 WAT 
 
 only less injured from the effects 
 of floods, but the retarding force is 
 overcome with greater ease, and 
 the wheel works for a longer time 
 and to a much greater depth in 
 back-water. 
 
 The late Dr. Robison, Professor 
 of Natural Philosophy in the Uni- 
 versity of Edinburgh, in treating of 
 water-wheels, says, " There fre- 
 quently occurs a difficulty in the 
 making of bucket-wheels, when the 
 half-taught millwright attempts to 
 retain the water a long time in the 
 buckets. The water gets into them 
 with a difficulty which he cannot 
 account for, and spills all about, 
 even when the buckets are not 
 moving away from the spout. This 
 arises from the air, which must 
 find its way out to admit the water, 
 but is obstructed by the entering 
 water, and occasions a great sput- 
 tering at the entry. This may be 
 entirely prevented by making the 
 spout considerably narrower than 
 the wheel : it will leave room at 
 the two ends of the buckets for the 
 escape of the air. This obstruction 
 is vastly greater than one would 
 imagine ; for the water drags along 
 with it a great quantity of air, as 
 is evident in the water-blast as de- 
 scribed by many authors." 
 
 In the construction of wheels for 
 high falls, the best proportion of 
 the opening of the bucket is found 
 to be nearly as five to twenty-four ; 
 that is, the contents of the bucket 
 being 24 cubic feet, the area of the 
 opening, or entrance for the water, 
 would be five square feet. In 
 breast-wheels which receive the 
 water at the height of 10 to 12 
 above the horizontal centre, the 
 ratio should be nearly as eight to 
 twenty-four, or as one to three. 
 With these proportions, the depth 
 of the shrouding is assumed to 
 be about three times the width 
 of the opening, or three times 
 the distance from the lip to the 
 back of the bucket, as from A to 
 B, fig. 1, the opening being 5 
 
 inches, and the depth of the shroud 
 15 inches. 
 
 Fig. 1. 
 
 For lower falls, or in those wheels 
 which receive the water below the 
 horizontal centre, a larger opening 
 becomes necessary for the recep- 
 tion of a large body of water, and 
 its final discharge. 
 
 In the construction of water- 
 wheels, it is requisite, in order to 
 attain the maximum effect, to have 
 the opening of the bucket suffi- 
 ciently large to allow an easy en- 
 trance and an equally free escape 
 for the water, as its retention in 
 the bucket must evidently be in- 
 jurious, when carried beyond the 
 vertical centre. 
 
 Dr. Robison further observes, 
 " There is another and very seri- 
 ous obstruction to the motion of 
 an overshot or bucketed wheel. 
 When it moves in back-water, it 
 is not only resisted by the water 
 when it moves more slowly than 
 the wheel, which is very frequently 
 the case, but it lifts a great deal 
 in the raising buckets. In some 
 
 554 
 
WAT 
 
 WATER-WHEEL, VENTILATED. 
 
 WAT 
 
 particular states of back-water, the 
 descending bucket fills itself com- 
 pletely with water, and in other 
 cases it contains a very considerable 
 quantity, and air of common den- 
 sity, while in some rarer cases it 
 contains less water, with air in a 
 condensed state. In the first case, 
 the rising bucket must come up 
 filied with water, which it cannot 
 drop till its mouth gets out of the 
 water. In the second case, part 
 of the water goes out before this ; 
 but the air rarefies, and therefore 
 there is still some water dragged 
 or lifted up by the wheel, by suc- 
 tion, as it is usually called. In the 
 last case, there is no such back- 
 load on tlie rising side of the wheel, 
 but (which is as detrimental to its 
 performance) the descending side 
 is employed in condensing air ; and 
 although this air aids the ascent of 
 the rising side, it does not aid it so 
 much as it impedes the descend- 
 ing side, being (by the form of the 
 bucket) nearer to the vertical line 
 drawn through the axis." 
 
 These were the difficulties under 
 which the millwrights of Dr. Ro- 
 bison's time laboured ; and the 
 remedy which they applied (and 
 which has since been more or less 
 continued) was to bore holes in 
 what is technically called the ' start' 
 of the bucket. This was the only 
 means adopted for removing the 
 air from the buckets of overshot 
 wheels, in order to facilitate the 
 admission and emission of the 
 water. In lower falls, where wheels 
 with open buckets were used, or 
 straight float-boards radiating from 
 the centre, large openings were 
 made in the sole-planking, exclu- 
 sive of perforations in each bucket, 
 in order to relieve them from the 
 condensed air. The improved con- 
 struction of the present time is 
 widely different, the buckets being 
 of such a shape as to admit the 
 water at the same time that the 
 air is making its escape. 
 
 During the early part of 1825, 
 
 555 
 
 and the two succeeding years, two 
 iron water-wheels, each of one 
 hundred and twenty horse power* 
 were constructed in Manchester 
 for Messrs. James Finlay and Co., 
 of the Catrine Works, under the 
 auspices of the late Mr. Buchanan, 
 and also for the same Company at 
 Deanston, in Perthshire, of which 
 firm Mr. James Smith (Deanston) 
 was then the resident partner. 
 These wheels are still (1850) in 
 operation ; and taking them in the 
 aggregate, they may probably be 
 considered as some of the most 
 powerful and the most complete 
 hydraulic machines in the United 
 Kingdom. The construction of 
 these wheels, and others for lower 
 falls, first directed attention to the 
 ingress and egress of the water, 
 and led to the improvements which 
 have since been introduced. 
 
 The object of these modifications 
 may be generally stated to have 
 been for the purpose of preventing 
 the condensation of the air, and 
 for permitting its escape, during 
 the filling of the bucket with wa- 
 ter, as also its re-admission during 
 the discharge of the water into the 
 lower mill-race. 
 
 Shortly after the construction of 
 the water-wheels for the Catrine 
 and Deanston Works, a breast- 
 wheel was made and erected for 
 Mr. Andrew Brown of Linwood, 
 near Paisley. In this it was ob- 
 served, when the wheel was loaded, 
 and in flood-waters, that each of 
 the buckets acted as a water-blast, 
 and forced the water and spray to 
 a height of six or eight feet above 
 the orifice at which it entered. 
 This was complained of as a great 
 defect, and, in order to remedy it, 
 openings were cut in the sole- 
 plates, and small interior buckets 
 were attached to the inner sole, as 
 shown at b, b, b, fig. 2. The air in 
 this case made its escape through 
 the openings a, a, a, into the inner 
 bucket, and passed upwards, as is 
 shown by the arrows, through b, b, b, 
 
WAT 
 
 WATER-WHEEL, VENTILATED. 
 
 WAT 
 
 into the interior of the wheel. By 
 these means it will he observed 
 that the huckets were effectually 
 cleared of air whilst they were 
 filling, and that during the ob- 
 structions of back-water, the same 
 facilities were afforded for its re- 
 admission, and the discharge of 
 the water contained in the rising 
 buckets. The effect produced by 
 this alteration could scarcely he 
 credited, as the wheel not only 
 received and parted with the water 
 freely, but an increase of nearly 
 one-fourth of the power was ob- 
 tained, and the wheel, which still 
 remains as then altered, continues, 
 in all states of the river, to per- 
 form its duty satisfactorily. 
 
 The amount of power gained, 
 and the beneficial effects produced 
 upon Mr. Brown's wheel, induced 
 a new and still greater improve- 
 ment in the principle of construc- 
 tion: the first wheel erected on 
 this, which has been called the 
 ' ventilated ' principle, was one de- 
 signed for Mr. Duckworth, at the 
 Handforth Print-Works, in the 
 neighbourhood of Wilmslow, in 
 Cheshire. 
 
 Close-bucketed wheels labour 
 under great difficulties when re- 
 ceiving the water through the 
 
 same orifice at which the air es- 
 capes, and in some wheels the 
 forms and construction of the 
 buckets are such as almost entirely 
 to prevent the entrance of the wa- 
 ter, and to deprive the wheel of 
 half its power. These defects may 
 be easily accounted for where the 
 water is discharged upon the wheel 
 in a larger section than the opening 
 between the buckets : under such 
 circumstances the air is suddenly 
 condensed, and, re-acting by its 
 elastic force, throws back the wa- 
 ter upon the orifice of the cistern, 
 and thus allows the buckets to 
 pass without their being more than 
 half-filled. Several methods have 
 been adopted for relieving them of 
 the air: the most common plan is, 
 by cutting holes in the sole-plates, 
 close to the back of the buckets, 
 or else making the openings be- 
 tween them much wider, in order 
 to admit the water, and at the 
 same time to allow the air to es- 
 cape. All these remedies have 
 been more or less effective ; but 
 they labour under the objections of 
 a great waste of water and much 
 inconvenience, by the water falling 
 from the openings down upon the 
 lower part of the wheel, exclusive 
 of the puffing and blowing when 
 the bucket is filling. 
 
 Other remedies have been ap- 
 plied, such as circular tubes and 
 boxes attached to the sole-plates, 
 which, extending upwards, furnish 
 openings into the interior of the 
 wheel for the air to escape ; but 
 these, like many other plans, have 
 been, to a certain extent, unsuccess- 
 ful, owing to the complexity of 
 their structure, and the inadequate 
 manner in which the objects con- 
 templated were attained. In fact, 
 in wheels of this description it has 
 been found more satisfactory to 
 submit to acknowledged defects, 
 than to incur the trouble and in- 
 convenience of partial and imper- 
 fect remedies. 
 
 In the improvements made by 
 
WAT 
 
 WATER-WHEEL, VENTILATED. 
 
 WAT 
 
 Mr. Fairbairn, these objections are 
 to a great extent removed, and a 
 thorough system of ventilation has 
 been effectually introduced. Be- 
 fore entering upon the description 
 of this new principle of ventilation, 
 it is necessary to remark, that in 
 climates like Great Britain and Ire- 
 land, where the atmosphere is 
 charged with moisture for six or 
 seven months in the year, it is 
 no uncommon occurrence for the 
 rivers to be considerably swollen, 
 and the mills depending upon wa- 
 ter are either impeded or entirely 
 stopped by back-water; while at 
 other times a deficiency of rain re- 
 duces the water-power below what 
 is absolutely required to drive the 
 machinery. On occasions of this 
 kind, much loss and inconvenience 
 are sustained, particularly in mills 
 exclusively dependent upon water 
 as a motive power, and where a 
 number of work-people are em- 
 ployed. 
 
 On the outskirts of the manufac- 
 turing districts, where the mills 
 are more or less dependent upon 
 water, these inconveniences are se- 
 verely felt ; and in some situations 
 these interruptions arise as fre- 
 quently from an excess of water as 
 from a deficiency in the supply. 
 To remedy these evils, reservoirs 
 have been formed, and wheels have 
 been constructed to work in floods ; 
 but although much has been ac- 
 complished for diminishing these 
 injurious effects, and giving a more 
 regular supply in dry seasons, yet 
 the system is still imperfect, and 
 much has yet to be done, before 
 water can be considered equal, as a 
 motive power, to the steam engine, 
 which is always available where 
 the necessary fuel is at hand. It 
 is therefore obvious, that any im- 
 provement in the construction of 
 water-wheels, whereby their forms 
 and requirements may be better 
 adapted to meet the exigencies of 
 high and low waters, will contri- 
 bute much to the efficiency and 
 
 557 
 
 value of mills situated upon rivers 
 subjected to the changes alluded to. 
 Water-tvheels (Ventilated) as adap- 
 ted to low falls. The first wheel 
 constructed upon the ventilated 
 principle was erected at Handforth, 
 in Cheshire, in the summer of 
 1828 : it proved highly satisfactory 
 to the proprietors, Messrs. Duck- 
 worth and Co., and gave such im- 
 portant results as to induce its re- 
 petition, without variation, in cases 
 where the fall did not exceed the 
 semi-diameter of the wheel. 
 
 In the earlier construction of 
 iron suspension wheels by the late 
 Mr. J. C. Hewes, the arms and 
 braces were fixed to the centres by 
 screws and nuts upon their ends, 
 as shown in fig. 3. The arms c, e, 
 passed through the rim b, b, and 
 
 Fig. 3. 
 
 the braces e, e, which traverse the 
 angle of the rim/, /, are, as nearly 
 as possible, in the position and 
 
WAT 
 
 WATER-WHEEL, BREAST. 
 
 WAT 
 
 form adopted by Mr. Hewes. This 
 arrangement, although convenient 
 for tightening up the arms and 
 braces, was liable to many objec- 
 tions, arising from the nuts be- 
 coming loose, and the consequent 
 difficulty of keeping the wheels 
 true to the circle, and the arms 
 and braces in a uniform state of 
 tension : gibs and cotters were 
 therefore substituted for the nuts 
 and screws, and since their intro- 
 duction into the large wheels of 
 the Catrine Works, Ayrshire, the 
 objections have been removed, and 
 the arms and braces are not only 
 perfectly secured, but the peri- 
 phery of the wheel is retained in 
 its true and correct form. 
 
 Having noticed the obstructions 
 offered to the entrance of the wa- 
 ter into buckets of the usual form, 
 and the consequent loss which en- 
 sues from its retention upon the 
 wheel, after its powers of gravita- 
 tion have ceased, it is now neces- 
 sary to show the means whereby 
 those defects were removed, and 
 also to exhibit the relation existing 
 between the breast and the under- 
 shot wheels. These terms have, 
 however, become nearly obsolete, 
 as every description of water-wheel 
 may now be properly called a 
 breast-wheel ; and in every fall, 
 however low, it is generally found 
 advantageous for the water to act 
 by gravitation, and not by impulse, 
 as during the early periods of the 
 industrial arts. 
 
 Water-wheels (Breast), with close 
 Soles and ventilated Buckets. The 
 preceding statements have been 
 principally confined to the form of 
 buckets and description of water- 
 wheel adapted for low falls. It 
 is therefore necessary to describe 
 the best form of breast-wheels for 
 high falls, or those best calculated 
 for attaining a maximum effect on 
 falls varying from one-half to three- 
 fourths of the diameter of the 
 wheel. This is a description of 
 water-wheel in common use, and 
 
 is generally adopted for falls 
 which do not exceed 18 feet in 
 height, and, in most cases, is pre- 
 ferable to the overshot wheel. It 
 possesses many advantages over the 
 undershot wheel, and its near ap- 
 proximation to the duty, or labour- 
 ing force, of wheels of the former 
 description, renders it applicable in 
 many situations, especially where 
 the fall does not exceed 13 or 20 
 feet, and where the wheel is ex- 
 posed to the obstructions of back- 
 water. In the latter case, wheels 
 of larger diameter are best adapted ; 
 and provided sufficient capacity is 
 left in the buckets, such wheels 
 may be forced through the back- 
 water without diminution of speed. 
 Every wheel of this kind should 
 have capacity in the buckets to re- 
 ceive a sufficient quantity of water 
 to force the wheel, at full speed, 
 through a depth of 5 or 8 feet of 
 back-water; and if these provisions 
 are made, a steady uniform speed, 
 under every circumstance of freshes 
 and flood-waters, may be attained. 
 
 Irrespective of the advantages 
 of clearing the buckets of air, ad- 
 ditional benefit is obtained by the 
 facility with which the water is 
 discharged, and the air again ad- 
 mitted, at the bottom of the fall, 
 during the period of the emptying 
 of the bucket into the tail-race. 
 This is strikingly illustrated where 
 the wheels labour in back-water, 
 as the ventilated buckets rise freely 
 above the surface, and the commu- 
 nication being open from one to 
 the other, the action is rendered 
 perfectly free, at almost any depth 
 to which the wheel may be im- 
 mersed. 
 
 In breast- wheels constructed for 
 falls of 25 feet or upwards, the 
 stone-breast is not required, as the 
 buckets are formed with narrow 
 openings, and the lip being ex- 
 tended nearer to the back of the 
 following bucket, the water is re- 
 tained much longer upon the wheel. 
 Under these circumstances, astone- 
 
 558 
 
\VAT 
 
 WATER-WHEEL, BREAST. 
 
 WAT 
 
 breast is of little or no value, when 
 attached to a wheel with close 
 buckets, on a high fall. 
 
 The construction of the breast- 
 wheels, as above described, is al- 
 most exactly similar to that for the 
 lower falls ; malleable iron arms 
 and braces being common to both, 
 as also the axle, shroud, and seg- 
 ments. These, when duly pro- 
 portioned and properly fitted to 
 each other, form one of the strong- 
 est, and probably the most per- 
 manent structures, that can be at- 
 tained in works of this description. 
 Water-wheel (common Breast, not 
 ventilated), as constructed by 
 Messrs. Fairbairn and Ltllie, be- 
 tween the years 1825 and 1827. 
 These wheels were executed upon 
 the plan of the overshot or breast- 
 wheel, taking the water at an ele- 
 vation nearly equal to that of its 
 height. Four wheels of this 
 description were constructed for 
 Messrs. James Finlay and Co., for 
 a fall of 32 feet, at Deanston, in 
 Perthshire, and two others, for the 
 same firm, at the Catrine Works, 
 in Ayrshire, on a fall of 48 feet. 
 Taking into consideration the height 
 of the fall, the Catrine waterwheels, 
 both as regards their power and 
 the solidity of their construction, 
 are, even at the present day, pro- 
 bably among the best and most 
 effective structures of their kind in 
 existence. They have now (1 C50) 
 been at work upwards of twenty 
 years, during which time they have 
 required no repairs, and they re- 
 main nearly as perfect as when they 
 were ereated. 
 
 It was originally intended to 
 have erected four of these wheels 
 at the Catrine Works, but only two 
 have been constructed ; prepara- 
 tions were, however, made for re- 
 ceiving two others, in the event of 
 an enlargement of the reservoirs in 
 the hilly districts, and more power 
 being required for the mills. This 
 extension has not yet been want- 
 ed, as these two wheels are equal 
 
 559 
 
 to 240 horse-power, and are suffi- 
 ciently powerful, except in very 
 dry seasons, to turn the whole of 
 the mills. 
 
 These water- wheels are 50 feet in 
 diameter, 10 feet 6 inches wide in- 
 side the bucket, and 15 inches deep 
 on the shroud ; the internal spur- 
 segments are 48 feet 6 inches dia- 
 meter, 3 inches pitch, and 15 in- 
 ches broad on the cog ; the large 
 spur-wheels are 18 feet 2 inches 
 in diameter, 3 inches in the pitch, 
 and 16 inches wide on the cog; 
 and the pinions are the same width 
 and pitch, but are 5 feet 6 inches 
 in diameter ; the large bevel-wheels 
 are 7 feet in diameter, 3 inches in 
 the pitch, and 18 inches broad on 
 the cog, their proportions being 
 calculated to convey the united 
 power of all the four water-wheels, 
 should the original design ever be 
 completed. 
 
 The water for the supply of the 
 wheels is conveyed from the river 
 Ayr in a canal and tunnel, and 
 from thence, along the side of a 
 rising bank, to the wheel-house. 
 From this point it is conveyed to 
 the water-wheels by a large sheet- 
 iron trough, supported on iruii 
 columns. 
 
 When viewed from the entrance, 
 the two wheels alreadyerected hav^ 
 a very imposing effect, each of them 
 being elevated upon stone piers ; 
 and as the whole of the cisterns, 
 sluices, winding apparatus, gal- 
 leries, etc., are considerably ele- 
 vated, they are conveniently ap- 
 proached in every part. Under 
 the wheels is a capacious tunnel, 
 terminating at a considerable dis- 
 tance down the river. 
 
 Water-wheels on a principle in- 
 troduced by M. Poncelet, have at- 
 tained some considerable reputa- 
 tion on the Continent ; and as Mr. 
 Fairbairn has constructed one of 
 them for Mr. De Bergue, it is ne- 
 cessary to allude briefly to the pe- 
 culiarities it possesses. 
 
 The buckets are of a curvilinear 
 
WAT 
 
 WATER-"WHEEL, BREAST. 
 
 WAT i 
 
 form, and are quite open at the 
 back, without any sole-plate ; so 
 that they are perfectly ventilated. 
 The water impinges upon them 
 at nearly the lowest point of the 
 wheel, the shuttle being arranged 
 to draw upwards ; and as the wa- 
 ter enters, it follows the inside ca- 
 vity of the bucket, rises and falls 
 over into the next in succession, 
 and so on. By this system the 
 force of the water is expended on 
 the wheel itself, instead of losing 
 much of its power in rushing along 
 through the wheel-race, as ge- 
 nerally occurs in even well-made 
 undershot wheels. 
 
 M. Poncelet has treated this 
 subject at much length in his able 
 work on water-wheels ; but it may 
 be observed, that a practical im- 
 provement might be effected by 
 terminating the lower stone plat- 
 form of the race somewhat short 
 of the vertical line of the centre 
 of the wheel, as the escape of the 
 water would be facilitated, and the 
 ascending buckets would be more 
 easily relieved of their contents: 
 this is a point of such importance 
 for all wheels, that it must equally 
 apply to this form. 
 
 Mr. De Bergue obtained nearly 
 seventy-eight per cent, of power 
 from a breast- wheel, with a good 
 fall, when the periphery was tra- 
 velling at a velocity of 6 feet per 
 second. 
 
 He has erected several of Ponce- 
 let's wheels, and thought well of 
 them ; indeed, for certain situa- 
 tions it was thought they were pre- 
 ferable to any other form, although 
 M. Poncelet had never yet been 
 able to obtain very superior results 
 from wheels erected under his own 
 superintendence. 
 
 Mr. De Bergue has explained the 
 construction of a wheel, on this 
 principle, erected at the Loubre- 
 gat, near Montserrat, in Catalonia ; 
 one of the same kind having been 
 already erected by him at Gerona, 
 between Barcelona and Belgrade. 
 
 The diameter was 16 feet 8 
 inches, and the width was 30 feet, 
 which, with a fall of 6 feet 6 
 inches, passed 120,000 cubic feet 
 of water per minute, when the 
 periphery travelled at a velocity of 
 11 to 12 feet per second. An or- 
 dinary breast-wheel would require 
 to be 60 feet wide, to use advan- 
 tageously that quantity of water. 
 It was found that the velocity of 
 the periphery should be about 55 
 per cent, of that of the water flow- 
 ing through the sluice ; and upon 
 these data the power of the wheel 
 would be about 180-horse power. 
 
 The buckets were of a curved 
 form, and made of wrought iron, 
 th of an inch thick ; and it should 
 be observed that there was a larger 
 number of buckets than usual, and 
 that the water came upon them 
 at a tangent, through an orifice of 
 such a form and dimensions as to 
 allow the buckets to fill easily, at 
 the rapid speed at which the peri- 
 phery passed before the sluice. 
 This great primary velocity was 
 very important, as it caused a con- 
 siderable saving in the gearing of 
 the mill. 
 
 The main shaft was formed by 
 a hollow cylinder of cast iron, 4 
 feet 6 inches diameter, in short 
 lengths, bolted together; and the 
 arms were of wrought iron, made 
 very light, and of the same form 
 as those of a paddle-wheel of a 
 steamer, and placed very close to- 
 gether. The strain was brought 
 entirely upon the main shaft, and 
 the weight of the wheel was thus 
 reduced to about thirty tons, which 
 was very little for so powerful a 
 machine. 
 
 The sluice was formed of cast- 
 iron plates, with planed joints, 
 bolted through the flanches, to- 
 form one large shuttle of the en- 
 tire breadth of the wheel, and its 
 motion was regulated by radial tie- 
 rods, between the stone apron and 
 the back of the sluice, which could 
 thus be raised with great facility 
 
WAV 
 
 WEALDEN. 
 
 WEI 
 
 by racks and pinions, and be re- 
 gulated by the ordinary governor, 
 the weight of the sluice being in 
 a great degree supported by the 
 water flowing beneath it on to the 
 wheel. It moved very accurately 
 between the side walls of the pen- 
 trough, and cup-leathers at each 
 side prevented any waste of water. 
 This kind of wheel was less 
 affected by back-water than any 
 other form, and the water acted 
 upon it with its full power of 
 velocity, without any impediment 
 from the air in entering, as there 
 was no sole-plate: the buckets 
 filled and emptied with great fa- 
 cility. It is therefore most satis- 
 factory for all falls under 8 feet in 
 height, though the principle dif- 
 fers essentially from that generally 
 taken as the basis of construction 
 of water-wheels. 
 
 Waved, in heraldry, an indented out- 
 line, indicating honours originally 
 acquired at sea. 
 
 Way-shaft, in steam engines, the 
 rocking-shaft for working the slide- 
 valve from the eccentric. 
 Wax, the substance of which the 
 honeycombs of bees are composed, 
 and which is of considerable use in 
 branches of art. 
 
 Wealden. Beneath the two great 
 divisions of the Cretaceous system, 
 and consequently of very ancient 
 date, there occurs in England an 
 important series of beds, chiefly 
 of lacustrine or fluviatile origin, 
 known as the Wealden. Before 
 the submergence of what are now 
 the south-eastern parts of England, 
 first beneath the comparatively 
 shallow greensand, and then be- 
 neath the profounder depths of the 
 ocean of the chalk, a mighty river, 
 the drainage of some unknown 
 continent, seems to have flowed 
 for many ages along tKose parts 
 of Kent, Surrey, and Sussex, 
 known as the Valley of the \Veald. 
 The banks of this old nameless 
 river were crossed with forests of 
 coniferous trees of pine and aran- 
 
 562 
 
 carian families, with cycadea3 and 
 ferns, and were haunted by gigan- 
 tic reptiles, herbivorous and car- 
 nivorous, some of which rivalled 
 in bulk the mammoth and the ele- 
 phant; its waters were inhabited 
 by amphibia of the same great 
 class, chiefly crocodiles and chelo- 
 nians of extinct species and type, 
 by numerous fishes too of the 
 old Ganoid order, and by shells 
 whose families, and even genera, 
 still exist in our pools and rivers, 
 though the species be all gone. 
 Winged reptiles too occasionally 
 flitted amid its woods, or sped 
 over its broad bosom ; and insects 
 of the same family as that to which 
 our dragon-flies belong, spent the 
 first two stages of their existence 
 at the bottom of its pools and 
 shallows, and the terminal one in 
 darting over it on their wings of 
 delicate gauze, in quest of their 
 prey. It is stated by Dr. Mantel], 
 our highest authority on the sub- 
 ject of the W r eald, that the delta* 
 of this great river is about two 
 thousand feet in thickness, a 
 thickness which quadruples that 
 of the delta of the Mississippi. 
 The American " Father of Waters" 
 is a very ancient river ; and yet it 
 would seem that this river of the. 
 Wealden, which has now existed 
 for myriads of ages, is but its fos- 
 silized remains, hidden under the 
 wolds of Surrey and Kent. This 
 old river, which flowed over where 
 the ocean of the Oolite once had 
 been, and in turn gave place, am: 
 was overflowed by the ocean oJ 
 the chalk, continued to roll its 
 downward waters amid forests as 
 dense and as thickly inhabited as 
 those of the great American vallej 
 during a period perhaps four times 
 as extended. 
 Weathercock, a vane made in the 
 
 shape of a cock. 
 
 Weather-gage, in navigation. When { 
 ship is to windward of another 
 she is said to have the weather 
 gage of her. 
 
vVEI 
 
 WEIGHTS AND MEASURES. 
 
 WEI 
 
 Weather-moulding, a label, canopy, or 
 drip-stone, over a door or window, 
 intending to keep off water from 
 the parts beneath. 
 Wedge. The wedge is a solid piece 
 of wood or metal, generally made 
 in the form of a triangle prism, of 
 which the two ends or bases are 
 equal and similar plane triangles, 
 and the three sides rectangular 
 parallelograms : and it is called 
 rectangular, isosceles, or scalene, 
 according as its equal and similar 
 bases are composed of right angles, 
 isosceles, or scalene triangles. As 
 a mechanical power, the wedge 
 performs its office, sometimes in 
 raising heavy bodies, but more fre*- 
 quently in dividing or cleaving 
 them ; hence all those instruments 
 which are used in separating the 
 parts of bodies, such as axes, adzes, 
 knives, swords, coulters, chisels, 
 planes, saws, files, nails, spades, 
 etc., are only different modifica- 
 
 ! tions that fall under the general 
 
 I denomination of the wedge. 
 
 \Weighboard, in mining, clay inter- 
 
 [ secting a vein. 
 
 Weight and power, when opposed to 
 one another, signify the body to 
 
 ' be moved and the body that moves 
 it. That body which communi- 
 
 ; cates the motion is called the 
 power, and that which receives it 
 the weight. 
 
 Weights and Measures. The system 
 of weights and measures used in 
 France at present, in all legal 
 transactions, is called the ' me- 
 trical system,' from the fact of its 
 being based upon the unityof length, 
 which is designated ' the metre.' 
 
 Before the great revolution of 
 1793, the separate provinces of the 
 French kingdom had their different 
 systems of measures: just as in 
 E'ngland the different counties had 
 theirs, before the introduction of 
 the imperial measures. There was, 
 consequently, the same confusion 
 attached to the meanings of the 
 different terms employed, which 
 led our own Government to sim- 
 
 563 
 
 plify the question. An acre in 
 Normandy did not mean the same 
 as an acre in Picardy ; a pound in 
 Paris differed from a pound else- 
 where. But here the analogy be- 
 tween the conduct of the two 
 Governments ceases. That "of 
 France reformed the whole system 
 of weights and measures, and based 
 the new one upon natural and easily 
 verifiable principles, whilst our 
 own retained the arbitrary and illo- 
 gical system of the middle ages, 
 contenting themselves with merely 
 fixing a sort of uniformity in the 
 definitions of the several terms. 
 
 The merit of having originated 
 the metrical system is due to the 
 government of Louis XV., who 
 named a commission to pursue the 
 investigations necessary to decide 
 the principles upon %vhich it was 
 to be carried out. After a very se- 
 rious consideration of the case, and 
 a numerous series of observations 
 carried on during the reign of 
 Louis XVI. and under the Con- 
 vention, the Academy of Sciences 
 decided that all the different 
 weights, measures, and coinages 
 should be established according to 
 certain definite relations to the di- 
 mensions of the globe itself. These 
 are, to all human perception, inva- 
 riable. If therefore the standard 
 were lost, it is always possible to 
 refind it, by a repetition of the same 
 sort of observations which gave rise 
 to the fixing it in the first instance. 
 The beat of a pendulum, chosen by 
 our own Astronomical Board, is a 
 very uncertain base for such calcu- 
 lations ; for the conditions of the 
 vacuum, the temperature of the 
 atmosphere, the specific gravity of 
 the pendulum, nay, perhaps, even 
 the magnetic currents, may affect 
 the length of the space it goes 
 through, in a manner able to af- 
 fect calculations which require 
 such mathematical exactitude as 
 those connected with ascertaining 
 the standard of a perfect system of 
 measures. 
 
WEI 
 
 WEIGHTS AND MEASURES. 
 
 AYE I 
 
 The length of the earth's meri- 
 dian was ascertained by Messrs. 
 Delambre and Mechain, in the por- 
 tion between Dunkerque and Bar- 
 celona ; and by Messrs. Arago and 
 Biot, in the portion between Bar- 
 celona and Formentera. The length 
 of the meridian from the pole to the 
 equator, passing through Paris, was 
 then divided into ten million parts ; 
 and one of these parts, called the 
 metre, became the basis of the new 
 system of weights and measures. 
 Maupertuis had previously, in the 
 year 1736, measured a portion of 
 the arc of a meridian passing 
 through the North Cape, and his 
 observations were combined with 
 those of the second commission. 
 In spite of all this care, however, 
 an error was made in fixing the 
 length of the metre ; for the dis- 
 tance from the equator to the j>ole 
 is really 10,000,738 metres, instead 
 of 10,000,000. For any practical 
 purpose, however, this error is in- 
 applicable ; but it is very unfortu- 
 nate. 
 
 The length of the metre once as- 
 certained, the other measures were 
 derived from it. All the multiples 
 and sub-multiples were formed on 
 the decimal system, and respec- 
 tively designated by Greek and 
 Latin prefixes to the name of the 
 unities. Thus, the multiples of the 
 metre are the rfeea-metre, ten me- 
 tres ; the Aee/o-metre, a hundred 
 metres ; the JhTo-metre, a thousand 
 metres; the wyn'a-metre, ten thou- 
 sand metres. In deference to old 
 customs the term ' league' has 
 been retained, and a legal value of 
 four kilometres affixed to it. 
 
 The sub-multiples of the metre 
 are : the deci-metre, the tenth part 
 of a metre ; the centi-metre, the 
 hundredth part of a metre ; and the 
 milli-metre, the thousandth part of 
 a metre. 
 
 The same prefixes are, of course, 
 applicable to all the other uni- 
 ties. 
 
 The unities of length in use for 
 
 564 
 
 ascertaining the distances of places, 
 are, as said before, the metre (the 
 kilometre and the myriametre) and 
 the league. 
 
 The unity of surface is the ' are,' 
 which is a square of ten metres on 
 a side, or one hundred superficial 
 metres. The usual multiples and 
 sub-multiples are, the hect-are, a 
 square of one hundred metres on a 
 side ; and the m*/i-are, the metre 
 superficial. The terms usually em- 
 ployed in the sale of land and in 
 agricultural discussions, are simply 
 those named above. 
 
 The unity of weight is the 
 ' gramme,' which is the equivalent 
 of a cube of distilled water (at a 
 temperature of 4 above the ' ice- 
 melting point' of the centigrade 
 scale), measuring acentimetre every 
 way. The multiples and sub-mul- 
 tiples are, as before : the deca- 
 gramme, ten grammes ; the hecto- 
 gramme, a hundred grammes ; the 
 kilogramme, a thousand grammes; 
 the decigramme, a tenth part of 
 a gramme, etc. A thousand kilo- 
 grammes, then, would form a cube 
 equal to one measuring a metre 
 on every side ; and it is made the 
 legal ton for heavy weights. 
 
 The unity of capacity is the 
 1 litre,' which is the equivalent of a 1 
 cube measuring one-tenth part of 
 a metre, or a decimetre, every way. 
 The multiples and sub-multiples 
 are formed as before. They are, 
 the decalitre, the hectolitre, the 
 kilolitre, the decilitre, and the cen- 
 tilitre, etc. The litre is usually 
 employed in expressing the quan- 
 tities of liquids; the hectolitre in 
 expressing those of grain. 
 
 A thousand litres of water thus 
 are equal to a metre cube every 
 way, and are one ton in weight. 
 Another advantage in this system 
 is, that the tables of specific gra- 
 vity serve at once to ascertain the 
 weights of the different substances. 
 Thus, inasmuch as- the specific 
 gravity of cast iron is 7202, the 
 weight of a metre cube is at once 
 
WEI WEIGHTS AND MEASURES. WEI 
 
 7202 kilogrammes, or 7 tons 202 
 kilogrammes. 
 
 The ' franc,' the unity of the 
 French coinage, is 5 grammes in 
 weight of an alloy containing nine 
 parts of pure silver to one of alloy, 
 being thus connected with the 
 whole metrical and decimal system. 
 
 As investigations connected with 
 the supply of water are of great 
 importance, it may be added, that 
 the quantity reckoned as the unity 
 in such calculations is the module 
 or 20 cubic metres ; being nearly 
 
 the equivalent of the old ' ponce 
 fontanier,' or the quantity usually 
 delivered by a hole of one inch 
 diameter in the 24 hours. 
 
 The law promulgating the me- 
 trical system was dated in the year 
 1795. The forced application of 
 it in legal transactions did not take 
 place till nearly 50 years after- 
 wards. 
 
 A Table is subjoined of the dif- 
 ferent French weights and mea- 
 sures, with the corresponding Eng- 
 lish equivalents. 
 
 Weights and Measures French, with their English equivalents. 
 FRENCH. WEIGHT. ENGLISH. 
 
 f a thousand grammes, or a cube 
 Kilogramme . . . 
 
 La toon. .... 
 
 ENGLISH TROY. RECIPROCALLY. FRENCH. 
 
 Grain ..... equal to ..... 0-06477 gramme 
 
 Pennyweight . . ,, . . . t . 1 '55456 ,, 
 
 Ounce ..... ,, ..... 31-0913 grammes 
 
 Pound Troy (Imperial) ..... 0-3730756 kilogramme 
 
 AVOIRDUPOIS. 
 Drachm .... equal to ..... 17712 gramme 
 
 Ounce ..... ,, ..... 28-3384 grammes 
 
 Pound ..... ..... 0-4534148 kilogramme 
 
 Hundredweight ..... 507826 kilogrammes 
 
 Ton '.... ..... 1015-649 
 
 To convert pounds avoirdupois into kilogrammes, or English tons into French tons, 
 
 or vice versa, multiply or divide as follows : 
 For pounds, by ...... 0*4534148 
 
 For tons, by ...... 1-015649 
 
 FRENCH. LENGTH. ENGLISH. 
 
 {about 40,000,000 th part of cir-"| 
 cumference of the globe, or I 3*2808992 feet 
 10-millionth part of a quarter f 1-093633 yard 
 of do. J 
 
 Kilometre .... one thousand metres . . . 1093*633 yards 
 
 Myriametre . . . .ten thousand metres . . . 10936'33 yards 
 
 Centimetre .... one-hundredth of a metre . 393708 inch 
 
 Millimetre .... one-thousandeth of a metre . 0'0393708 inch 
 
 ENGLISH. RECIPROCALLY. FRENCH. 
 
 The inch .... one-twelfth of a foot English . 2*539954 centimetres 
 
 f oot .......... 3*0479449 decimetres 
 
 " yard '. . . . 3 feet ...... 0'91438348 metre 
 
 furlong . . . . 320 yards ..... 201-16437 metres 
 
 " mile . . . .1760 yards ..... l609'3149 metres 
 
 To reduce English measure into French, multiply by ; and to reduce French measures 
 
 into English, divide by: 
 Inches to centimetres . . 2-5400 
 
 Feet to metres . . . 0-3047945 practically 0'3048 
 Miles to kilometres . . 1'6093 
 Feet square to metres square 0*09290 
 
 / A yard cube equals 
 cube to metres cube . 0-028314 ..... \ 0' 76458 metre cube 
 
 RfiS 2 B 
 
WEI 
 
 WEIGHTS, COMPARATIVE. 
 
 WEI 
 
 FRENCH. 
 
 Centiare 
 
 Are 
 
 Hectare 
 
 ri96033 yards 
 0-098845 rood 
 3 47 11 43 acres 
 
 ENGLISH. 
 
 uperficial 
 
 A yard square 
 The rod, or . 
 
 rood 
 
 acre 
 
 SURFACE. 
 
 a metre superficial 
 a square of 10 metres every side 
 - 100 
 
 RECIPROCALLY. 
 
 contains 0-88697 mfctre square 
 
 perch square .... 25 -291939 metres square 
 
 1210 yards square . . . 10-116/75 ares 
 do. 
 
 4840 do. 
 
 0-404671 hectare 
 
 In round numbers, the hectare may be taken as equal to 2 acres. 
 
 FRENCH. 
 
 CAPACITY. 
 
 ENGLISH. 
 
 Litre . 
 
 Decalitre 
 Hectolitre 
 
 f a cube of one-tenth of a metre i 1 760773 pint 
 \ on a side . . . . J 0-2200967 gallon 
 
 ten litres 2-2009663 gallons 
 
 one hundred litres . . . 22'00966s 
 
 ENGLISH. RECIPROCALLY. FBENCH. 
 
 Pint equal to 0-567932 litre 
 
 Quart P135864 
 
 Gallon Imperial ... 4-54345794 litres 
 
 Chaldron , . 1 3-085 166 hectolitres 
 
 To turn pressure calculated in pounds per inch superficial into their equivalents calculated 
 in kilogrammes per centimetre superficial, or vice versa, multiply, or divide, by 0-07027/4. 
 
 Weight in pounds of one cubic foot of the following substances : 
 
 Cast iron .... 450' Water 62-5 
 
 Wrought iron . . . 486' Air 0*075 
 
 Steel 489- Steam 0*036 
 
 Pine wood .... 29'5 
 
 Weight of a Superficial Foot of Plate or Sheet Iron. 
 
 No. of the 
 wire- gauge. 
 
 Thickness 
 in inches. 
 
 Weight in 
 pounds. 
 
 No. of the 
 wire-gauge. 
 
 Thickness 
 in inches. 
 
 Weight in 
 pounds. 
 
 
 1 
 
 40' 
 
 12 
 
 
 4-38 
 
 
 T. 
 
 35- 
 
 13 
 
 
 3-75 
 
 
 J 
 
 30- 
 
 14 
 
 
 3-12 
 
 
 i* 
 
 27-5 
 
 15 
 
 
 2-82 
 
 
 1 
 
 25- 
 
 16 
 
 Ta 
 
 2-50 
 
 
 A 
 
 22-5 
 
 17 
 
 
 2-18 
 
 
 * 
 
 20- 
 
 18 
 
 
 1-86 
 
 
 A 
 
 17-5 
 
 19 
 
 
 1-70 
 
 
 i 
 
 15- 
 
 20 
 
 
 1-54 
 
 1 
 
 fr 
 
 12-5 
 
 21 
 
 
 1-40 
 
 2 
 
 
 12- 
 
 22 
 
 A 
 
 1-25 
 
 3 
 
 
 11- 
 
 23 
 
 
 1-12 
 
 4 
 
 i 
 
 10- 
 
 24 
 
 
 1- 
 
 5 
 
 
 874 
 
 25 
 
 
 0-9 
 
 6 
 
 
 8-12 
 
 26 
 
 
 0-8 
 
 7 
 
 A 
 
 7-5 
 
 27 
 
 
 0-72 
 
 8 
 
 
 6-86 
 
 28 
 
 A 
 
 0-64 
 
 9 
 
 
 6-24 
 
 29 
 
 
 0-56 
 
 10 
 
 
 5-62 
 
 30 
 
 
 0-50 
 
 11 
 
 i 
 
 5- 
 
 
 
 
WEI WELDING. WEL 
 
 Weight of Rod Iron 1 foot in length, of the following Dimensions. 
 
 
 SQUARE IRON. 
 
 ROUND IRON. 
 
 FLAT IRON. 
 
 
 
 Inch. 
 
 Pounds. 
 
 Inch. 
 
 Pounds . 
 
 Inch. 
 
 Pounds. 
 
 
 
 I 
 
 0-2 
 
 * 
 
 0-14 
 
 *x 
 
 0-8 
 
 
 
 
 0-5 
 
 i 
 
 0-4 
 
 1 
 
 1-3 
 
 
 
 1 
 
 0-8 
 
 i 
 
 0-7 
 
 * 
 
 1-7 
 
 
 
 
 1-3 
 
 f 
 
 1- 
 
 f 
 
 2-1 
 
 
 
 1 
 
 3-9 
 
 i 
 
 1-5 
 
 
 
 2-5 
 
 
 
 I 
 
 2-6 
 
 i 
 
 2- 
 
 * 2 
 
 1-7 
 
 
 
 
 3-4 
 
 
 2-7 
 
 f 2 
 
 2-5 
 
 
 
 1 
 
 4-3 
 
 H 
 
 3-4 
 
 i 2 
 
 3-4 
 
 
 
 H 
 
 5-3 
 
 U 
 
 4-5 
 
 f 2 
 
 4-2 
 
 
 
 If 
 
 6-4 
 
 it 
 
 5- 
 
 f 2 
 
 5-1 
 
 
 
 H 
 
 7-6 
 
 li 
 
 6- 
 
 * 3 
 
 2-5 
 
 
 
 If 
 
 8-9 
 
 if 
 
 7- 
 
 t 3 
 
 3-8 
 
 
 
 1* 
 
 10-4 
 
 if 
 
 8-1 
 
 i 3 
 
 5-1 
 
 
 
 11 
 
 11-9 
 
 if 
 
 9-3 
 
 f 3 
 
 6-3 
 
 
 
 2 
 
 13-5 
 
 2 
 
 10-6 
 
 f 3 
 
 7-6 
 
 
 
 2* 
 
 17-1 
 
 2* 
 
 13-5 
 
 * 4 
 
 3-4 
 
 
 
 2i 
 
 21-1 
 
 H 
 
 16-7 
 
 f 4 
 
 5-1 
 
 
 
 2f 
 
 25-6 
 
 2f 
 
 20-1 
 
 i 4 
 
 6-8 
 
 
 
 3 
 
 30-4 
 
 3 
 
 23-9 
 
 f 4 
 
 8-4 
 
 
 
 3* 
 
 41-4 
 
 3* 
 
 32-5 
 
 f 4 
 
 10-1 
 
 
 
 4 
 
 54-1 
 
 4 
 
 42-5 
 
 i 5 
 
 4-2 
 
 
 
 5 
 
 84-5 
 
 5 
 
 66-8 
 
 t 5 
 
 6-3 
 
 
 
 6 
 
 121-7 
 
 6 
 
 95-6 
 
 i 5 
 
 8-4 
 
 
 
 7 
 
 165-6 
 
 7 
 
 130- 
 
 f 5 
 
 10-6 
 
 
 
 8 
 
 216-3 
 
 8 
 
 169-9 
 
 t 5 
 
 12-7 
 
 
 Welding, the operation of combining 
 or joining two pieces of iron or 
 steel, by bringing the surface to be 
 joined to a heat nearly equal to 
 that of fusion. 
 
 between the chalk range called the 
 Wolds, and the sea, is a case in 
 point. It was discovered, perhaps 
 accidentally, in sinking through 
 the clay to the subjacent chalk, 
 
 Well, in ship-building, a partition to 
 enclose the pumps, from the bot- 
 tom to the lower decks, to render 
 
 that water rose to the surface in 
 a perpetual fountain, and an am- 
 ple supply was obtained over the 
 
 them accessible, and prevent their 
 taking damage. 
 Wells. The practice of boring for 
 water, adopted in the province of 
 Artoise, in France, has given the 
 denomination to those wells which 
 
 whole of that district by the sim- 
 ple operation of boring. 
 A number of wells of this de- 
 scription have also been executed 
 in the neighbourhood of London 
 by performing the London clay in- 
 
 are termed Artesian. Wells on 
 
 to the porous bed of the plastic 
 
 this principle are very applicable in 
 low level districts covered with 
 
 clay formation, and into the chalk. 
 The principle of operation is 
 
 alluvial deposit or clay; in such 
 situations springs are seldom found, 
 and water cannot be obtained by 
 sinking an ordinary well, unless at 
 a disproportionate cost. The east- 
 ern part of Lincolnshire, which lies 
 
 simply this. The hole is bored 
 through impervious strata that do 
 not contain water, into lower strata 
 that are fully charged with it, and 
 the water rises by hydrostatic pres- 
 sure. The height to which it will 
 
 567 
 
 2 B 2 
 
WEL 
 
 WELL-SINKING. 
 
 WEL 
 
 rise obviously depends upon the in- 
 clination of the strata, and other 
 causes which affect the relative 
 levels of the hole that is made, and 
 the subterraneous body of water 
 that has been tapped. 
 
 Under most circumstances it is 
 pecessary to protect the perforation 
 that is made by sinking iron pipes. 
 The boring is thus secured against 
 the accident of the sides falling in, 
 and another advantage, which is 
 of some importance, is obtained : 
 it may chance that the object is to 
 obtain a supply of soft water which 
 has been ascertained to exist at 
 a certain level, and that the strata 
 which have to be pierced to get to 
 it contain hard or impure water ; 
 in such a case the boring would be 
 continueddown to theproperdepth, 
 and the pipes being plunged into 
 the soft water, it would rise through 
 them, and any water or impurity 
 which might be found in the strata 
 through which they passed would 
 be effectually excluded. If it so 
 happened that at a certain depth 
 belowthe soft water amineral water 
 could be obtained, instead of going 
 to the expense of a fresh bore 
 from the surface, it would only be 
 necessary (supposing that both 
 would flow to the same level) to 
 bore through the pipes already 
 fixed, to the mineral water, and 
 insert smaller pipes within the 
 larger ones, for bringing it up to 
 the surface. 
 
 The history of the great Artesian 
 well which was completed at Cre- 
 nelle is one of the most remark- 
 able instances of confidence in the 
 principle, and of perseverance in 
 execution, that is on record. The 
 facts are believed to be substantially 
 as follows : A person suggested 
 to the authorities, that an Artesian 
 well would supply water in a situa- 
 tion where it was greatly required ; 
 and after some discussion it ended 
 in his undertaking the work on 
 the stipulation, " No water, no 
 pay." He bored down far beyond 
 
 the point at which he expected to 
 have terminated his labours ; but 
 no signs of water appeared : he 
 persevered, however, till he found 
 that the expenses had ruined him. 
 Under these circumstance, he 
 consulted the celebrated Arago, 
 who encouraged him to proceed. 
 Again he went to work, and after 
 unparalleled difficulties, at the ex- 
 piration of six years, and at the 
 depth of 1800 feet, the superin- 
 cumbent mass was bored through, 
 and the water came boiling up in 
 such quantities, and with such 
 force, as to flood the whole district. 
 
 The water, when first obtained, 
 was extremely foul : the partial in- 
 troduction of an Indian-rubber 
 hose is said to have remedied this, 
 and the water thus procured from 
 the main spring was quite pure, 
 and at a very high temperature. 
 Well-sinking. The process of boring 
 may be thus briefly described : 
 
 The auger, the chisel, or any of 
 the great variety of implements 
 which are required to meet differ- 
 ent circumstances and overcome 
 the numerous difficulties which are 
 experienced, are screwed to iron 
 rods, which are usually from 2 to 
 2i inches square. 
 
 The first rod which is attached 
 to the tool is generally about 6 feet 
 long, and the others are of the 
 uniform length of 20 feet. Each 
 rod has a screw at one end, and a 
 tapped socket to receive a screw at 
 the other, and they fit universally ; 
 there is also a 'middle knob' in 
 the centre of each rod, which is 
 used for suspending the rods al- 
 ready fixed, whilst others are being 
 added or detached, as the imple- 
 ment is lowered into the bore, or 
 drawn out of it. 
 
 In commencing operations, a 
 stage about 8 or 10 feet square, 
 and 20 feet high, is erected, when 
 the boring takes place from the 
 surface. The men who work the 
 tool stand upon this stage, and 
 a windlass or crab is fixed, chiefly 
 
WEL 
 
 WHARF. 
 
 WHA 
 
 for hoisting and lowering the rods, 
 but mechanical power is also re- 
 quired for assisting in the working 
 when the depth is very great. 
 
 A boring handle is attached to 
 the rod, which is used for turning 
 the tool round in boring with an 
 auger, or in 'jumping,' as is re- 
 quired when cutting through rock 
 or indurated clay with the chisel. 
 When the boring has proceeded 
 till it is found difficult to turn the 
 rods, or at such times as practical 
 experience dictates, it is necessary 
 to draw out the implements and to 
 bring up the loose material that 
 may be at the bottom of the bore. 
 
 Under ordinary circumstances a 
 common windlass, or a small crab, 
 gives sufficient power to work, 
 hoist, and lower the rods ; but 
 when the bore is of great depth, or 
 the instruments of unusual size, an 
 increase of mechanical power is ne- 
 cessary. This may be conveniently 
 obtained by placing a second crab 
 on another stage ; or, in extraordi- 
 nary cases, horses may be applied 
 on the surface. 
 
 An economical mode of boring 
 has been adopted with success on 
 some parts of the Continent by 
 using a heavy cast-iron bar, 2 cwt. 
 or more, armed with a chisel at 
 the lower end, and surrounded by 
 a cylinder or hollow chamber, 
 which receives through valves and 
 brings up the detritus of the per- 
 forated stratum. This implement 
 is suspended over a wheel or pulley 
 fixed above the spot in which the 
 hole is made, and is raised up and 
 let fall by manual labour. 
 
 As the rope is raised up and 
 down, its tortion gives the chisel 
 a circular motion, which varies the 
 place of cutting at each descent. 
 When the chamber is full, the 
 whole apparatus is raised quickly 
 to the surface, and the material 
 it contains discharged. 
 
 In cutting through a hard stra- 
 tum, or under circumstances where 
 iron pipes could be dispened with, 
 
 this plan of boring a hole would 
 doubtless answer; bnt it is con- 
 ceived that the bore could scarcely 
 be made sufficiently straight to ad- 
 mit of pipes being inserted. It is, 
 however, a much less costly me- 
 thod of executing the work where 
 it can be made to apply, and is well 
 worth attention. 
 
 Well-staircase, a winding staircase of 
 ascent, or descent, to different 
 parts of a building, so called from 
 the walls enclosing it resembling a 
 well, called frequently a geometri- 
 cal staircase. 
 
 Weold, or Weald (Saxon), a forest. 
 
 Wharf, a levelled surface, terrace, or 
 embankment, formed on a river or 
 canal bank, or sea-coast, to facili- 
 tate the landing and embarkation 
 of persons and goods, and protected 
 by an artificial frontage or struc- 
 ture of masonry or other materials. 
 The natural form of banks and 
 coasts, unless defined by masses of 
 rock, is usually shelving or inclined, 
 so that the depth of water is gra- 
 dually reduced, and thus prevents 
 the close approach of floating ves- 
 sels. By the construction of wharf- 
 walls, which are either extended 
 into the deep water, or the founda- 
 tions of which are sunk so as to 
 permit of the subsequent removal 
 of the bank, and thus bring deep 
 water into contact with them, ves- 
 sels are enabled to come close along- 
 side, and thus discharge or receive 
 their cargoes directly from the 
 wharf. Wharf- walls are constructed 
 of various materials, but are always 
 formed with a slope or batter out- 
 wards towards the base, in order to 
 give greater stability to them, and 
 to resist the action of the tide and 
 the waves. Much theory has been 
 expended in attempts to determine 
 the precise forms which should be 
 given to these structures, and, ac- 
 cordingly, some engineers approve 
 of plane-faced walls, while others 
 prefer curved faces ; and another 
 theory has been started to explain 
 that a perfectly vertical face is the 
 
 569 
 
WHA 
 
 WHEEL AND AXLE. 
 
 WHE 
 
 best of all adapted to resist the in- 
 fluence of waves. Whether this 
 position be theoretically correct or 
 not, however, the value of an ex- 
 tended base, in giving stability, is 
 too well known to need demonstra- 
 tion, and derives support from that 
 intuitive kind of feeling which pro- 
 ceeds directly from the evidence of 
 our senses. Adopting the inclined 
 plane face as a good practical one 
 for wharf- walls, the rate of inclina- 
 tion or batter may be determined 
 from 1 in 8 to 1 in 12, that is, with 
 a total divergence from the perpen- 
 dicular of & or Jjj of the total height, 
 being from 1 to H inch, in a foot. 
 The front of the wall, if of masonry, 
 may be protected by a row of sheet- 
 piling, either of timber or iron. In 
 the former case, the piles are driven 
 close together, and bound along 
 the top with a horizontal tie or 
 waling firmly bolted to the piles. 
 If iron piling is used, the piles are 
 driven at intervals of from three 
 to five feet, and cast-iron plates 
 fitted in between them, being se- 
 cured within grooves formed in the 
 sides of the piles. The Brunswick 
 Wharf, at Blackwall, affords a good 
 example of this description of 
 piling. The masonry of the wall 
 is founded upon the piling, the 
 length and closeness of the piles 
 being determined with reference to 
 the nature of the subsoil, and the 
 whole of them are driven to a firm 
 bottom and levelled on the heads, 
 being strongly secured in their po- 
 sition by means of longitudinal and 
 transverse ties or beams, on which 
 the first course of footings was built. 
 The durability of these walls is 
 known to depend greatly upon the 
 kind of mortar or cement used in 
 connecting the masonry or brick- 
 work. Cements known as water- 
 cements, formed with lime which 
 has the property of hardening un- 
 der water, should be preferred to 
 all others. The thickness of the 
 wall must depend upon its height 
 and the nature of the materials be- 
 
 hind it. If these are likely to press 
 severely against the wall, such as 
 clays liable to hold great quantities 
 of water, etc., the thickness of the 
 wall will be required to be greater 
 than if gravel, or other non-reten- 
 tive material, forms the backing. 
 Strong ties of iron should in all 
 cases be secured to the front of the 
 wall, passing through it, and being 
 secured by plates and keys in the 
 front, and extending backward to 
 a considerable distance, and se- 
 cured to a row of piling driven into 
 the solid ground. These land-ties 
 will also considerably assist the 
 wall in resisting the forward pres- 
 sure of the soil behind it. Imme- 
 diately at the back of the wall a 
 firm body of concrete, or at least 
 well-puddled clay, should be in- 
 troduced. Whichever of these is 
 used as a backing, it should be 
 consolidated as much as possible, 
 and it will thus resist the admission 
 of moisture behind the wall which 
 is indispensable to secure its per- 
 manent durability. The concrete 
 should be cast in from a height 
 above its intended position, and 
 allowed to set before it is filled in ; 
 and if clay be substituted, it should 
 be thoroughly well rammed in, and 
 made as solid as possible. 
 
 Wheal. The ancient Cornish called 
 a mine huel, which has been cor- 
 rupted into wheal. 
 
 Wheel and axle. This machine is so 
 named by reason of its consisting 
 of a wheel and cylinders, having a 
 common axis with pivots fixed in 
 its extremities, on which the whole 
 may revolve. This very simple and 
 useful contrivance, although usual- 
 ly designated a second mechanical 
 power, requires the consideration 
 of no other principles than those 
 adduced for the lever ; it is nothing 
 but a lever, having the radius of 
 the wheel for one arm, and that of 
 the cylinder or axle for the other, 
 the fulcrum being the common 
 centre of both. This machine is 
 also termed the ' Perpetual Lever ;' 
 
 R70 
 
WHE 
 
 WHEEL-CUTTING MACHINE 
 
 AVHI 
 
 for since the power and the resist- 
 ance operate respectively at the 
 circumference of a circle revolving 
 about an axis, it is obvious that 
 the rotation must maintain the 
 continuity. 
 
 Wheels, in locomotive engines : the 
 well - known invention for ob- 
 taining a rolling progressive mo- 
 tion. They receive names corre- 
 sponding to the part of the engine 
 or tender they support ; as leading, 
 trailing, etc. Driving wheels vary 
 in size from 4 feet 6 inches up to 
 10 feet diameter. Leading and 
 trailing wheels vary from 3 feet 
 up to 4 feet 6 inches in diameter. 
 Tender wheels are usually about 
 the same size as the leading and 
 trailing wheels of the engines they 
 are attached to. 
 
 Wheel-cutting machine, a machine for 
 cutting out the teeth of wheels. 
 The most perfect machines for 
 shaping the teeth of wheels are 
 those invented by Mr. Lewis, of 
 Manchester, which are adapted for 
 cutting the teeth of spur, bevel, 
 and worm wheels, of either metal 
 or wood. The principal working 
 parts of these machines and the 
 mode of action is as follows : 
 
 Two side-frames have angular 
 ridges from end to end, to fit into 
 corresponding grooves in the bot- 
 tom of a travelling frame : this 
 frame can be adjusted by a screw 
 moved by a hand-wheel at the 
 back of the machine : at the front 
 of the machine is a strong spindle, 
 placed vertically, to carry the work 
 which is fixed on the top of it, and 
 at the lower part is a large worm- 
 wheel moved by a screw, to which 
 is connected a train of three wheels: 
 the sizes of the first and third 
 wheels must be such that half a 
 revolution of a handle, which falls 
 into a notch after each half-revo- 
 lution, shall turn the work so that 
 any point in the pitch-line of it 
 will move through a distance equal 
 to the pitch. To the travelling 
 frame a slide is attached by bolts 
 
 571 
 
 and joints, in such manner that it 
 may be fastened to act vertically, 
 or at an angle in the direction 
 either of the length or breadth of 
 the machine. The cutter, and its 
 wheels for diminishing the speed 
 and pulley for communicating mo- 
 tion to it, are carried by the slide. 
 The cutter is a circular piece of 
 steel notched like a saw, and shaped 
 to fit the spaces between the teeth 
 of the wheel, and is raised or low- 
 ered by a rack at the back of the 
 slide, worked by a pinion and han- 
 dle. The travelling frame and slide 
 being adjusted to the work, and 
 the suitable wheels arranged for 
 turning it the given distance, the 
 machine is set in motion and the 
 revolvingcutter pressed down upon 
 the rim of the wheel by the handle 
 and rack till the space has been 
 cut ; the cutter is then raised, and 
 by giving half a revolution to the 
 handle attached to the worm-wheel 
 apparatus, the spindle and work are 
 turned so that the latter is in pro- 
 per position for the cutter to act 
 again. For a spur-wheel the slide 
 acts vertically, for a bevel- wheel it 
 acts at the requisite angle in the 
 direction of the length, and for a 
 worm-wheel at an angle in the 
 direction of the breadth of the 
 machine. 
 
 Whim, a machine used for raising 
 ores, etc., worked by horses, steam, 
 or water. 
 
 Whim-shaft, in raining, the shaft by 
 which the stuff is drawn out of the 
 mine by the horse or steam whim. 
 
 Whispering gallery, a curvilinear cor- 
 ridor or balcony within the cupola 
 of St. Paul's cathedral, London, 
 and in other ecclesiastical build- 
 ings. 
 
 White Chalk is a well-known native 
 carbonate of lime, used by the 
 artist only as. a crayon, or for 
 tracing his designs; for which pur- 
 pose it is sawed into lengths suited 
 to the port-crayon. White crayons 
 and tracing chalks, to be good, must 
 work and cut free from grit. From 
 
WIC 
 
 WILKIE. 
 
 WIL 
 
 this material both whiting and lime 
 are prepared, and are the bases of 
 many common pigments and co- 
 lours used in distempering, paper- 
 staining, etc. 
 
 Wicker-work, at an early date, was 
 occasionally employed for the roof- 
 ing, if not for the entire construc- 
 tion, of churches. 
 
 Wicket, a small gate or door within, 
 or a part of a massive or larger 
 door or gate for the passage of 
 pedestrians. 
 
 Wilkie (Sir David). The works of the 
 late Sir David Wilkie left by him 
 at his decease cons sted of water- 
 colour drawings, portfolios of 
 studies and sketches, sketches in 
 oil colours and incomplete pictures. 
 There were many works finished : 
 nearly all of them were works done 
 when from home : some in Ireland, 
 some in Spain, most on his journey 
 to the Holy Land. They are proofs 
 of unremitting industry ; nothing 
 escaped him, all that met his eye 
 formed subjects for his pencil, 
 whether a distant landscape, a pipe 
 or a sword, an eastern street, a girl 
 at a window, Mehemet Ali, or a 
 scene near the birthplace of Ho- 
 mer. Proofs indeed these works 
 are of his practice being a work of 
 love ; it cannot but be supposed 
 that all this labour must have been 
 the occupation of his leisure hours 
 as well as his working hours. 
 Well might Sir Robert Peel, at the 
 meeting for erecting a monument 
 to Wilkie, bring into notice such 
 untiring industry. Anything of the 
 slightest interest was committed to 
 paper. Numbers of the subjects 
 would not form finished pictures, 
 nor enter into the composition 
 of pictures, though possibly any 
 might be subservient for such pur- 
 pose ; but seemingly without look- 
 ing forward to any further use, he 
 committed everything to canvas, 
 or rather to paper. Similarly may 
 it be said of Wilkie in his art ; he 
 reduced to design whatever entered 
 his eye, and design came to him by 
 
 nature spontaneously. The collec- 
 tion also contained a number of the 
 works of Fuseli. Fuseli and Wilkie, 
 what a contrast ! The one all imagi- 
 nation, the other all reality. Sin 
 and Death, A Griffin pursuing an 
 Arimaspian, The Nightmare(sketch 
 for), Macbeth and the Witches, The 
 Walpurgis Night, were some of the 
 subjects Fuseli had selected. 
 
 Wilkie's practice does not appear 
 uniformly the same; he varies much 
 in the materials of his studies and 
 sketches. There is a distinction 
 to be remembered between works 
 executed at home and abroad. The 
 facilities in the one case and the 
 difficulties in the other, lead to se- 
 lecting different materials. There 
 is one, 'A Village School :' the heads 
 and figures are all put in with their 
 expressions, butnotfinished. Colour 
 is also put in, but unfinished in the 
 back and foreground ; the canvas 
 is covered, or rather the panel, for 
 though it is, I should say, the size 
 of a half-length, the painting is on 
 a panel, and the ground pure white. 
 There is much humour in the Do- 
 minie, and in the several groups. 
 There is a right good spirit about 
 it, that shows how at home Wilkie 
 was in the subject. For such ex- 
 cellence people don't like to receive 
 his other works. There is much to 
 be said on this question. 
 
 His works are evidences of the 
 great care and neatness of hand in 
 the progress of his pictures. There 
 is nothing to undo or to amend, 
 and only the part that he intends 
 to finish appears touched. There 
 is no experimental uncertain paint- 
 ing put in one day to be expunged 
 another. Wilkie advised Haydon 
 to use dark background colours 
 with economy in an early stage, 
 and he practises his precept, though 
 he puts in freely a dark that in 
 chiaroscuro is to stand as such. 
 
 The other picture is ' Knox ad- 
 ministering the Sacrament :' this 
 too is upon panel, the ground pure 
 white. The heads more perhaps 
 
WIL 
 
 WILKIE. 
 
 WIL 
 
 quite finished. It is less in size ; 
 beside it, is a small rough sketch 
 upon paper of the principal figures ; 
 
 ithe others are uncertain. There 
 is also a smaller sketch in oil made 
 with great precision, the surround- 
 ing groups still not the same as ap- 
 pear in the picture. There is too a 
 study in black chalk of Knox, and 
 two of the principal heads very 
 carefully and effectually drawn. 
 The heads are probably painted 
 from these with nature present as 
 a guide. It appears that Wilkie 
 must have made use of his stu- 
 dies and sketches for painting from, 
 because, as 'in this instance, if he 
 used nature this highly finished 
 chalk study would be useless. 
 Haydon remarked what a strange 
 practice Wilkie had observed in 
 the Knox. On a milk-white panel 
 he had painted in the heads and half- 
 figures into a glaze of asphaltum as 
 it appeared, the MacGuelp just 
 tinged. No other part of the pic- 
 ture was worked upon, a few slight 
 pencil lines only indicating the 
 lower part of the figures in the 
 foreground. The leading part of 
 the picture reminded one of Da 
 Vinci's ' Last Supper.' The back- 
 ground, which was untouched and 
 for which I saw no arrangement in 
 any sketch, was staring him in the 
 face during the time of completing 
 the heads, and from its pure white- 
 ness blinding him while painting. 
 In effect too it was injuring the 
 finished parts, which had a yellow 
 glaze which looked sickly. There 
 is something of this unpleasing 
 effect constantly about Wilkie's 
 painting. It is not from painting 
 into a glaze, I think, that this oc- 
 curs, but from passing a glaze over 
 finished work, for there was a por- 
 tion of the armour in the upper 
 portion of one figure which was 
 free from this stain. The white 
 background could not be for a key; 
 it was very dazzling and disa- 
 greeable next the finished work. 
 There was one hand left, I suppose, 
 
 in dead colouring, for it was quite 
 pallid, though it had a finished look 
 like being worked up in brown anc 
 white. Haydon said, "Oh ! but the 
 next thing he'd go over the back- 
 ground with colour;" and there was 
 more probability, I think, of his 
 completing the figures before such 
 process. Haydon commended 
 highly Wilkie's mode in ' The 
 School ' of getting in the subject : 
 this is what I have before men- 
 tioned and admired. There is 
 much cautious treatment, like the 
 process in water-colours. It has 
 more of the neatness and precision 
 of the Dutch masters than the im- 
 pasto of the Italian. In the cata- 
 logue of his effects connected with 
 'The School,' the following. It is to 
 be remembered there are 36 figures 
 in the composition. No. 84, Study 
 (in chalk) for ' The School.' 150, 
 'Hedge School :' this probably might 
 suggest the work. 1 83,' The School,' 
 group of hands. 184, Do. 185, Do. 
 186, Do. two studies. 303, Sketch 
 (chalk) for ' The School.' 304, Do. 
 385,'The Schoolmaster.' 3 18, Study 
 for the School. 3 19, Do'. Study of 
 hands and a head for the School. 
 ' The School' brought 720 guineas, 
 and was bought by Moon. For the 
 Knox picture the following are in 
 the catalogue : 
 
 60. ' John Knox administering 
 the Sacrament/ in pen and ink, 
 slightly washed. 191. ' John 
 Knox administering the Sacra- 
 ment.' 245. ' Knox presenting the 
 Cup,' study of hands. 246. Do., 
 two hands. 247. Do., gauntlets. 
 248. Do., with the cup and a 
 lady : from same. 249. Do., 
 preaching, and one other. ' The 
 Letter Writer' sold, price 425 
 guineas. ' The Tartar relating the 
 Capture of Acre ' sold for only 
 175 guineas. Both very unfinished, 
 the latter most so. ' The Letter 
 Writer' was very effective and very 
 pretty. It represents a girl con- 
 sulting a letter-writer in the streets 
 of Constantinople : a female 
 
WIL 
 
 WTLKIE. 
 
 WIL 
 
 in the foreground forms the group. 
 The old Turk has his pipe, and an 
 old chest beside him, containing 
 his writing materials, I suppose; 
 a dog lies in one corner. Painted 
 upon panel. In the catalogue was 
 found 446. First sketch of the 
 * Letter Writer,' & tinted drawing ; 
 the colouring was very little. 
 This, I think, was probably the 
 the first whether taken on the 
 spot, or immediately on reach- 
 ing home, is doubtful. There is 
 another sketch at the Royal Aca- 
 demy which may be for the ar- 
 rangement of colour : some parts 
 are in pencil, some in red chalk, 
 and water colour. From this pro- 
 bably the oil painting was taken. 
 580. Study ftf an old chest. This 
 I did not see, but probably this 
 may be for the 'Letter Writer.' 
 Examples of Eastern costume 
 Wilkie brought with him. A male 
 and female lay figure were dressed 
 in them. From Spain too he 
 brought some. Haydon bid for 
 a Spanish cloak. 488. ' Bargain- 
 ing for a Circassian Slave,' a 
 tinted drawing. In this sketch, 
 or rather composition, I recognized 
 the figure of the Circassian slave 
 as that of one who before passed as 
 462. 'A Circassian Lady.' In this 
 way Wilkie may have made figures 
 do duty frequently. 'The Tartar 
 relating the capture of Acre' may 
 have been composed in this way. 
 It is of great interest to trace the 
 history of a great man's works. 
 With this view I examined Wilkie's 
 sketches to trace their history if 
 possible, and his practice. In this 
 way he may have composed the 
 last-mentioned picture. There was 
 his picture of ' Chelsea Pensioners 
 listening to the News of the Battle 
 of Waterloo,' to suggest the sub- 
 ject ; and a great sensation at the 
 time was created by the siege of 
 Acre. Several views of the place 
 he had himself taken. In the 
 East particularly such an event as 
 the siege would form a subject 
 
 of conversation for the common 
 people ; and without seeing the 
 incident he represents there is 
 enough in the following sketches 
 to make up the picture. 447. 'A 
 Barber's Shop, Constantinople.' 
 I mention this, because in the pic- 
 ture is a sketch of a barber shaving 
 a man, with the basin up to his 
 neck. The metal basin is placed 
 with the outside next the throat. 
 It always reminds one of Mam 
 brino's helmet. 482. A ' Turkish 
 Coffee House.' 487. 'A Coffee 
 Shop.' 483. * Interior of a Cafe.' 
 From recollection I should say 
 that 444, ' A Post Rider,' a capital 
 finished sketch, was very like the 
 Tartar relating the news, and per- 
 haps was the man, some of their 
 equipments were the same the 
 position was different. 589 is ' The 
 travelling Tartar, or the Queen's 
 Messenger.' The scene appears in 
 a Turkish coffee-house, where the 
 company are seated, smoking, eat- 
 ing, drinking, being shaved, while 
 the Tartar is relating the news. 
 
 Referring again to nature. In 
 works possessing such truth and 
 nature as Wilkie's, a figure can 
 never successfully be turned to a 
 particular use without such being 
 originally in contemplation of the 
 artist. And again, in composition, 
 a figure borrowed from a sketch 
 will not compose without altera- 
 tion, and with alteration you want 
 nature. Painting from studies 
 that are sketches with design and 
 light shade, where they are taken 
 for one certain intention, and have 
 merely to be copied in colours on 
 canvas, can readily be understood. 
 William of Wykeham. History has 
 only taken care of the fame of one 
 of our early Gothic artists, the 
 architect of Winchester Cathedral, 
 Windsor Castle, and New College, 
 Oxford. He was born 1324, the 
 eighteenth of Edward II. Of 
 Windsor Castle little remains of 
 Wykeham's workmanship, save the 
 Round Tower. 
 
WIL 
 
 WINCH AND AXLE. 
 
 WIN 
 
 Willow wood is of many varieties : it 
 is perhaps the softest and lightest 
 of English woods ; it is planed into 
 chips, and used for many simple 
 purposes. 
 
 Wilson (Richard) was born 1713, in 
 Montgomeryshire. At first he pur- 
 sued portrait painting, hut in his 
 thirty-sixth year, on going to Italy, 
 relinquished that department of art 
 for landscape painting. He found 
 no market for his productions, 
 gradually fell into distress, and 
 was rescued from utter starvation 
 by the salary of librarian of the 
 Royal Academy. Finally he suc- 
 ceeded to a small estate in Wales, 
 which was sufficient for his com- 
 forts, and where he died. Wil- 
 son's landscapes are in general 
 productions of fancy, rather than 
 of existing reality scenes pictured 
 forth by the imagination, rather 
 than transcribed from Nature, 
 yet there is enough of nature in 
 them to please, and enough of 
 what is poetic, to charm the most 
 fastidious fancy. He sometimes 
 painted fac-similes of scenes. 
 
 Wimple, a plaited linen cloth which 
 nuns wear about their necks ; also 
 a flag or streamer. 
 
 IVinch or Wince, in mining, the wheel 
 or axle frequently used to draw 
 water, etc. in a kibble by a rope. 
 
 Winch and Axle, a machine consti- 
 tuting a small windlass, and con- 
 sisting of a cylinder of wood which 
 is capable of turning on its axis 
 between two upright posts of the 
 same material, or between the ends 
 of a cast-iron frame : a lever at 
 one or at each extremity of the 
 .cylinder is attached to an iron axle 
 passing through the latter at right ! 
 angles to its direction, and is fur- 
 nished with a handle, which is 
 parallel to that axle. The name 
 winch is given to a lever or handle 
 of this kind, and the word is sup- 
 posed to be derived from the verb j 
 ffuincher, signifying, in old French, 
 to turn, or bend in a curvilinear j 
 manner. The machine is used to j 
 
 raise a weight vertically, or to 
 draw an object towards it ; for 
 which purposes the object is con- 
 nected with it by a rope or chain 
 which continually passes over the 
 curved surface of the cylinder as 
 the latter is made to turn on its 
 axis by a man acting at the handle. 
 Since the cylinder revolves once 
 while the handle, or the extremity 
 of the lever to which it is attached, 
 is made to describe the circumfer- 
 rence' of a circle, it is evident that 
 the mechanical power of the ma- 
 chine is precisely that of the wheel 
 and axle. When of a simple form, 
 it is employed to raise water from 
 a well, and earth or some other 
 material from the shaft of a small 
 mine ; and one of a complex na- 
 ture is used, by means of a crane, 
 to raise casks or heavy packages 
 from the ground to the upper part 
 of a building. 
 
 When great weights are to be 
 raised, the machine is usually fixed 
 in a frame of cast iron r which is 
 rectangular on the plan, but its 
 extremities or faces have the form 
 of a triangle, or of the letter A. 
 The axle of the cylinder is sup- 
 ported on a horizontal bar at the 
 middle of each end of the frame, 
 and to the cylinder is attached a 
 toothed wheel which turns with it 
 on the common axis : above this 
 wheel, and paralled to the cylinder, 
 is an iron axle which carries a 
 pinion with teeth working in those 
 of the wheel, and causing the latter 
 to revolve, the pinion itself being 
 turned by means of the lever and 
 handle at one or at each extremity 
 of the frame. A machine of this 
 kind is called a crab; and when a 
 weight is to be drawn horizontally 
 or raised above the cylinder, the 
 machine must of course be bolted 
 to the floor or firmly fixed in the 
 ground, in order to prevent it from 
 being moved from its place- In 
 such machines there is generally, 
 at one extremity of the cylinder, a 
 wheel having on its circumference 
 
WIN 
 
 WIND. 
 
 WIN 
 
 teeth like those of a saw ; and a 
 click or catch, which turns freely 
 on a pin, is attached by that pin to 
 the side of the frame in such a 
 manner that it may fall between 
 the teeth. By this contrivance, if 
 the handle should break, or the 
 moving power be taken off while 
 the weight is suspended in the air, 
 the latter is prevented from de- 
 scending. 
 
 Machines of this kind are occa- 
 sionally constructed, which have 
 the power of holding the weight in 
 any part of its ascent or descent 
 without a ratched- wheel and catch. 
 The only disadvantage attending 
 the machine, when compared with 
 an ordinary winch or capstain, is, 
 that it requires a much greater 
 quantity of rope to raise or move 
 the object through any given dis- 
 tance. It was first proposed in 
 Europe by Mr. George Eckhardt, 
 but machines of a like kind have, 
 it is said, long been in use in the 
 East. 
 
 The winch is employed in the 
 common jack, which is used to lift 
 great weights, or to move them 
 through small distances. The 
 handle turns a pinion with teeth, 
 which act on others at the circum- 
 ference of a small wheel ; and on 
 the axle of this is a pinion with 
 teeth, which work in those of a 
 rack-rod. The axles of the wheel 
 and pinions being let into the sides 
 of a case of wood or iron, the re- 
 volution of the wheel produces a 
 rectilinear motion of the rack ; and 
 one end of the case being fixed to the 
 ground, or against an immovable 
 object, the extremity of the rack 
 at the opposite end forces forward 
 the body which is to be displaced. 
 Sometimes, instead of a rack, the 
 machine is furnished with a wheel 
 wliose axle is hollow, and cut in 
 the form of a concave screw : within 
 tWs screw is one of the convex 
 kind, which by the revolution of 
 the wheel and its axle is made to 
 move in the direction of the latter, 
 
 576 
 
 and thus to press before it the ob- 
 ject which is to be removed. This 
 machine has, however, consider- 
 able friction. 
 
 The force exerted by a man in 
 turning a winch vertically, varies 
 according to the position of the 
 lever with respect to the horizon. 
 When the lever, or that part which 
 is perpendicular to the axle, is per- 
 pendicular to the ground, and the 
 handle is at the highest or lowest 
 part of the circle described by the 
 end of the lever, the man either 
 pushes the handle directly from 
 him or pulls it directly towards 
 him ; and in each case he exerts a 
 power which is estimated at 27 or 
 30 Ibs. ; but when the lever is 
 in a horizontal position, the man 
 cithers throws a great portion of his 
 weight on the handle to press it 
 down, or he exerts his muscular 
 force in a direct manner to pull it 
 upwards ; and the force exerted in 
 these positions is estimated at 140 
 or 160 pounds. The force exerted 
 must very evidently have different 
 values between these quantities in 
 other positions of the winch ; and 
 the practice is to cause two men 
 to work at the same time to turn 
 the machine, one being at each 
 extremity of the axle of the cylin- 
 der. The levers of the two winches 
 are placed at right angles to one 
 another; consequently, when one 
 man is pushing or pulling horizon- 
 tally, the other is pressing or pull- 
 ing vertically, and thus the opera- 
 tion of turning goes on with nearly 
 uniform intensity ; the first man 
 working in the least favourable 
 position when the other is working 
 in that which is most so. 
 Wind, instrument for measuring the 
 force and velocity of: a fly (re- 
 semblinnthatofa revclvingventila- 
 tor, or the sails of a wind-mill) is 
 fixed to the small end of the vane of 
 a weathercock so as to be turned 
 with its circular disc to the wind ; 
 and it consequently revolves by the 
 action of the wind with a rapidity 
 
WIN 
 
 WINDOWS. 
 
 WIN 
 
 increasing as the force of the wind 
 increases. The revolutions of the 
 axis of this fly are converted hy a 
 train of toothed wheels and screws 
 into a vertical motion, by which a 
 pencil is carried downwards, touch- 
 ing the surface of a vertical cylin- 
 der the cylinder having the axis- 
 of the weathercock for its axis. 
 As the vertical rod on which the 
 pencil slides is attached to the 
 vane of the weathercock, the point 
 of the compass from which the 
 wind blows is recorded on the 
 sides of the cylinder on which the 
 mark is made ; while the quantity 
 of the wind is represented by the 
 extent of the descent of the pencil. 
 
 Wind beam, in ancient carpentry, a 
 cross-beam used in the principals 
 of many ancient roofs, occupying 
 the situation of the collar in mo- 
 dern king-post roofs. 
 
 Winding, in ships, twisting on an 
 uneven surface. 
 
 Winding engines. In winding engines 
 for drawing coals from a pit, where 
 a given number of strokes are re- 
 quired in drawing a corf, the dia- 
 meter of the roll at the first lift 
 must be ascertained. In this case 
 the engine is supposed to have flat 
 ropes, such as are generally used, 
 and which lie upon each other. To 
 find the diameter of a rope-roll 
 at the first lift, it is necessary to 
 know the depth of the pit, the 
 thickness of the rope, and the 
 number of strokes which the en- 
 gine is intended to make in draw- 
 ing up a corf or curves ; then, the 
 thickness of the rope being known 
 and the number of strokes, the 
 thickness of the ropes upon the 
 roll can be determined, let the dia- 
 meter of the roll be what it may. 
 Suppose the thickness of the rope 
 to be 1 inch, and the number of 
 strokes 10; then the radius of the 
 roll is increased 10 inches, or the 
 diameter is increased 20 inches, 
 whatever the diameter may be. 
 
 Windlass, in mechanics, a machine by 
 which a rope or lace is wrapped 
 
 577 
 
 round a cylinder : in navigation, a 
 horizontal machine of strong tim- 
 ber, used in merchant ships for 
 heaving up the anchor, instead of 
 a capstan. 
 
 Wind-mill, a mill which derives its 
 motive power from the impulse of 
 the wind. The building contain- 
 ing the mill-work is usually lofty, 
 and placed on elevated ground. 
 The machinery consists of a shaft, 
 upon one extremity of which arms 
 radiate at right angles, similarly to 
 the spokes of a wheel : upon these, 
 vanes or sails are set at a small 
 angle (about 22). By this means 
 the wind, blowing directly upon 
 the area occupied by the vanes, 
 acts obliquely upon the whole of 
 them, causing them all to move in 
 a direction transversely to that of 
 the wind. Suitable means are 
 provided for bringing the sails into 
 a position to confront the current 
 of the wind. The motion of the 
 sails is transferred by gearing to 
 any machinery required to be 
 driven, which is most commonly 
 mills for grinding corn. Wind- 
 mills were formerly extensively 
 employed, in Holland, to give mo- 
 tion to pumps for the drainage of 
 land. The power of the wind is 
 uncertain and variable in its inten- 
 sity, and its application as a prime 
 mover for mechanical purposes is 
 consequently limited. 
 
 Windows were almost unknown in 
 the religious and other monumental 
 structures of the Egyptians, Greeks, 
 and Romans, but they constitute 
 an essential and distinguishing 
 feature of the Gothic, to which 
 style they stand in the same rela- 
 tion as Orders do to the temple 
 architecture of antiquity. 
 
 Windows admit of very rich and 
 varied decoration, and those in 
 Beccles church, Suffolk (repre- 
 sented on the opposite page), are 
 beautiful examples. The varied 
 exuberance of fancy displayed in 
 the tracery may possibly be ac- 
 counted for by supposing each to 
 
578 
 
WOOD. 
 
 WOO 
 
 have been the gift of some pious in- 
 dividual, who, while he perpetu- 
 ated his munificence, marked also 
 his taste and ingenuity. 
 
 The practice of window tracery 
 everywhere had its origin in win- 
 dovv -grouping, placing two or three 
 lancet windows beside each other, 
 and one or more foil or rosette 
 windows above and between their 
 heads, in order to fill out the 
 arched cell of the vaulting, which 
 then necessarily gave the whole 
 group an arched outline ; and this 
 was indicated by a general drip- 
 mould or label. It then became 
 desirable to lighten the irregular 
 shaped masses of stone left between 
 the perforations, and this was done 
 by piercing these masses, or span- 
 drils, and reducing the solid frame 
 of each foil or rosette to an equal 
 thickness all round, as if several 
 such frames or rings were packed 
 into one great arched opening, 
 which henceforth was regarded as 
 one window instead of several. 
 (For further illustration, see art. 
 Tracery.} 
 
 Wind-sail, in navigation, a sort of 
 ventilator, consisting of a wide 
 tube of canvas shaped like a fun- 
 nel, to convey a stream of fresh 
 air downwards to the hold and 
 lower deck of a ship. 
 Wing transon, in ships, the upper- 
 most transon of the stern-frame 
 Winze, in mining, a sinking in a lode 
 communicating with one level, for 
 proving the lode or ventilating 
 the drivings. 
 
 Wipers, the cogs of a horizontal wheel. 
 Wood, in its raw state, contains a 
 large amount of water. This water 
 contains more or less soluble mine- 
 rals, and is called sap. By drying 
 wood, a great part, but not all, of 
 this water is evaporated. If wood 
 is dried in a closed vessel, and then 
 exposed to the atmosphere, it 
 quickly absorbs moisture ; but the 
 moisture thus absorbed is much 
 less than the wood originally con- 
 tained. 
 
 The amount of water varies in 
 different kinds of wood, and also 
 varies according to the season. 
 Wood cut in the month of April 
 contains from 10 to 20 per cent, 
 more water than that cut in the 
 month of January. 
 
 The following Table shows the 
 percentage of water in different 
 kinds of wood dried as far as 
 possible in the air: 
 
 Beech 18-6 
 
 Poplar 260 
 
 Sugar and common Maple 27'0 
 
 Ash 28-0 
 
 Birch ....... 30-0 
 
 Oak, red 347 
 
 Oak, white 35 5 
 
 Pine, white 37'0 
 
 Chestnut 38'2 
 
 Pine, red 39'0 
 
 Pine, white 45-5 
 
 Linden 47'1 
 
 Poplar, Italian .... 4-2 
 
 Poplar, black .... 51'8 
 
 Wood cut during the months of 
 December and January is not only 
 more solid, but it will dry faster 
 than at any other period of the 
 year, because the sap by that time 
 lias incorporated a great part of its 
 soluble matter with the woody 
 fibre ; what remains is merely wa- 
 ter. When the sap, during the 
 months of February, March, and 
 April, rises, it partly dissolves the 
 woody fibre ; and the drying of the 
 wood is not only retarded, but the 
 wood is weakened, in consequence 
 of the solid matter thus held in 
 solution. 
 
 The difference in chemical com- 
 position of the woody fire, in 
 most kinds of wood, is but slight, 
 as the following analytical Table 
 shows : 
 
 Hy- Oxy 
 Carbon drogen. gen. 
 Sugar Maple 52'65 5-25 42-10 
 Oak . . . 49-43 6-07 44-50 
 Poplar, black 49-70 6'31 43-99 
 Pine . . . 50-11 6-31 43'58 
 
woo 
 
 WREN. 
 
 WRO 
 
 Wood is generally bought by 
 admeasurement, and its specific 
 gravity is directly in proportion to 
 its amount of carbon, hydrogen, 
 and oxygen. The following Table 
 shows the specific gravity of wood. 
 Water =1000: 
 
 Green. Air-dried. 
 
 Oak, white . . 1-0754 0-7075 
 
 Oak, red . . 1-0494 0-6777 
 
 Poplar . . . 0-9859 0-4873 
 
 Beech . . . 09822 0-5907 
 
 Sugar Maple . 0-9036 6440 
 
 Birch . . . 09012 0-6274 
 
 Pine, red . . 0-9121 05502 
 
 Pine white . . 0-8699 0-4716 
 
 Ebony ... 1-2260 
 
 l<342 
 
 Woolfs engine, a steam-engine so 
 called from its inventor's name, 
 with two combined cylinders of dif- 
 ferent diameter, the eduction pas- 
 sage of the smaller cylinder com- 
 municating with the steam passages 
 of the other ; high-pressure steam 
 being used in the small cylinder, 
 and made to act expansively in the 
 large one, the steam being after- 
 wards condensed in the usual 
 manner. By this arrangement 
 steam is economized, and a con- 
 siderable saving of fuel is effected. 
 
 Work, in mining, ores before they are 
 cleaned and dressed. 
 
 Working big, in mining, signifies 
 sufficiently large for a man to work 
 in. 
 
 Working drawings consist of plans, 
 elevations, sections, and details in 
 full, of the whole, and of all the 
 parts of an edifice, to as large a 
 scale as may be found convenient ; 
 generally made in outline, except- 
 ing the sectional parts, which are 
 mostly shadowed, in order to make 
 them more obvious to the work- 
 man, for whose use these drawings 
 are made. 
 
 Worm-wheel, a wheel having teeth 
 formed to fit into the spiral spaces 
 of a screw, so that the wheel may 
 be turned by the screw. 
 
 Wreath, in heraldry, that which is 
 
 580 
 
 between the mantle and the crest, 
 called also a torce; also a boar's 
 tail, so termed among hunters. 
 
 JTr<?(SirChristopher),born in 1631 
 or 1632. The Monument, by 
 Wren, was begun 1671, and com- 
 pleted 1677. It is of the Doric 
 order, rises from the pavement 202 
 feet. The plinth is 21 feet square, 
 and ornamented with sculpture by 
 Cibber, representing the flames 
 subsiding on the appearance of 
 King Charles ; beneath his horse's 
 feet a figure, meant to personify 
 religious malice, crawls out, vomit- 
 ing fire. The shaft is 15 feet in 
 diameter at the base. The Royal 
 Exchange of London, and Temple 
 Bar, were among his earliest 
 works. St. Paul's was his great 
 work. The Church of St. Peter's, 
 at Rome, had twelve architects, 
 and took 145 years to build; that 
 of St. Paul's was built in thirty- 
 six years, and had but one archi- 
 tect. On the artists of the Roman 
 fabric honours and wealth were 
 showered ; on the architect of 
 St. Paul's the king bestowed 200 
 per annum, and the clerical and 
 lay commissioners harassed him 
 with criticisms, and persecuted 
 him with ridiculous and ground- 
 less charges. 
 
 To describe all Wren's churches 
 would require volumes at least. 
 The church of St. Mary-le-Bow, 
 Cheapside, has been praised for 
 the incomoarable beauty of its 
 spire. The church of St. Stephen's, 
 Walbrook, is reckoned by many 
 the masterpiece of the architect. 
 The church of St. Bride's, Fleet 
 Street, is worthy of being named 
 after that of St. Stephen's, and the 
 many churches in the city of 
 London, St. James's, Westminster, 
 show the greatness of his mind. 
 
 Wrought iron. The chemical differ- 
 ence between cast iron and wrought 
 iron consists principally in the de- 
 gree in which foreign matters is 
 present in each ; which is in larger 
 amount in the former than in the 
 
WRO 
 
 WROUGHT IRON. 
 
 WRO 
 
 latter, this rule is applicable only 
 to a given cast iron, and to the 
 wrought or bar iron which is made 
 from it. There are many cases in 
 which wrought iron contains a 
 larger amount of impurities than 
 cast iron, and still continues mal- 
 leable ; while cast iron of the 
 same composition may be very hard 
 and brittle. Berzelius detected 18 
 per cent, of silex in a certain kind 
 of bar iron, which was still mallea- 
 ble and useful. One-tenth of that 
 amount of silex will make cast iron 
 brittle. The foreign matters gene- 
 rally combined with pig iron are, 
 carbon, silicon, silex, sulphur, phos- 
 phorus, arsenic, zinc, manganese, 
 titanium, chrome, aluminium, mag- 
 nesium, and calcium. Each of these 
 tends to make iron brittle ; there- 
 fore, in converting cast into 
 wrought iron, it is necessary, as 
 far as possible, to remove them. 
 
 The main difference between pig 
 and wrought iron consists in their 
 mechanical structure, or aggregate 
 form. Pig iron is a homogeneous 
 mixture of . impurities and metal. 
 Wrought or bar iron is a mixture 
 of iron more or less pure with a 
 mass of homogeneous impurities, 
 or cinder, the latter filling the cre- 
 vices between the crystals of the 
 iron. Iron being fusible in pro- 
 portion to the carbon it contains, 
 if pig metal is melted, and the cin- 
 der surrounding it exposed to the 
 atmosphere, the carbon will be 
 volatilized in the form of carbonic 
 acid, and iron of greater or less 
 purity will remain. To keep this 
 iron liquid, a higher temperature is 
 required: unless the temperature 
 is raised, it will crystallize. In this 
 state of metamorphosis its infusi- 
 bility will increase, and after the 
 expulsion of the carbon, it will 
 contract into a solid mass in oppo- 
 sition to the highest possible heat. 
 By stirring and mixing the pasty 
 iron, small crystals are formed ; at 
 first, on account of the partial 
 fusion of the iron, in small parti- 
 
 581 
 
 cles; but, as the fusibility dimi- 
 nishes, these particles unite by the 
 force of cohesion ; and the bodies 
 thus formed may, by exposure to a 
 higher heat, be welded together. 
 The mixing of cinder and iron will 
 prevent the latter from forming 
 large crystals : this result, of course, 
 will be more easily prevented by 
 diligent than by tardy manipula- 
 tion. Where the pig iron is of such 
 a nature as to keep liquid while 
 the work goes on slowly, still bet- 
 ter results will be obtained. This 
 process is analogous to that of salt 
 boiling, in which, by stirring the 
 brine, the formation of large crys- 
 tals is prevented. If the crystals 
 of iron thus formed cohere, they 
 produce under the influence of 
 motion, a porous, spongy mass, 
 whose crevices are, if not filled, at 
 least coated, with cinder. If these 
 masses, which are the loups or balls 
 at the puddling furnaces, are shin- 
 gled or squeezed, the crystals of 
 iron will not unite, but form coated 
 cells with a film of cinder, of greater 
 or less thickness, according to the 
 fusibility of the cinder. Iron in a 
 connected form and cinder in sepa- 
 rate cells, are thus blended in o:ae 
 homogeneous mass. The more this 
 iron is stretched, the more it forms 
 fibres. Fibrous bar iron resembles 
 hickory wood, in being a combina- 
 tion of fibres and spaces. In bar j 
 iron, these spaces are filled with 
 cinder. When other circumstances 
 are equal, the strength of the iron 
 will be proportional to the fineness 
 of the fibres. That portion of the 
 iron which is not melted, which 
 crystallizes too fast, or whose pre- 
 mature crystallization cannot be 
 prevented, is in the condition of 
 cast metal, and cannot be con- 
 verted into fibrous wrought iron. 
 In the puddling furnace it is neces- 
 sary to prevent crystallization by 
 manual labour. 
 
 If the characteristic between 
 wrought and pig iron consists only 
 in a well-regulated mechanical mix- 
 
WRO 
 
 \VROtlGHT IRON. 
 
 ture of cinder and iron, fibrous iron 
 should be producible from any cast 
 iron, whether purified or not : this 
 is actually the case. Very fibrous 
 bar iron, which is strong and mal- 
 leable, is made from very inferior 
 cast metal, from which no impurity 
 has been removed. At Hyanges, in 
 France, very inferior metal is con- 
 verted by a cheap and skilful pud- 
 dling process, into a very fibrous 
 bar iron, of great strength and 
 ductility. But this iron is puddled 
 and re-heated at the lowest possi- 
 ble heat ; it is then rolled, and is 
 ready for the market. For hoops, 
 rails, and nails, it is a very useful 
 article, but it is of no use to the 
 blacksmith. Heated to any tem- 
 perature above that of the puddling 
 and re-heating furnaces, it returns 
 to its primitive state, in which con- 
 dition it becomes worse than the 
 cast iron from which it was origi- 
 nally made. None but a very skil- 
 ful blacksmith can weld it ; for, 
 when slightly re-heated, it falls to 
 coarse sandy pieces, or melts like 
 pig iron. That which thus loses 
 its fibrous texture in heating, the 
 smith calls ' burnt iron.' 
 
 The philosophy of the improve- 
 ment of metal consists in the cir- 
 cumstance that a part of its impu- 
 rities which are originally in che- 
 mical combination, are converted 
 into mechanical admixtures. Iron, 
 containing a small amount of car- 
 bon, silicon, or phosphorus, is al- 
 ways more hard and strong than 
 pure iron. Pure iron is quite soft. 
 Impure iron has the property of 
 crystallizing, or being suddenly 
 cooled : the size of these crystals 
 is proportional to the amount of 
 carbon in chemical combination 
 with the iron, in proportion to 
 other matter. Between the crys- 
 tals minute spaces are left, which 
 serve for the absorption of oxygen. 
 By this means, silicon and calcium 
 may be oxidized, but not carbon, 
 phosphorus, and sulphur. The 
 metal improves in quality in pro- 
 
 portion as oxygen finds access to 
 its impurities. 
 
 The absolute cohesion or strength 
 of wrought iron is not dependent 
 upon the degree of purity of the 
 metal, but upon a given mixture of 
 cinder and iron. Pure iron, which 
 is always soft, may be required for 
 various purposes, as in the manu- 
 facture of cast steel ; but, in most 
 cases, an impure but fibrous iron is 
 preferable. In making wrought 
 iron, the main difficulty consists, 
 not in producing fibres in the first 
 stages of the operation, for this 
 may be accomplished by almost 
 every experienced manufacturer, 
 but in retaining these fibres 
 through every subsequent stage of 
 the operation. 
 
 Wrought iron of good quality is 
 silvery white and fibrous ; carbon 
 imparts to it a bluish, and often a 
 gray colour : sulphur, a dark, dead 
 colour, without a tinge of blue ; 
 silicon, phosphorus, and carbon, a 
 bright colour, which is the more 
 beautiful the more the first two 
 elements preponderate. The lustre 
 of iron does not depend principally 
 upon its colour ; for pure iron, al- 
 though silvery white, reflects but 
 little light. A small quantity of 
 carbon in chemical combination, 
 phosphorus, or silicon, increases its 
 brilliancy. Its lustre is diminished 
 by silex, carbon in mechanical ad- 
 mixture, cinder, lime, sulphur, or 
 magnesia. Good iron should ap- 
 pear fresh, somewhat reflex in its 
 fibres, and silky. A dead colour 
 indicates a weak iron, even though 
 it is perfectly white. Dark but 
 very lustrous iron is always supe- 
 rior to that which has a bright co- 
 lour and feeble lustre. Coarse fibres 
 indicate a strong, but, if the iron is 
 dark, an inferior article. AYhere 
 the iron is of a white, bright co- 
 lour they indicate an article of 
 superior quality for sheet iron and 
 boiler-plate, though too soft for 
 railroad iron. For the latter pur- 
 pose, a coarse, fibrous, slightly 
 
ZEB 
 
 YELLOW LAKE. 
 
 YEL 
 
 bluish iron is required. Iron of 
 short fibre is too pure ; it is gene- 
 rally hot-short, and, when cold, not 
 strong. This kind of iron is apt to 
 result from the application of an 
 excess of lime : its weakness is the 
 result of the absence of all impuri- 
 ties. The best qualities of bar iron 
 always contain a small amount of 
 impurity. Steel ceases to be hard 
 and strong, when deprived of the 
 small amount of silicon it contains, 
 or if the silicon is oxidized by re- 
 peated heating. This is the case 
 with bar iron. If deprived of all 
 foreign admixture, it ceases to be 
 
 a strong, tenacious, and beautiful 
 iron, but becomes a pale, soft me- 
 tal, of feeble strength and lustre. 
 Good bar or wrought iron is always 
 fibrous : it loses its fibres neither 
 by heat nor by cold. Time may 
 change its aggregate form ; but its 
 fibrous quality should always be 
 considered the guarantee of its 
 strength. Iron of good quality will 
 bear cold hammering to any ex- 
 tent. A bar an inch square, which 
 cannot be hammered down to a 
 quarter of an inch, on a cold anvil, 
 without showing any traces of 
 splitting, is an inferior iron. 
 
 X. 
 
 Xebec, in navigation, a small three- 
 masted vessel, without a bowsprit, 
 principally used in the Mediter- 
 ranean. 
 
 Xenodochium, a room in a monastery 
 for the reception and entertain- 
 ment of strangers, pilgrims, and 
 the relief of paupers. 
 
 XP. /., the initials of the Greek 
 
 names of Christ ; a monogram, re- 
 presented in paintings and mosaics 
 by the Greek Christians. 
 
 Xylography, the art of engraving on 
 wood. 
 
 Xystos, in ancient architecture, a 
 large portico in the gymnasium, 
 for the accommodation of the 
 wrestlers ; a sheltered walk. 
 
 T. 
 
 Yacht, in navigation, a small ship 
 for carrying passengers. 
 
 Yard, a court enclosed by walls and 
 other buildings; also a measure 
 of 3 feet ; a yard or yerd was an- 
 ciently a spar or rafter in a timber 
 roof. 
 
 Yardland, a certain quantity of land, 
 called, in Saxon, gyrdlander ; in 
 Latin, virgata terrae : in some 
 places it is 20 acres of land, in 
 others 24 or 30. 
 
 Yellow is the first of the primary or. 
 simple colours, nearest in relation 
 to and partaking most of the nature 
 of the neutral white : it is accord- 
 ingly a most advancing colour, of 
 great power in reflecting light. 
 Compounded with the primary red, 
 it constitutes the secondary orange 
 and its relatives, scarlet, etc., and 
 other warm colours. 
 ! Yellow Lake. There are several pig- 
 
 583 
 
 ments of this denomination, vary- 
 ing in colour and appearance, ac- 
 cording to the colouring substances 
 used and modes of preparation. 
 They are usually in the form of 
 drops, and their colours are, in 
 general, bright yellow, very trans- 
 parent, and not liable to change in 
 an impure atmosphere, qualities 
 which would render them very 
 valuable pigments, were -they not 
 soon discoloured and even de- 
 stroyed by the opposite influence 
 of oxygen and light, both in water 
 and oil, in which latter vehicle, 
 like other lakes in general, they 
 are bad dryers, and do not stand 
 the action of white lead or other 
 metallic colours. If used, there- 
 fore, it should be as simple as 
 possible. 
 
 Yellow Ochre, called also Mineral 
 Yelloiv, is a native pigment, found 
 
YEL 
 
 ZIGZAG MOULDING. 
 
 ZIN 
 
 in most countries, and abundantly 
 in our own. It varies considerably 
 in constitution and colour, in which 
 latter particular it is found from a 
 bright but not very vivid yellow to 
 a brown yellow, called spruce ochre, 
 and is always of a warm cast. Its 
 natural variety is much increased 
 by artificial dressing and com- 
 pounding. 
 
 Yellow Orpiment, or Yellow Arsenic, 
 is a sulphurate oxide of arsenic, of 
 a beautiful, bright, and pure yellow 
 colour, not extremely durable in 
 water, and less so in oil. In tint 
 with white lead, it is soon de- 
 
 stroyed. It is not subject to dis- 
 coloration in impure air. 
 Yew. The yew-tree is common in 
 Spain, Italy, and England, and is 
 indigenous to Nottinghamshire. 
 The tree is not large, and the wood 
 is of a pale yellowish-red colour, 
 handsomely striped, and often 
 dotted like amboyna. It has been 
 long famed for the construction of 
 bows, and is still so employed. 
 The English species is a hard, 
 tough, and durable wood, and lives 
 to a great age. It is also used for 
 the making of chairs, the handles 
 of articles of furniture, etc. 
 
 z. 
 
 Zebra wood is the produce of the 
 Brazils and Rio Janeiro ; it is sent 
 in logs and planks as large as 
 24 inches. The colour is orange- 
 brown and dark-brown variously 
 mixed. Its beautiful appearance 
 fits it for cabinet-work and turnery. 
 
 Zero, the commencement of a scale 
 marked 0, or nothing. It usually 
 denotes the point from which the 
 scale of a thermometer is gradu- 
 ated. 
 
 Zeta, presumed to be a room over 
 the porch of a Christian church. 
 
 Zigzag, a moulding by lines arranged 
 in the manner of the heraldic 
 chevron. Zigzag is found fre- 
 quently used in Norman and An- 
 glo-Norman architecture. Very 
 many beautiful specimens of this 
 ornament exist in doors and win- 
 dows of the Anglo-Norman Gothic 
 in England. (See Doors, and the 
 Frontispiece for an early speci- 
 men.) 
 
 Zinc. This metal exists in abundance, 
 and is employed for many pur- 
 poses. It is commonly combined 
 with sulphur in zinc blende, and 
 with carbonic acid in the mineral 
 calamine, which is the most valu- 
 able of all its ores. Zinc may be 
 obtained pure by redistilling in a 
 porcelain retort, which is sold in 
 commerce. It is obtained from the 
 
 584 
 
 ores as follows : they are first 
 washed and mixed with powdered 
 coke or charcoal, are distilled from 
 an earthern close vessel, with an 
 iron tube passing through its 
 bottom, the upper end of which is 
 open, and the lower end entering a 
 vessel of water. At a bright red 
 heat zinc votalizes, and is con- 
 densed in the water, gases passing 
 off along with it. It is a bluish- 
 white metal, which slowly tarnishes 
 in the air. It is brittle at ordinary 
 temperatures, but at about 300 it 
 is malleable, and may be rolled or 
 hammered into sheets, and retains 
 its ductility when cold. At 400 
 it may be reduced to powder : it 
 melts at 773. 
 
 Zinc white is an oxide of zinc which 
 has been more celebrated as a pig- 
 ment than used, being perfectly 
 durable in water and oil, but want- 
 ing the body and brightness of fine 
 white leads in oil ; while, in water, 
 constant or barytic white and pearl 
 white are superior to it in colour, 
 and equal in durability. Never- 
 theless, zinc white is valuable as 
 far as its powers extend in painting, 
 on account of its durability both in 
 oil and water, and its innocence 
 with regard to health ; and, when 
 duly and skilfully prepared, the co- 
 lour and body of this pigment are 
 
ELECTRIC TELEGRAPH. 
 
 sufficient to qualify it for a general 
 use upon the palette, although the 
 pure white of lead must merit a 
 preference in oil. 
 
 Zocle, to name given to a low, plain, 
 square member or plinth support- 
 ing a column. 
 
 Zoophorus, in architecture, a part 
 
 between the architraves and cor- 
 nice, so called on account or the 
 ornaments carved on it, among 
 which are the figures of animals. 
 Zyghyr, or Sigger, in mining. When 
 a slow stream of water issues 
 through a cranny, it is said to 
 sigger, or zyghyr. 
 
 ADDENDA. 
 ELECTRIC TELEGRAPH. 
 
 Electric Telegraph. The employment 
 of electricity in the transmission of 
 intelligence originated at an early 
 period of the history of electrical 
 science. Plans to this effect had 
 been brought before the public ; 
 but all wanted a simplicity of prin- 
 ciple and of construction. In 
 1837, Messrs. Cooke and Wheat- 
 stone obtained their first patent for 
 an electric telegraph, applicable to 
 general purposes. This patent has 
 been subsequently followed at short 
 intervals by others, in which the 
 invention has been gradually 
 brought to its present form ; the 
 principles originally employed have 
 been progressively rendered more 
 varied and general in their ap- 
 plication, and the apparatus more 
 simple in its details. By these 
 improvements the number of wires 
 necessary for the conveyance of 
 intelligence has been reduced, and 
 the construction has been rendered 
 cheaper and more perfect. 
 
 The electric telegraph involves 
 in its construction two essential 
 principles. First, that a magnetized 
 needle, which is free to rotate 
 about its centre, being brought 
 near to a wire, through which an 
 electric current is passing, has a 
 tendency to place itself at right 
 angles to that wire ; the direction 
 of its motion following a certain 
 invariable law. This fact was the 
 discovery of Prof. (Ersted, of Co- 
 penhagen, in 1819. Secondly, that 
 a piece of soft iron, not being per- 
 
 585 
 
 manently magnetic, is rendered 
 temporarily so during the trans- 
 mission of an electric current along 
 a wire coiled spirally around it. 
 
 The figures to which reference 
 is here made, in the brief descrip- 
 tion of the apparatus, are, 1. A 
 view of the interior of the single- 
 needle instrument, showing the 
 position of the coil and of the 
 battery connections. A vertical 
 section of the same, through the 
 coil and handle. 3. The handle 
 or key, in the position for giving a 
 signal, part being removed, to ren- 
 der the battery connections more 
 distinct. 4. Plan of the same. The 
 double-needle instrument diffe-s 
 from the single-needle only in the 
 duplication of all the parts. 
 
 The coil A, figs. 1 and 2, consists 
 of a light hollow frame of brass or 
 wood, around which are wound, in 
 two portions, about 200 yards of 
 fine copper wire, covered with silk 
 or cotton. This length of wire 
 renders the indications of the nee- 
 dle distinct and prompt, even with 
 a low-battery power, or when form- 
 ing part of a very extended circuit. 
 The resistance which would be of- 
 fered by the fine wire of the coil 
 (its diameter being about y^th of 
 an inch) to the passage of a current 
 of electricity, derived from an or- 
 dinary battery of a few cells only, 
 is overcome by using a battery ar- 
 rangement of considerable inten- 
 sity, but which developes the elec- 
 trical fluid only in small quantity. 
 
ELECTRIC TELEGRAPH. 
 
ELECTRIC TELEGRAPH. 
 
 Or, speaking rather more correctly, 
 we should say, that the electro- 
 motive resistance, both of the bat- 
 tery and also of the ordinary circuit, 
 being very considerable, the intro- 
 duction of the resistance of the 
 coil into the latter produces but 
 little influence upon the transmis- 
 sion of the current. Within the 
 brass frame, and therefore interior 
 to the coils of wire, is suspended a 
 magnetic needle, upon a horizontal 
 axis b, which passes across the 
 middle of the frame, and turns on 
 fine pivots at the back and front of 
 the coil. In front of the frame and 
 of the dial of the instrument is 
 fixed on the same axis b, a second 
 needle having its poles oppositely 
 placed to those of the first. This 
 outer needle serves as the indicator 
 or pointer, by which the signals 
 are made, and at the same time is 
 acted upon by the coil, though in 
 a less degree than the inner needle. 
 The combination of the two needles 
 being thus rendered astatic, it is 
 necessary to give a slight prepon- 
 derance to their'lower ends, in or- 
 der that they may recover their 
 vertical position, after having been 
 deflected ; and the action of gravity 
 has been found more effectual, in 
 bringing the needle to rest without 
 oscillations, than either springs ap- 
 plied at the sides, or the directive 
 influence of permanent magnets. 
 With the coil and needles thus ar- 
 ranged, it is evident that signals 
 may be given by the combination 
 of successive deflections to one side 
 or the other ; the extent of such 
 deflections being limited to any 
 degree that may be found con- 
 venient, either by pins fixed on the 
 dial of the instrument, or by stops 
 placed at the sides of the brass 
 frame of the coil. In fact, all that 
 is necessary for rendering these 
 movements of the needle available 
 for the transmission of intelligence, 
 is a contrivance for reversing with 
 ease and rapidity the connection of 
 the battery with the ends of the 
 
 587 
 
 two conducting wires. This expe- 
 dient is provided by the handle or 
 key of the instrument. 
 
 The conductor through which 
 the electrical current is to circulate 
 must be absolutely complete in all 
 parts. It is not necessary that the 
 material of the circuit be the same 
 throughout, but only that its con- 
 ductibility be maintained from the 
 one pole of the battery to the 
 other ; the slightest want of con- 
 tinuity of the conducting matter, 
 at any part of the circuit, being 
 fatal to the passage of the fluid. 
 So long as the wires for telegra- 
 phic purposes were extended be- 
 tween the two points of communi- 
 cation, by being laid within tubes 
 buried in the earth, a second wire 
 was requisite to enable the current 
 to return from the distant station 
 to the point whence it set out. It 
 was well known that the earth 
 itself afforded such a means of 
 return; but the insulation of the 
 wires in the tubes from the earth 
 could not be rendered sufficiently 
 perfect to make the use of the 
 earth, as a portion of the circuit, 
 either prudent or desirable. Wh^n, 
 however, the wires were suspended 
 in the air, according to Mr. Cooke's 
 patent of 1842, the earth was ad- 
 vantageously employed as half the 
 circuit. All that was found neces- 
 sary, was to connect the extreme 
 ends of the conducting wire with 
 plates of copper or other metal of 
 two or three feet of surface, buried 
 at some depth in the ground ; or 
 with any system of gas or water- 
 pipes, which might afford a con- 
 tinuous metallic path for the fluid 
 to the earth. In either case, the 
 depth of the connection beneath 
 the surface must be sufficient to 
 ensure certain contact with moist 
 earth or with water, provided 
 that this latter be not confined 
 within any cistern or reservoir. 
 When all these precautions have 
 been taken, the passage of electri- 
 city is readily effected, the earth 
 
ELECTRIC TELEGRAPH. 
 
 /<" 
 
 -SSfnV- 
 
 588 
 
ELECTRIC TELEGRAPH. 
 
 appearing to offer little or no re- 
 sistance to its progress. Accord- 
 ing to the law established by Ohm, 
 the resistance of any conductor 
 varies directly as its length, and in- 
 versely at its sectional area. The 
 earth may evidently be regarded 
 as a conductor, of which the dia- 
 meter is infinite, compared with its 
 length, and we might therefore be 
 led to expect the result mentioned 
 above. 
 
 To return, however, to the de- 
 scription of the apparatus, the key 
 or handle by means of which the 
 connection of the battery is effected 
 and varied, consists of a cylinder, 
 in which is a middle zone, e, of 
 hard wood or ivory, while the ends 
 are of metal. One of these ends, c, 
 extending through the case in 
 front, forms the actual handle ; 
 while the other, d, is turned down 
 to a shoulder and forms a pivot, 
 which rests in a brass collar, p. 
 The end d carries a steel pin, f, 
 projecting upward, and c, a similar 
 pin g, directed downward. The 
 battery being connected with the 
 terminals z and c, and thence by 
 the brass strips k and m, of which 
 the extremities rest as springs on 
 the metallic ends of the cylinder, 
 may in fact be considered as having 
 its poles at the two pins, /and g, 
 which are fixed in those ends. Two 
 springs, h and h' t are fixed by 
 broad feet to the base of the in- 
 strument, and rest by their upper 
 extremities on two studs or points 
 projecting from a brass rod, i, 
 screwed into the case in front. 
 These springs form the circuit be- 
 tween the terminal /I, with which 
 one end of the conducting wire is 
 connected, and I 4. Between this 
 latter terminal and the external 
 connection, I 2, the coil itself, and 
 the brass strip extending from / 3 
 to I 2, are interposed. When a 
 signal is being sent through the 
 instrument (supposed to hold the 
 place of No. 2 in fig. 5), the cur- 
 rent from No. 1 being considered 
 
 589 2 c 
 
 to enter from the long wire on the 
 line, by the terminal / 2, passes 
 along the brass strip to the terminal 
 / 3, thence through the coil to / 4 ; 
 then to the spring h, across the 
 pin i, down the spring h', and to 
 the terminal / 1 in connection with 
 the wire leaving the station. Were 
 the instrument in question situated 
 as No. 1 or No. 3, it will be seen 
 that one of the terminals, 1 1 or 1 2, 
 according to its position, would be 
 joined to the wire coming from the 
 earth-plate. 
 
 When a signal is to be given by 
 the instrument, the handle being 
 turned as in figs. 3 and 4, one 
 battery-pin, f, is brought in con- 
 tact with the spring h', which is 
 bent back and released from its 
 contact with i, while the other 
 battery-pin g, is pressed against the 
 foot of the other spring h, which at 
 this part is turned up to act as a 
 stop. The current being then sup- 
 posed to start from the pole/, pro- 
 ceeds down the spring h', to the 
 coil and terminal / 2, as before ; 
 thence along the line through the 
 other instruments, and into the 
 earth at the further extremity of 
 the line. Re-ascending from the 
 earth by the wire connected with 
 the terminal I 1, it gains the foot 
 of the spring h, with which the 
 second battery pole g, is in con- 
 tact. It will be seen that the 
 direction of the current is different, 
 according as the key is turned to 
 the right or left. The position of 
 the battery wires is such, that the 
 needle shall be deflected in paral- 
 lelism to the handle. A comparison 
 of fig. 5, in which three instruments 
 are shown in series, with the 
 figures 1, 2, 3, and 4, will render 
 the method of connection, both of 
 the two terminal and of the inter- 
 mediate instruments, sufficiently 
 obvious. The wires on entering a 
 station are designated as ( up' or 
 ' down' wires, according to the 
 portion of the line from which they 
 come. Care must be, of course, 
 
ELECTRIC TELEGRAPH. 
 
 Fig. 6. 
 
 D- 
 
 g> 
 
 Fig. 11. 
 
 Fig. 12. 
 
 Fig. 12. 
 
ELECTRIC TELEGRAPH. 
 
 taken that all the instruments in 
 one series are similarly joined to 
 the up and down wires, so that the 
 course of the current may be alike 
 in all. At the extreme ' up sta- 
 tion' the earth connection becomes 
 the ' up wire,' and at the opposite 
 terminus it takes the place of the 
 ' down wire.' 
 
 The electric fluid is represented 
 as starting from one pole of the bat- 
 tery only, and, after traversing the 
 circuit, returning to the other pole. 
 It is, however, more consonant 
 with the theories deduced from the 
 observation of electrical pheno- 
 mena, to suppose that force is 
 developed equally at both poles of 
 the battery. 
 
 The second principle is that of 
 the temporary magnetization of 
 soft iron by the electric current, 
 applied for the purpose of sounding 
 an alarum at a distant station, in 
 order to summon the attendant to 
 his instrument. The same princi- 
 ple has been employed from an 
 early period of the invention, both 
 by Mr. Cooke and by Prof. Wheat- 
 stone, to transmit visible signals by 
 causing the rotation of a disc, 
 bearing letters or figures, or of a 
 hand or index pointing to charac- 
 ters on a fixed dial; but in Eng- 
 land the needle telegraph has been 
 universally adopted, in preference 
 to any other form. Many improve- 
 ments have, however, been effected 
 within the last few years by Prof. 
 Wheatstone in the construction of 
 the mechanical telegraph, as it has 
 been named in contradistinction to 
 the needle instrument. The same 
 gentleman has also succeeded in 
 substituting for the voltaic battery 
 in the working of this telegraph, 
 the magneto-electric machine, in 
 which the current is derived by 
 induction from a permanent mag- 
 net. The improvement which was 
 effected by this adoption of a source 
 of power, alike energetic and un- 
 a'terable, will be immediately per- 
 ceived. Telegraphs on this plan of 
 
 construction have been erected in 
 Prussia and France, and, were it 
 not for some very marked advan- 
 tages connected with the use of 
 the ueedle signals, they could 
 hardly fail to become general. 
 
 The ringing of the alarum was 
 originally effected by the direct 
 action x>f the voltaic magnet upon 
 the hammer of the bell ; but this 
 method has been long superseded. 
 The apparatus generally in use for 
 this purpose is shown in a front 
 and back view in figs. 11 and 13, 
 and in a side view at figure 12. 
 An electro-magnet is formed by 
 coiling fine insulated copper wire 
 around two cylinders of very soft 
 pure iron. These coils, c c, are 
 then connected by two of their 
 ends, in such a manner that the 
 direction in which the wire is 
 wound about the iron cores may 
 be alike in both. The iron cylin- 
 ders are joined together at one end 
 by a cross-piece d, likewise of soft 
 iron, so that the whole then forms 
 a horse-shoe magnet, having how- 
 ever its two sides parallel. In front 
 of the free ends or poles of this 
 magnet, which is fixed on the top 
 of the plates of the alarum, an arm- 
 ature a, of soft iron, is placed at 
 such a distance that it may be 
 strongly attracted by the electro- 
 magnet when the circuit is com- 
 pleted through its coils. The arm- 
 ature moves on an arbor, upon 
 which a detent or catch e, is fast- 
 ened, and so arranged that it is 
 disengaged from a small fly u, when- 
 ever the attraction takes place. 
 This disengagement allows a train 
 of clock-work, impelled by a spring 
 or weight, to run down, and by the 
 action of a scape-wheel and pal- 
 lets, seen in fig. 11, a hammer, h, 
 rapidly strikes a small bell g. Im- 
 mediately, however, that the cur- 
 rent ceases to flow through the 
 coils, the iron within them loses 
 its magnetism, a small re-acting 
 spring, s, draws back the armature, 
 and interposes the detent so as to ; 
 
 591 
 
ELECTRIC TELEGRAPH. 
 
 J 
 
 LONDON. 
 
 Stratford. 
 Lea Bridge. 
 
 Tottenham. 
 Marsh Lane. 
 Edmonton. 
 Ponder's End. 
 
 Waltham. 
 
 BROX- \ 
 BOURNE. / 
 
 Roydon. - 
 
 Burnt Mill. 
 Harrow. 
 
 Sawbridgeworth. 
 Stortford. 
 
 Stanstead. 
 Elsenham. 
 Newport. 
 Wendon. 
 
 Chesterford. 
 Whittlesford. 
 Shelf ord. 
 
 CAMBRIDGE. 
 
 Waterbeach. 
 
 Ely. 
 
 Mildenhall road. 
 Lakenheath. 
 
 BRANDON, 
 
 .ft Junction with 
 *^^ Norfolk Railwav. 
 
 592 
 
ELECTRIC TELEGRAPH. 
 
 stop the clockwork. It is neces- 
 sary that the iron of the magnet 
 should be quite pure and soft, as 
 otherwise the magnetization is to 
 a greater or less degree permanent ; 
 and this may be the case to such 
 an extent as to keep the armature 
 attracted, even after the cessation 
 of the electric current. The bell 
 would then continue to ring until 
 the disengagement of the armature 
 were caused by the hand of the 
 attendant. 
 
 The bell or alarum may form 
 part of the telegraphic system in 
 two modes. In the first, and most 
 economical, its coil is made to form 
 part of the circuit of one of the 
 needle wires, in conjunction with 
 a key or rheotome. In the second 
 and more complete method of in- 
 troducing the alarum, a distinct 
 wire is employed for it, in the 
 course of which the magnet coils 
 at the several stations are inter- 
 posed. A key of different con- 
 struction (shown in section at fig. 
 14) is then employed. The body 
 is of brass, but two stout wires, z 
 and c, are conducted through ivory 
 tubes, and terminated in studs, pp, 
 at the top and bottom of the cylin- 
 drical end of the key ; the wires 
 and studs being insulated from each 
 other, and from the key, by the 
 ivory in which they are fixed. The 
 collar t' t and nut, t, serve to se- 
 cure the key to the side of the case 
 or box in which it is placed, the 
 former, t 1 , also containing the 
 spring, by which, after use, the 
 key is brought back to its quiescent 
 position. Two springs, not shown 
 in the figure, then rest against the 
 metal of the end, one on each side, 
 and while in this position, merely 
 complete, by the intervening metal, 
 the circuit of the bell-wire which 
 is connected to the foot of one 
 spring directly, and to the foot of 
 the other by the intervention of 
 the bell coil. The wires, z and c, 
 are joined to the two poles of the 
 battery by pieces of thin wire.which 
 
 593 
 
 will offer no resistance to the revo- 
 lution of the key on its axis. In 
 the quiescent position, the course 
 of a current entering from a distant 
 station would be, from the line- 
 wire on one side, along one spring, 
 across the body of the key to the 
 other spring, and thence through 
 the alarum coil to the continuation 
 of the line-wire, or to the earth 
 connection. When, however, the 
 bell is to be rung to call the atten- 
 tion of the clerk at another station, 
 the key is for a moment turned one- 
 quarter round. This brings the 
 battery studs, p p, into the circuit, 
 instead of the body of the key; 
 and the current then proceeds from 
 the battery of the ringing station 
 by the spring and wire on one side, 
 passes along the line, and returns 
 by the earth through the other 
 spring again to the battery. 
 
 The relative advantages of these 
 two methods may be briefly stated, 
 The first has the recommendation 
 of economy, inasmuch as no addi- 
 tional wire is necessary for the 
 bell. If, however, the clerk 4 n 
 charge of an instrument, after 
 turning off his bell preparatory to 
 sending or transmitting intelli- 
 gence, should chance to leave bis 
 telegraph, and omit to turn the 
 key so as to replace the bell in the 
 circuit, no means are left to other 
 stations of calling his attention, 
 except by working the needles, 
 with the chance of their movement 
 meeting his eye. By the adoption 
 of the second method, the expense 
 of an additional wire is incurred, 
 but the bells at all stations are 
 constantly in a position to be rung 
 if necessary. In addition to this, 
 it may be remarked, that by keep- 
 ing the bell and needles distinct 
 from each other, no derangement 
 of the one is to be feared from 
 injury to or derangement in the 
 other. 
 
 Mr. Cooke's first plan, in the 
 extension of the conducting wires 
 between distant points, was, as has 
 
. ELECTRIC TELEGRAPH. 
 
 been already stated, to cover each 
 wire with cotton or silk, and then 
 with pitch, caoutchouc, resin, or 
 other non-conducting material, and 
 to enclose them, thus protected, in 
 tubes or pipes of wood, iron, or 
 earthenware. Excepting in those 
 localities where the suspension of 
 wires is impracticable, as in streets, 
 towns, or on public roads, the early 
 plan has given place to more re- 
 cent inventions. In 1842, a patent 
 was obtained by Mr. Cooke, for a 
 means of suspending and insulating 
 the wires in the air, and the me- 
 thod described in his specification 
 has been since adhered to, with 
 little variation. The wires are 
 generally of iron, which is galva- 
 nized, to protect it from the action 
 of the atmosphere. They are of 
 about one-sixth of an inch in dia- 
 meter, corresponding to No. 8 of 
 the wire-gauge. Being obtained 
 in as great lengths as possible in 
 the first place, successive pieces 
 are welded together, until a coil of 
 about 440 yards is formed. These 
 rings or bundles weigh about 120 
 pounds each. The wires are sus- 
 pended on the line, from stout 
 squared posts or standards, of 
 Dantzic or Memel timber. At 
 each quarter-mile, a stronger post 
 is fixed, from which the succeeding 
 lengths of wire on either side are 
 strained or tightened up. Inter- 
 mediate to these principal posts, 
 are placed smaller standards at 
 from 45 to 55 yards asunder, for 
 the pnrpose of supporting the wires. 
 The straining apparatus is very 
 simple, consisting merely of a reel 
 or pulley, turning between two 
 cheeks of cast iron, and carrying 
 upon its axis a ratchet-wheel, into 
 the teeth of which a click or catch 
 falls. These winding heads, shown 
 at r r, figs. 7 and 9, are connected 
 through the post by a bolt of 
 wrought iron, b, tapped into each 
 head. This bolt not only bears 
 the strain of the wires, but also 
 forms the metallic communication 
 
 between their ends wound on the 
 two reels. In order to insulate 
 the bolt from the wood of the post 
 the hole in this latter is bored very 
 large, and collars of earthenware, 
 t #> are inserted at each side, in 
 which the bolt rests, and against 
 their outer surfaces the winding 
 heads are screwed up tight. Fig. 9 
 is a section through the post and 
 collar, showing this arrangement. 
 Fig. 7 is a front, and 8 a side view 
 of the head of a straining or quarter- 
 post. The wires are usually 
 arranged in two vertical planes, at 
 the back and front of the standards, 
 or intermediate posts. They are 
 not strained at each quarter-mile, 
 but at intervals of half a mile al- 
 ternately ; those in the front plane 
 at one post, and those in the back 
 plane at the next. The standards 
 or supporting posts have merely to 
 sustain the weight of the wires 
 without relation to their tension. 
 They have on each side two stout 
 arms of oak or ash, secured by 
 bolts, passing from one to the 
 other, and resting in collars of 
 earthenware, x #, where they pass 
 through the standard. The wires 
 pass through pieces of earthen- 
 ware, of a double cone shape, e e, 
 fastened to the outside of the arms 
 by staples or clips, having a nut 
 and screw at the end. These staples 
 embrace the cones at a groove 
 in the middle of their length. An 
 arm similar to those on the stand- 
 ards is fixed to the back and front 
 of each post alternately, to support 
 that plane of wires which passes 
 without being strained. The in- 
 sulating earthenwares between the 
 arm and post, y y, are, however, 
 different in shape from those used 
 with the standard arras, as greater 
 length is requisite. 
 
 In passing through tunnels and 
 bridges, or in front of walls or 
 buildings, where posts cannot be 
 conveniently fixed in the ground, 
 the wires are supported on octago- 
 nal standards of oak or ash, fixed 
 
 594 
 
ELECTRIC TELEGRAPH. 
 
 at about six inches from the wall 
 by holdfasts of galvanized iron. 
 
 The following are the principal 
 dimensions of the posts and poles :> 
 
 LENGTH. 
 
 AT BASE. 
 
 AT TOP. 
 
 Posts. 
 
 Standards. 
 
 Posts. 
 
 Standards. 
 
 ft. 
 
 18 
 22 
 
 28 
 
 in. in. 
 9x8 
 10 x 8 
 11 x 10 
 
 in. in. 
 6x6 
 
 7 x 6 
 8 x 7 
 
 in. in. 
 7 x 6 
 do. 
 do. 
 
 in. in. 
 5* x 4* 
 do. 
 do. 
 
 The batteries employed are in 
 the form of a Wollaston's trough, 
 in which are arranged plates of 
 copper and amalgamated zinc, each 
 cell being filled with dry and 
 clean sand. When about to be 
 used, the sand is just moistened 
 with dilute sulphuric acid. These 
 batteries are singularly constant, 
 having been known to remain in 
 action during a period of from two 
 to five months, with only the occa- 
 sional addition of a little more acid 
 solution, to supply the waste by 
 evaporation and saturation. The 
 effect of the sand appears to be, 
 the prevention of too rapid an ac- 
 tion, and, at the same time, the 
 separation of the sulphates of cop- 
 per and zinc. No copper is there- 
 fore deposited on the zinc plate. 
 The points necessary to be observed 
 are the perfect amalgamation of the 
 zinc, the absolute freedom of the 
 sand from lime or other alkali, 
 from carbonates or muriates, and 
 the purity of the sulphuric acid. 
 The zinc is about | or ^ of an 
 inch thick, and is in pieces of 
 4 inches by 3 inches. These 
 plates will last with care for five 
 or six months in almost constant 
 action. A battery series of from 
 12 to 60 pairs is required, according 
 to the length and nature of the 
 line and the number of instru- 
 ments in connection. 
 
 Six wires are extended along the 
 whole length of railway, of which 
 the upper pair are used with a spe- 
 
 verbai communication, between 
 the main stations, which are Nor- 
 wich, Brundall, Reedham, and Yar- 
 mouth. Each of the other four 
 wires includes at every station a 
 coil and single needle. On the 
 dials connected with the first wire 
 of these four, is engraved the name 
 Norwich at all the stations ; with 
 the second, that of Brundall, with 
 the third Reedham, and with the 
 fourth Yarmouth. The distinct 
 telegraphic system belonging to 
 each station has, therefore, its re- 
 presentative at all the other sta- 
 tions. Each needle or pointer re- 
 presents the state of the portion of 
 line under the control of the sta- 
 tion the name of which it bears 
 The alarum of each instrument is 
 connected only with the wire of 
 its own station, so that on moving 
 either of the needles, the alarum 
 will be rung at the place corre- 
 sponding to the name of the needle 
 but at no other point, although th< 
 movement of the pointer will b 
 visible throughout. 
 
 The electric telegraph is no\v 
 the chief mode oftransmi tting al 1 
 the news of the Government, an< 
 the important correspondence o 
 merchants and of the public gene 
 rally. Its influence is now all-im 
 portant; its extension to the several 
 civilized and commercial countries 
 across the seas, by means of the sub 
 marine cable, is one of the grea 
 aims of science in the present day 
 
RENAISSANCE. 
 
 RENAISSANCE. This term is applied 
 to a style which arose in all the 
 arts of design, from the introduc- 
 tion of antique features, consequent 
 on the revival of classical learning, 
 and the admiration of everything 
 classical after the fall of the Gothic 
 system. 
 
 In Italy, where the arts had 
 never become thoroughly Gothic, 
 the renaissance of classical taste 
 commenced as early as the 13th cen- 
 tury, but in the rest of Europe the 
 Gothic had then hardly arrived at 
 its complete development, or had 
 hardly begun to display its lux- 
 uriance ; and two centuries were 
 required to explore its capabilities, 
 to work out its resources in all their 
 wondrous variety, and to push on its 
 suggestions so far in complication 
 and absurdity, as to render a change 
 of style necessary; and accordingly 
 the arts of Germany, the Nether- 
 lands, France, and England, were 
 not ripe for this change, called the 
 'renaissance,' till the end of the 
 15th or beginning of the 16th cen- 
 tury ; i. e. not till after the inven- 
 tion of printing, the great change 
 of society resulting from which 
 rendered easy the introduction of 
 classic taste into these countries. 
 
 In architecture, renaissance of 
 classical forms and principles first 
 distinctly shows itself in the works 
 of Brunelleschi, the great Floren- 
 tine architect, who lived from 
 1375 to 1444. His most famous 
 work, the cupola of the cathedral, 
 exhibits a bold emancipation from 
 Gothic complexity, and return to 
 classic simplicity. Contemporary 
 wereMichelozzo, and L. B. Alberti, 
 the first modern writer on the art. 
 They were succeeded by Cronaca 
 and Bramante, the latter of whom 
 re-introduced detached colonnades 
 and hanging architraves. His 
 successor, Michael Angelo, with his 
 genius for seizing whatever was 
 
 grand rather than beautiful, re- 
 turned (in the Capitoline Museum) 
 to the classic simplicity of a single 
 order, and an entablature unbroken 
 from corner to corner: the re- 
 naissance was thus complete. San- 
 tnicheli of Verona (1484-1549) 
 originated the fanciful and luxuri- 
 ous school which characterized the 
 renaissant architecture of Venice, 
 and became the favourite model for 
 the schools of all transalpine coun- 
 tries, especially England. 
 
 In this country, the way was 
 prepared by certain tendencies of 
 our After-Gothic, the florid Per- 
 pendicular, and Tudor; as (I.) the 
 tendency to subordinate the arch 
 and archlet to the framework of 
 vertical and horizontal lines. 
 (II.) By these horizontal masses 
 of moulding beginning almost to 
 approximate the effect of classic 
 entablatures, in their division into 
 two groups, like cornice and archi- 
 trave. (III.) By the roofs being 
 reduced in pitch, and by towers 
 being finished without spires. 
 (IV.) By the depression of the arch, 
 and the diminishing importance 
 attached to its point. (V.) By the 
 introduction of a large and bold 
 scale of carved ornament, and by 
 the introduction of attached orna- 
 ment, contrary to the Gothic prin- 
 ciple of decorating by the removal 
 of superfluous material, and not, as 
 in classic architecture, by addition. 
 These several predisposing ten- 
 dencies of our debased After-Gothic 
 rendered it easy to engraft there- 
 on those Italian details which dis- 
 tinguish the works of the reign 
 of Henry VIII. The chantries of 
 Bishops Fox and Gardiner, at 
 Winchester, are instructive ex- 
 amples of this process ; and so art 
 the tomb of Henry VII., the wood 
 work of King's College chapel, anc 
 
 } )much of the architecture of Cam 
 
 > bridge. 
 
 FKIXTCD BY J. B. TAYLOB, LITTLE QUEB5 STBB.KT, LISCOLS's INN FlfeLDI 
 
 596 
 
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